diff --git a/.github/workflows/pr-check-lint_content.yml b/.github/workflows/pr-check-lint_content.yml
index d9ee293eb809f54..0efe5924c0be468 100644
--- a/.github/workflows/pr-check-lint_content.yml
+++ b/.github/workflows/pr-check-lint_content.yml
@@ -39,14 +39,14 @@ jobs:
           echo "DIFF_DOCUMENTS=${DIFF_DOCUMENTS}" >> $GITHUB_ENV
 
       - name: Checkout HEAD
-        if: ${{ env.DIFF_DOCUMENTS }}
+        if: env.DIFF_DOCUMENTS
         uses: actions/checkout@v4
         with:
           ref: ${{ github.event.pull_request.head.sha }}
           path: pr_head
 
       - name: Get changed content from HEAD
-        if: ${{ env.DIFF_DOCUMENTS }}
+        if: env.DIFF_DOCUMENTS
         run: |
           git config --global user.email "108879845+mdn-bot@users.noreply.github.com"
           git config --global user.name "mdn-bot"
@@ -62,21 +62,21 @@ jobs:
           git commit -m "Code from PR head"
 
       - name: Setup Node.js environment
-        if: ${{ env.DIFF_DOCUMENTS }}
+        if: env.DIFF_DOCUMENTS
         uses: actions/setup-node@v4
         with:
           node-version-file: ".nvmrc"
           cache: yarn
 
       - name: Install all yarn packages
-        if: ${{ env.DIFF_DOCUMENTS }}
+        if: env.DIFF_DOCUMENTS
         run: yarn --frozen-lockfile
         env:
           # https://github.com/microsoft/vscode-ripgrep#github-api-limit-note
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 
       - name: Lint and format markdown files
-        if: ${{ env.DIFF_DOCUMENTS }}
+        if: env.DIFF_DOCUMENTS
         run: |
           # Generate random delimiter
           # https://docs.github.com/en/actions/using-workflows/workflow-commands-for-github-actions#multiline-strings
@@ -120,13 +120,13 @@ jobs:
           git diff
 
       - name: Setup reviewdog
-        if: ${{ env.FILES_MODIFIED == 'true' || env.MD_LINT_FAILED == 'true' }}
+        if: env.FILES_MODIFIED == 'true' || env.MD_LINT_FAILED == 'true'
         uses: reviewdog/action-setup@v1
         with:
           reviewdog_version: latest
 
       - name: Suggest changes using diff
-        if: ${{ env.FILES_MODIFIED == 'true' }}
+        if: env.FILES_MODIFIED == 'true'
         env:
           REVIEWDOG_GITHUB_API_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         run: |
@@ -141,7 +141,7 @@ jobs:
             -reporter=github-pr-review < "${TMPFILE}"
 
       - name: Add reviews for markdownlint errors
-        if: ${{ env.MD_LINT_FAILED == 'true' }}
+        if: env.MD_LINT_FAILED == 'true'
         env:
           REVIEWDOG_GITHUB_API_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         run: |
@@ -154,7 +154,7 @@ jobs:
             -reporter="github-pr-review"
 
       - name: Fail if any issues pending
-        if: ${{ env.FILES_MODIFIED == 'true' || env.MD_LINT_FAILED == 'true' || env.FM_LINT_FAILED == 'true' }}
+        if: env.FILES_MODIFIED == 'true' || env.MD_LINT_FAILED == 'true' || env.FM_LINT_FAILED == 'true'
         env:
           MD_LINT_FAILED: ${{ env.MD_LINT_FAILED }}
           FM_LINT_FAILED: ${{ env.FM_LINT_FAILED }}
diff --git a/.github/workflows/pr-review-companion.yml b/.github/workflows/pr-review-companion.yml
index 00a204522776507..13b3122ee88106d 100644
--- a/.github/workflows/pr-review-companion.yml
+++ b/.github/workflows/pr-review-companion.yml
@@ -7,14 +7,14 @@ name: PR review companion
 
 on:
   workflow_run:
-    workflows: ["PR Test", "PR Test - new CI"]
+    workflows: ["PR Test", "PR Test Legacy"]
     types:
       - completed
 
 jobs:
   review:
     runs-on: ubuntu-latest
-    if: ${{ github.event.workflow_run.conclusion == 'success' }}
+    if: github.event.workflow_run.conclusion == 'success'
     steps:
       - name: "Download artifact"
         uses: actions/download-artifact@v4
@@ -26,18 +26,18 @@ jobs:
           run-id: ${{ github.event.workflow_run.id }}
 
       - name: Check for artifacts
-        if: ${{ hashFiles('build/') != '' }}
+        if: hashFiles('build/') != ''
         run: |
           echo "HAS_ARTIFACT=true" >> "$GITHUB_ENV"
 
       - uses: actions/checkout@v4
-        if: ${{ env.HAS_ARTIFACT }}
+        if: env.HAS_ARTIFACT
         with:
           repository: mdn/yari
           path: yari
 
       - name: Install Python
-        if: ${{ env.HAS_ARTIFACT }}
+        if: env.HAS_ARTIFACT
         id: setup-python
         uses: actions/setup-python@v5
         with:
@@ -45,7 +45,7 @@ jobs:
 
       # See https://www.peterbe.com/plog/install-python-poetry-github-actions-faster
       - name: Load cached ~/.local
-        if: ${{ env.HAS_ARTIFACT }}
+        if: env.HAS_ARTIFACT
         uses: actions/cache@v4
         with:
           path: ~/.local
@@ -54,14 +54,14 @@ jobs:
           key: dotlocal-${{ runner.os }}-${{ steps.setup-python.outputs.python-version }}-0
 
       - name: Install Python poetry
-        if: ${{ env.HAS_ARTIFACT }}
+        if: env.HAS_ARTIFACT
         uses: snok/install-poetry@v1.4
         with:
           virtualenvs-create: true
           virtualenvs-in-project: true
 
       - name: Load cached venv
-        if: ${{ env.HAS_ARTIFACT }}
+        if: env.HAS_ARTIFACT
         id: cached-poetry-dependencies
         uses: actions/cache@v4
         with:
@@ -71,19 +71,19 @@ jobs:
           key: venv-${{ runner.os }}-${{ hashFiles('**/poetry.lock') }}-${{ steps.setup-python.outputs.python-version }}-0
 
       - name: Install poetry dependencies
-        if: ${{ env.HAS_ARTIFACT && steps.cached-poetry-dependencies.outputs.cache-hit != 'true' }}
+        if: env.HAS_ARTIFACT && steps.cached-poetry-dependencies.outputs.cache-hit != 'true'
         run: |
           cd yari/deployer
           poetry install --no-interaction --no-root
 
       - name: Install Deployer
-        if: ${{ env.HAS_ARTIFACT }}
+        if: env.HAS_ARTIFACT
         run: |
           cd yari/deployer
           poetry install --no-interaction
 
       - name: Deploy and analyze built content
-        if: ${{ env.HAS_ARTIFACT }}
+        if: env.HAS_ARTIFACT
         env:
           BUILD_OUT_ROOT: ${{ github.workspace }}/build
 
diff --git a/.github/workflows/pr-test-new-ci.yml b/.github/workflows/pr-test-legacy.yml
similarity index 86%
rename from .github/workflows/pr-test-new-ci.yml
rename to .github/workflows/pr-test-legacy.yml
index 40456d39df87508..e390e19231b95bc 100644
--- a/.github/workflows/pr-test-new-ci.yml
+++ b/.github/workflows/pr-test-legacy.yml
@@ -4,7 +4,7 @@
 # This way, if the tests passed, you'll be able to review the built
 # pages on a public URL.
 
-name: PR Test - new CI
+name: PR Test Legacy
 
 on:
   pull_request:
@@ -13,7 +13,7 @@ on:
 
 jobs:
   tests:
-    if: github.repository == 'mdn/content' && startsWith(github.event.pull_request.title, '[new-ci]')
+    if: github.repository == 'mdn/content'
     runs-on: ubuntu-latest
     # Set the permissions to `read-all`, preventing the workflow from
     # any accidental write access to the repository.
@@ -48,14 +48,14 @@ jobs:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 
       - name: Setup Node.js environment
-        if: ${{ env.GIT_DIFF_CONTENT }} || ${{ env.GIT_DIFF_FILES }}
+        if: env.GIT_DIFF_CONTENT || env.GIT_DIFF_FILES
         uses: actions/setup-node@v4
         with:
           node-version-file: ".nvmrc"
           cache: yarn
 
       - name: Install all yarn packages
-        if: ${{ env.GIT_DIFF_CONTENT }} || ${{ env.GIT_DIFF_FILES }}
+        if: env.GIT_DIFF_CONTENT || env.GIT_DIFF_FILES
         run: yarn --frozen-lockfile
         env:
           # https://github.com/microsoft/vscode-ripgrep#github-api-limit-note
@@ -63,7 +63,7 @@ jobs:
 
       - name: Build changed content
         id: build-content
-        if: ${{ env.GIT_DIFF_CONTENT }}
+        if: env.GIT_DIFF_CONTENT
         env:
           CONTENT_ROOT: ${{ github.workspace }}/files
 
@@ -92,19 +92,12 @@ jobs:
           # Playground
           REACT_APP_PLAYGROUND_BASE_HOST: mdnyalp.dev
 
-          # rari
-          LIVE_SAMPLES_BASE_URL: https://live.mdnyalp.dev
-          INTERACTIVE_EXAMPLES_BASE_URL: https://interactive-examples.mdn.allizom.net
-
         run: |
           # The reason this script isn't in `package.json` is because
           # you don't need that script as a writer. It's only used in CI
           # and it can't use the default CONTENT_ROOT that gets set in
           # package.json.
-          echo Y|yarn rari update
-          ARGS=$(echo $GIT_DIFF_CONTENT | sed -E -e "s#(^| )files#\1-f $PWD/files#g")
-          yarn rari build --no-basic --json-issues --data-issues $ARGS
-          yarn yari-render-html
+          yarn build $GIT_DIFF_CONTENT
 
           echo "Disk usage size of the build"
           du -sh $BUILD_OUT_ROOT
@@ -119,7 +112,7 @@ jobs:
           wget https://github.com/${{ github.repository }}/compare/${BASE_SHA}...${HEAD_SHA}.diff -O ${BUILD_OUT_ROOT}/DIFF
 
       - name: Merge static assets with built documents
-        if: ${{ env.GIT_DIFF_CONTENT }}
+        if: env.GIT_DIFF_CONTENT
         run: |
           # Exclude the .map files, as they're used for debugging JS and CSS.
           rsync -a --exclude "*.map" node_modules/@mdn/yari/client/build/ $BUILD_OUT_ROOT
@@ -127,13 +120,13 @@ jobs:
           du -sh $BUILD_OUT_ROOT
 
       - uses: actions/upload-artifact@v4
-        if: ${{ env.GIT_DIFF_CONTENT }}
+        if: env.GIT_DIFF_CONTENT
         with:
           name: build
           path: ${{ env.BUILD_OUT_ROOT }}
 
       - name: Check changed files
-        if: ${{ env.GIT_DIFF_FILES }}
+        if: env.GIT_DIFF_FILES
         run: |
           echo $GIT_DIFF_FILES
 
diff --git a/.github/workflows/pr-test.yml b/.github/workflows/pr-test.yml
index f3e8d2e5817b9c5..68f3dc5cd3dba5a 100644
--- a/.github/workflows/pr-test.yml
+++ b/.github/workflows/pr-test.yml
@@ -13,7 +13,7 @@ on:
 
 jobs:
   tests:
-    if: github.repository == 'mdn/content' && !startsWith(github.event.pull_request.title, '[new-ci]')
+    if: github.repository == 'mdn/content'
     runs-on: ubuntu-latest
     # Set the permissions to `read-all`, preventing the workflow from
     # any accidental write access to the repository.
@@ -48,14 +48,14 @@ jobs:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 
       - name: Setup Node.js environment
-        if: ${{ env.GIT_DIFF_CONTENT }} || ${{ env.GIT_DIFF_FILES }}
+        if: env.GIT_DIFF_CONTENT || env.GIT_DIFF_FILES
         uses: actions/setup-node@v4
         with:
           node-version-file: ".nvmrc"
           cache: yarn
 
       - name: Install all yarn packages
-        if: ${{ env.GIT_DIFF_CONTENT }} || ${{ env.GIT_DIFF_FILES }}
+        if: env.GIT_DIFF_CONTENT || env.GIT_DIFF_FILES
         run: yarn --frozen-lockfile
         env:
           # https://github.com/microsoft/vscode-ripgrep#github-api-limit-note
@@ -63,7 +63,7 @@ jobs:
 
       - name: Build changed content
         id: build-content
-        if: ${{ env.GIT_DIFF_CONTENT }}
+        if: env.GIT_DIFF_CONTENT
         env:
           CONTENT_ROOT: ${{ github.workspace }}/files
 
@@ -92,12 +92,19 @@ jobs:
           # Playground
           REACT_APP_PLAYGROUND_BASE_HOST: mdnyalp.dev
 
+          # rari
+          LIVE_SAMPLES_BASE_URL: https://live.mdnyalp.dev
+          INTERACTIVE_EXAMPLES_BASE_URL: https://interactive-examples.mdn.allizom.net
+
         run: |
           # The reason this script isn't in `package.json` is because
           # you don't need that script as a writer. It's only used in CI
           # and it can't use the default CONTENT_ROOT that gets set in
           # package.json.
-          yarn build $GIT_DIFF_CONTENT
+          echo Y|yarn rari update
+          ARGS=$(echo $GIT_DIFF_CONTENT | sed -E -e "s#(^| )files#\1-f $PWD/files#g")
+          yarn rari build --no-basic --json-issues --data-issues $ARGS
+          yarn yari-render-html
 
           echo "Disk usage size of the build"
           du -sh $BUILD_OUT_ROOT
@@ -112,7 +119,7 @@ jobs:
           wget https://github.com/${{ github.repository }}/compare/${BASE_SHA}...${HEAD_SHA}.diff -O ${BUILD_OUT_ROOT}/DIFF
 
       - name: Merge static assets with built documents
-        if: ${{ env.GIT_DIFF_CONTENT }}
+        if: env.GIT_DIFF_CONTENT
         run: |
           # Exclude the .map files, as they're used for debugging JS and CSS.
           rsync -a --exclude "*.map" node_modules/@mdn/yari/client/build/ $BUILD_OUT_ROOT
@@ -120,13 +127,13 @@ jobs:
           du -sh $BUILD_OUT_ROOT
 
       - uses: actions/upload-artifact@v4
-        if: ${{ env.GIT_DIFF_CONTENT }}
+        if: env.GIT_DIFF_CONTENT
         with:
           name: build
           path: ${{ env.BUILD_OUT_ROOT }}
 
       - name: Check changed files
-        if: ${{ env.GIT_DIFF_FILES }}
+        if: env.GIT_DIFF_FILES
         run: |
           echo $GIT_DIFF_FILES
 
diff --git a/.vscode/dictionaries/ignore-list.txt b/.vscode/dictionaries/ignore-list.txt
index 0e2e7108138242a..47a0e4a9f06959e 100644
--- a/.vscode/dictionaries/ignore-list.txt
+++ b/.vscode/dictionaries/ignore-list.txt
@@ -112,9 +112,11 @@ dubby
 Duden
 dXNlcm5hbWU6cGFzc3dvcmQ
 EACC
+efregre
 eirmod
 elitr
 ERHGDFy
+ertgrth
 esset
 essum
 Ethere
@@ -173,6 +175,7 @@ isnt
 isoff
 javascripts
 jdoe
+Jgfbgfdgt
 jngl
 jnglstore
 js13kgames
@@ -253,6 +256,7 @@ rebum
 regelialia
 rheeeeet
 ricebean
+rtgtfghhyj
 s3pPLMBiTxaQ9kYGzzhZRbK
 sadipscing
 sagnarelli
@@ -306,6 +310,7 @@ webglsamples
 webvr
 weta
 Whereami
+Whereshire
 wisen
 wisi
 Wookie
diff --git a/.vscode/dictionaries/proper-names.txt b/.vscode/dictionaries/proper-names.txt
index 6afc1f106a836b9..d0b3dd14a522ba2 100644
--- a/.vscode/dictionaries/proper-names.txt
+++ b/.vscode/dictionaries/proper-names.txt
@@ -76,6 +76,7 @@ Béziers
 caitmuenster
 Camino
 Camtasia
+Canva
 Carakan
 Cardano
 carinaanand
@@ -567,6 +568,7 @@ Theora
 Thierry
 Tidwell
 Tink
+tinypng
 Titilayo
 Tokopedia
 Tomayac
diff --git a/.vscode/dictionaries/terms-abbreviations.txt b/.vscode/dictionaries/terms-abbreviations.txt
index c1677803b15560e..4863414becb572c 100644
--- a/.vscode/dictionaries/terms-abbreviations.txt
+++ b/.vscode/dictionaries/terms-abbreviations.txt
@@ -714,6 +714,7 @@ sundried
 sunsetting
 supercookie
 superdomain
+superpowered
 superscaling
 supersets
 SVCB
diff --git a/files/en-us/_redirects.txt b/files/en-us/_redirects.txt
index 425e28f4a45dd41..61c25aad4b1ccdb 100644
--- a/files/en-us/_redirects.txt
+++ b/files/en-us/_redirects.txt
@@ -12791,6 +12791,7 @@
 /en-US/docs/Web/JavaScript/Guide/Inheritance_Revisited	/en-US/docs/Web/JavaScript/Inheritance_and_the_prototype_chain
 /en-US/docs/Web/JavaScript/Guide/Inheritance_and_the_prototype_chain	/en-US/docs/Web/JavaScript/Inheritance_and_the_prototype_chain
 /en-US/docs/Web/JavaScript/Guide/JavaScript_Overview	/en-US/docs/Web/JavaScript/Guide/Introduction
+/en-US/docs/Web/JavaScript/Guide/Numbers_and_dates	/en-US/docs/Web/JavaScript/Guide/Numbers_and_strings
 /en-US/docs/Web/JavaScript/Guide/Obsolete_Pages	/en-US/docs/Web/JavaScript/Guide
 /en-US/docs/Web/JavaScript/Guide/Obsolete_Pages/Block_Statement	/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling
 /en-US/docs/Web/JavaScript/Guide/Obsolete_Pages/Calling_Functions	/en-US/docs/Web/JavaScript/Guide/Functions
@@ -12876,6 +12877,7 @@
 /en-US/docs/Web/JavaScript/Guide/Regular_expressions/Unicode_property_escapes	/en-US/docs/Web/JavaScript/Reference/Regular_expressions/Unicode_character_class_escape
 /en-US/docs/Web/JavaScript/Guide/Sameness	/en-US/docs/Web/JavaScript/Equality_comparisons_and_sameness
 /en-US/docs/Web/JavaScript/Guide/Statements	/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling
+/en-US/docs/Web/JavaScript/Guide/Text_formatting	/en-US/docs/Web/JavaScript/Guide/Numbers_and_strings
 /en-US/docs/Web/JavaScript/Guide/The_Iterator_protocol	/en-US/docs/Web/JavaScript/Reference/Iteration_protocols
 /en-US/docs/Web/JavaScript/Guide/The_legacy_Iterator_protocol	/en-US/docs/Web/JavaScript/Reference/Deprecated_and_obsolete_features
 /en-US/docs/Web/JavaScript/Guide/Using_native_JSON	/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON
diff --git a/files/en-us/_wikihistory.json b/files/en-us/_wikihistory.json
index 0c0776ae71796e0..906cb4966f99e1d 100644
--- a/files/en-us/_wikihistory.json
+++ b/files/en-us/_wikihistory.json
@@ -102176,7 +102176,7 @@
       "douglasnaphas"
     ]
   },
-  "Web/JavaScript/Guide/Numbers_and_dates": {
+  "Web/JavaScript/Guide/Numbers_and_strings": {
     "modified": "2020-11-14T07:27:01.088Z",
     "contributors": [
       "mfuji09",
@@ -102422,31 +102422,6 @@
       "jpmedley"
     ]
   },
-  "Web/JavaScript/Guide/Text_formatting": {
-    "modified": "2020-05-25T10:48:56.137Z",
-    "contributors": [
-      "fscholz",
-      "wbamberg",
-      "bma",
-      "alattalatta",
-      "vriojtg",
-      "sbfraser01",
-      "chrisdavidmills",
-      "JigneshMistry",
-      "stephaniehobson",
-      "SphinxKnight",
-      "amir77ameri",
-      "ThomasEugeneBishop",
-      "nmve",
-      "kdex",
-      "Jeremie",
-      "danielinux7",
-      "gportioli",
-      "xfq",
-      "mahzaib",
-      "kscarfone"
-    ]
-  },
   "Web/JavaScript/Guide/Typed_arrays": {
     "modified": "2020-10-15T21:04:01.905Z",
     "contributors": [
diff --git a/files/en-us/games/techniques/tilemaps/square_tilemaps_implementation_colon__scrolling_maps/index.md b/files/en-us/games/techniques/tilemaps/square_tilemaps_implementation_colon__scrolling_maps/index.md
index ddbee59cf44ac30..f4e19f9d4010054 100644
--- a/files/en-us/games/techniques/tilemaps/square_tilemaps_implementation_colon__scrolling_maps/index.md
+++ b/files/en-us/games/techniques/tilemaps/square_tilemaps_implementation_colon__scrolling_maps/index.md
@@ -19,7 +19,7 @@ Regardless of the type of camera, we would always need information regarding its
 
 - `x` and `y`: The current position of the camera. In this implementation, we are assuming that `(x,y)` points to the top left corner of visible portion of the map.
 - `width` and `height`: The size of the camera's viewport.
-- `maxX` and `maxY`: The limit for the camera's position — The lower limit will nearly always be (0,0), and in this case the upper limit is equal to the size of the world minus the size of the camera's viewport.
+- `maxX` and `maxY`: The limit for the camera's position — The lower limit will nearly always be `(0,0)`, and in this case the upper limit is equal to the size of the world minus the size of the camera's viewport.
 
 ## Rendering the map
 
diff --git a/files/en-us/games/tutorials/html5_gamedev_phaser_device_orientation/index.md b/files/en-us/games/tutorials/html5_gamedev_phaser_device_orientation/index.md
index 050b19aba30ebe6..9c3107f91442f32 100644
--- a/files/en-us/games/tutorials/html5_gamedev_phaser_device_orientation/index.md
+++ b/files/en-us/games/tutorials/html5_gamedev_phaser_device_orientation/index.md
@@ -28,7 +28,7 @@ You can open the index file in your favorite browser to launch the game and try
 
 - `img`: All the images that we will use in the game.
 - `src`: The JavaScript files with all the source code of the game defined inside.
-- `audio:` The sound files used in the game.
+- `audio`: The sound files used in the game.
 
 ## Setting up the Canvas
 
diff --git a/files/en-us/glossary/baseline/typography/index.md b/files/en-us/glossary/baseline/typography/index.md
index f7387b5bae6749b..64b22390066d86e 100644
--- a/files/en-us/glossary/baseline/typography/index.md
+++ b/files/en-us/glossary/baseline/typography/index.md
@@ -14,6 +14,6 @@ Other writing systems have different baselines. For example, Tibetan and similar
 
 ## See also
 
-- [CSS box alignment](/en-US/docs/Web/CSS/CSS_box_alignment#types_of_alignment)
+- [CSS box alignment](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment#types_of_alignment)
 - [CSS inline layout](/en-US/docs/Web/CSS/CSS_inline_layout) module
 - [Baseline (Typography)](<https://en.wikipedia.org/wiki/Baseline_(typography)>) on Wikipedia
diff --git a/files/en-us/glossary/guaranteed_invalid_value/index.md b/files/en-us/glossary/guaranteed_invalid_value/index.md
new file mode 100644
index 000000000000000..4dee2664c7cbc73
--- /dev/null
+++ b/files/en-us/glossary/guaranteed_invalid_value/index.md
@@ -0,0 +1,17 @@
+---
+title: Guaranteed-invalid value
+slug: Glossary/guaranteed_invalid_value
+page-type: glossary-definition
+---
+
+{{GlossarySidebar}}
+
+In CSS the guaranteed-invalid value is {{CSSXref("initial")}}.
+
+When a [custom property](/en-US/docs/Web/CSS/--*)'s value is the guaranteed-invalid value, the {{CSSXref("var")}} function cannot use it for substitution. Attempting to do so makes the declaration _invalid at computed-value time_, unless a valid fallback is specified.
+
+## See also
+
+- CSS {{CSSXref("initial")}}
+- CSS {{CSSXref("var")}}
+- [CSS Custom Properties for Cascading Variables Module Level 1 Specification](https://www.w3.org/TR/css-variables-1/#guaranteed-invalid)
diff --git a/files/en-us/glossary/time_to_first_byte/index.md b/files/en-us/glossary/time_to_first_byte/index.md
index af1e0a5afb123b5..76f6eccbcc6fede 100644
--- a/files/en-us/glossary/time_to_first_byte/index.md
+++ b/files/en-us/glossary/time_to_first_byte/index.md
@@ -8,14 +8,17 @@ page-type: glossary-definition
 
 **Time to First Byte** (TTFB) refers to the time between the browser requesting a page and when it receives the first byte of information from the server. This time includes {{Glossary("DNS")}} lookup and establishing the connection using a {{Glossary("TCP")}} handshake and {{Glossary("TLS")}} handshake if the request is made over {{Glossary("HTTPS")}}.
 
-TTFB is the time it takes between the start of the request and the start of the response, in milliseconds:
+TTFB is the time it takes between the start of the request and the start of the response, in milliseconds. This can be measured using the `{{domxref("PerformanceResourceTiming.requestStart", "requestStart")}}` attribute of {{domxref("PerformanceNavigationTiming")}}:
 
-```plain
-TTFB = responseStart - navigationStart
+```javascript
+const ttfb = performance.getEntriesByType("navigation")[0].responseStart;
 ```
 
+> [!NOTE]
+> For sites using {{HTTPStatus("103", "103 Early Hints")}}, TTFB is typically the _first bytes_ (after any redirects) — and so, the 103 interim response. Site owners wishing to measure the time until the final response should use `{{domxref("PerformanceResourceTiming.finalResponseHeadersStart", "finalResponseHeadersStart")}}`, where supported.
+
 ## See also
 
 - [A typical HTTP session](/en-US/docs/Web/HTTP/Session)
 - [PerformanceResourceTiming](/en-US/docs/Web/API/PerformanceResourceTiming)
-- [PerformanceTiming](/en-US/docs/Web/API/PerformanceTiming)
+- [PerformanceNavigationTiming](/en-US/docs/Web/API/PerformanceNavigationTiming)
diff --git a/files/en-us/learn_web_development/core/accessibility/html/index.md b/files/en-us/learn_web_development/core/accessibility/html/index.md
index 347f10138095f12..080ea658d3043c6 100644
--- a/files/en-us/learn_web_development/core/accessibility/html/index.md
+++ b/files/en-us/learn_web_development/core/accessibility/html/index.md
@@ -497,9 +497,9 @@ This highlights the importance of not only using meaningful file names in case s
 
 Note that the contents of the `alt` attribute should always provide a direct representation of the image and what it conveys visually. The alt should be brief and concise and include all the information conveyed in the image that is not duplicated in the surrounding text.
 
-The content of the `alt` attribute for a single image differs based on the context. For example, if the photo of Fluffy is an avatar next to a review for Yuckymeat dog food, `alt="Fluffy"` is appropriate. If the photo is part of Fluffy's adoption page for the animal rescue society, information conveyed in the image that is relevant for a prospective dog parent that is not duplicated in the surrounding text should be included. A longer description, such as `alt="Fluffy, a tri-color terrier with very short hair, with a tennis ball in her mouth."` is appropriate. As the surrounding text likely has Fluffy's size and breed, that is not included in the `alt`. However, as the dog's biography likely doesn't include hair length, colors, or toy preferences, which the potential parent needs to know, it is included. Is the image outdoors, or does Fluffy have a red collar with a blue leash? Not important in terms of adopting the pet and therefore not included. All information image conveys that a sited user can access and is relevant to the context is what needs to be conveyed; nothing more. Keep it short, precise, and useful.
+The content of the `alt` attribute for a single image differs based on the context. For example, if the photo of Fluffy is an avatar next to a review for Yuckymeat dog food, `alt="Fluffy"` is appropriate. If the photo is part of Fluffy's adoption page for the animal rescue society, information conveyed in the image that is relevant for a prospective dog parent that is not duplicated in the surrounding text should be included. A longer description, such as `alt="Fluffy, a tri-color terrier with very short hair, with a tennis ball in her mouth."` is appropriate. As the surrounding text likely has Fluffy's size and breed, that is not included in the `alt`. However, as the dog's biography likely doesn't include hair length, colors, or toy preferences, which the potential parent needs to know, it is included. Is the image outdoors, or does Fluffy have a red collar with a blue leash? Not important in terms of adopting the pet and therefore not included. All information image conveys that a sighted user can access and is relevant to the context is what needs to be conveyed; nothing more. Keep it short, precise, and useful.
 
-Any personal knowledge or extra description shouldn't be included here, as it is not useful for people who have not seen the image before. If the ball is Fluffy's favorite toy or if the sited user can't know that from the image, then don't include it.
+Any personal knowledge or extra description shouldn't be included here, as it is not useful for people who have not seen the image before. If the ball is Fluffy's favorite toy or if a sighted user can't know that from the image, then don't include it.
 
 One thing to consider is whether your images have meaning inside your content, or whether they are purely for visual decoration, and thus have no meaning. If they are decorative, it is better to write an empty text as a value for `alt` attribute (see [Empty alt attributes](#empty_alt_attributes)) or to just include them in the page as CSS background images.
 
diff --git a/files/en-us/learn_web_development/core/design_for_developers/index.md b/files/en-us/learn_web_development/core/design_for_developers/index.md
index 4a20aac1e88c942..34b8ad9b7065577 100644
--- a/files/en-us/learn_web_development/core/design_for_developers/index.md
+++ b/files/en-us/learn_web_development/core/design_for_developers/index.md
@@ -63,7 +63,7 @@ Learning outcomes:
 Resources:
 
 - [Accessibility overview](/en-US/docs/Learn_web_development/Core/Accessibility)
-- [Inclusive design principles](https://inclusivedesignprinciples.org/), inclusivedesignprinciples.org
+- [Inclusive design principles](https://inclusivedesignprinciples.info/), inclusivedesignprinciples.info
 
 ## Design briefs
 
diff --git a/files/en-us/learn_web_development/core/scripting/functions/index.md b/files/en-us/learn_web_development/core/scripting/functions/index.md
index de9bb13e58fd42f..bcf8de7975872bf 100644
--- a/files/en-us/learn_web_development/core/scripting/functions/index.md
+++ b/files/en-us/learn_web_development/core/scripting/functions/index.md
@@ -356,7 +356,9 @@ function greeting() {
 }
 ```
 
-Both functions you want to call are called `greeting()`, but you can only ever access the `first.js` file's `greeting()` function (the second one is ignored). In addition, an error results when attempting (in the `second.js` file) to assign a new value to the `name` variable — because it was already declared with `const`, and so can't be reassigned.
+You will see that the second script does not load and run at all, and an error is printed in the console: `Uncaught SyntaxError: Identifier 'name' has already been declared`. This is because the `name` constant is already declared in `first.js`, and you can't declare the same constant twice in the same scope. Because the second script did not load, the `greeting()` function from `second.js` is not available to be called. Therefore, you will see an alert box displaying `Hello Chris: welcome to our company.`.
+
+Try removing the second `const name = "Zaptec";` line from `second.js` and reloading the page. Now both scripts execute, and the alert box says `Our company is called Chris.`. Functions are allowed to be redeclared, and the last declaration gets used. The previous declarations are effectively overwritten.
 
 > [!NOTE]
 > You can see this example [running live on GitHub](https://mdn.github.io/learning-area/javascript/building-blocks/functions/conflict.html) (see also the [source code](https://github.com/mdn/learning-area/tree/main/javascript/building-blocks/functions)).
diff --git a/files/en-us/learn_web_development/core/scripting/index.md b/files/en-us/learn_web_development/core/scripting/index.md
index 356a33666ad4a13..7122a2b90620b08 100644
--- a/files/en-us/learn_web_development/core/scripting/index.md
+++ b/files/en-us/learn_web_development/core/scripting/index.md
@@ -12,7 +12,7 @@ JavaScript is a huge topic, with so many different features, styles, and techniq
 
 ## Prerequisites
 
-Before starting this module, you don't need any previous JavaScript knowledge, but you should have worked through the previous modules in the course. You should have at least know [HTML](/en-US/docs/Learn_web_development/Core/Structuring_content) and the [basic fundamentals of CSS](/en-US/docs/Learn_web_development/Core/Styling_basics).
+Before starting this module, you don't need any previous JavaScript knowledge, but you should have worked through the previous modules in the course. You should at least know [HTML](/en-US/docs/Learn_web_development/Core/Structuring_content) and the [basic fundamentals of CSS](/en-US/docs/Learn_web_development/Core/Styling_basics).
 
 > [!NOTE]
 > If you are working on a computer/tablet/other device where you don't have the ability to create your own files, you could try out (most of) the code examples in an online coding program such as [JSBin](https://jsbin.com/) or [Glitch](https://glitch.com/).
diff --git a/files/en-us/learn_web_development/core/scripting/math/index.md b/files/en-us/learn_web_development/core/scripting/math/index.md
index a819a8b331c0b1f..816315c3ae72519 100644
--- a/files/en-us/learn_web_development/core/scripting/math/index.md
+++ b/files/en-us/learn_web_development/core/scripting/math/index.md
@@ -456,7 +456,7 @@ In the next article, we'll explore text and how JavaScript allows us to manipula
 
 ## See also
 
-- [Numbers and dates](/en-US/docs/Web/JavaScript/Guide/Numbers_and_dates)
+- [Numbers and strings](/en-US/docs/Web/JavaScript/Guide/Numbers_and_strings)
 - [Expressions and operators](/en-US/docs/Web/JavaScript/Guide/Expressions_and_operators)
 
 {{PreviousMenuNext("Learn_web_development/Core/Scripting/Variables", "Learn_web_development/Core/Scripting/Strings", "Learn_web_development/Core/Scripting")}}
diff --git a/files/en-us/learn_web_development/core/scripting/what_went_wrong/index.md b/files/en-us/learn_web_development/core/scripting/what_went_wrong/index.md
index 1ef1a9a2ae1cfbe..b62bb416046297d 100644
--- a/files/en-us/learn_web_development/core/scripting/what_went_wrong/index.md
+++ b/files/en-us/learn_web_development/core/scripting/what_went_wrong/index.md
@@ -34,7 +34,7 @@ When you built up the "Guess the number" game in the previous article, you may h
 
 Generally speaking, when you do something wrong in code, there are two main types of error that you'll come across:
 
-- **Syntax errors**: These are spelling errors in your code that actually cause the program not to run at all, or stop working part way through — you will usually be provided with some error messages too. These are usually okay to fix, as long as you are familiar with the right tools and know what the error messages mean!
+- **Syntax errors**: These are spelling errors in your code that actually cause the program not to run at all, or stop working part way through — you will usually be provided with some error messages too. These are usually not too hard to fix, as long as you are familiar with the right tools and know what the error messages mean!
 - **Logic errors**: These are errors where the syntax is actually correct but the code is not what you intended it to be, meaning that program runs successfully but gives incorrect results. These are often harder to fix than syntax errors, as there usually isn't an error message to direct you to the source of the error.
 
 Okay, so it's not quite _that_ simple — there are some other differentiators as you drill down deeper. But the above classifications will do at this early stage in your career. We'll look at both of these types going forward.
diff --git a/files/en-us/learn_web_development/extensions/server-side/django/development_environment/index.md b/files/en-us/learn_web_development/extensions/server-side/django/development_environment/index.md
index 94392fb9ee045e5..0436dcd9942771e 100644
--- a/files/en-us/learn_web_development/extensions/server-side/django/development_environment/index.md
+++ b/files/en-us/learn_web_development/extensions/server-side/django/development_environment/index.md
@@ -426,8 +426,7 @@ In addition to branches, it is possible to create `tags` on any branch and later
 
 ### Create an account and repository on GitHub
 
-First we will create a free account on GitHub.
-With a free account you can't create private repos, but you can create as many _public_ repositories ("repos") as you like.
+First we will create an account on GitHub (this is free).
 Then we create and configure a repository named "django_local_library" for storing the [Local library website](/en-US/docs/Learn_web_development/Extensions/Server-side/Django/Tutorial_local_library_website) as we evolve it in the rest of this tutorial.
 
 The steps are:
diff --git a/files/en-us/learn_web_development/getting_started/environment_setup/browsing_the_web/index.md b/files/en-us/learn_web_development/getting_started/environment_setup/browsing_the_web/index.md
index 87574b2d746f829..62c37f3bc54d5a3 100644
--- a/files/en-us/learn_web_development/getting_started/environment_setup/browsing_the_web/index.md
+++ b/files/en-us/learn_web_development/getting_started/environment_setup/browsing_the_web/index.md
@@ -89,7 +89,7 @@ All web pages can each be found at a unique location (web address, also called a
 
 A _website_ is a collection of linked web pages (plus their associated resources) that share a unique [domain name](/en-US/docs/Learn_web_development/Howto/Web_mechanics/What_is_a_domain_name). Each web page of a given website provides explicit links—most of the time in the form of clickable portions of text—that allow the user to move from one page of the website to another.
 
-When you load your favourite website in a browser, it tends to first display the website's main web page, or _homepage_ (casually referred to as "home"):
+When you load your favorite website in a browser, it tends to first display the website's main web page, or _homepage_ (casually referred to as "home"):
 
 ![Example of a website domain name in the browser address bar](web-site.jpg)
 
@@ -97,7 +97,7 @@ When you load your favourite website in a browser, it tends to first display the
 >
 > **Try it out**
 >
-> Try clicking some menu items or links to look at some different pages on your favourite website.
+> Try clicking some menu items or links to look at some different pages on your favorite website.
 
 > [!NOTE]
 > It is also possible to have a [_single-page app_](/en-US/docs/Glossary/SPA): a website that consists of a single web page that is dynamically updated with new content when needed.
@@ -144,13 +144,13 @@ When you access the web, quite a lot happens between your first interaction (for
    2. When that file is received by the browser, it will start to parse it, and will probably find instructions to make more requests. As discussed above, these might be for files to embed such as images, style information, scripts, and so on.
 4. When all of the resources have been requested, the web browser parses and renders them as required, before displaying the result to the user.
 
-This description of how the web works is heavily simplified, but it is all you really need to know at this point. You will find a more detailed account of how web pages and requested and rendered by a web browser in our [Web standards](/en-US/docs/Learn_web_development/Getting_started/Web_standards) module, slightly later on.
+This description of how the web works is heavily simplified, but it is all you really need to know at this point. You will find a more detailed account of how web pages are requested and rendered by a web browser in our [Web standards](/en-US/docs/Learn_web_development/Getting_started/Web_standards) module, slightly later on.
 
-For now, try opening a web browser and loading up a couple of your favourite sites, thinking about the above steps as you do so.
+For now, try opening a web browser and loading up a couple of your favorite sites, thinking about the above steps as you do so.
 
 ## Searching for information
 
-As a web developer, you will spend a lot of time searching for information, from syntax you can't remember to solutions to specific problems. It is therefore a good idea to learn how to effecively search the web.
+As a web developer, you will spend a lot of time searching for information, from syntax you can't remember to solutions to specific problems. It is therefore a good idea to learn how to effectively search the web.
 
 If you are looking for general information about a specific web technology feature, you should type the name of the feature into the MDN search box. For example, try typing `box model`, `fetch()` or `video element` into the the search box and see what comes up. If you don't find the information you need, try expanding your search — try your search term in a search engine.
 
@@ -208,7 +208,7 @@ As a result, you need to be careful to check the answers they give you, and not
 
   - Typing in `"ant fish cheese"` (with the quotes) will only return results that contain that exact phrase.
   - `"ant cheese" -fish` will return results that contain `ant` and/or `cheese` but not `fish`.
-  - `and OR cheese` will only return results with one term or the other, not both. From our testing, this one only seemed to work effectively in Google.
+  - `ant OR cheese` will only return results with one term or the other, not both. From our testing, this one only seemed to work effectively in Google.
   - `intitle:cheese` will only return results that have "cheese" in the main title of the page.
 
   > [!NOTE]
diff --git a/files/en-us/learn_web_development/getting_started/environment_setup/code_editors/index.md b/files/en-us/learn_web_development/getting_started/environment_setup/code_editors/index.md
index 800fc639d7a0b48..5996e7a997b65a2 100644
--- a/files/en-us/learn_web_development/getting_started/environment_setup/code_editors/index.md
+++ b/files/en-us/learn_web_development/getting_started/environment_setup/code_editors/index.md
@@ -35,7 +35,7 @@ Previously, we told you to install a code editor, as you'll need one to work thr
 
 Before starting to code, you may have had some experience working on text documents in a program like Microsoft Word. You might also be wondering whether you can work with code in these same programs. Unfortunately, the answer is "not really":
 
-- Programs like Micosoft Word are **Binary file** editors; their files contain a non-text format that can only be understood by those programs. Website source code, on the other hand, is stored as plain text.
+- Programs like Microsoft Word are **Binary file** editors; their files contain a non-text format that can only be understood by those programs. Website source code, on the other hand, is stored as plain text.
 - Word _can_ open and edit plain text files, but it doesn't handle them very well. It doesn't have a featureset designed for working with code — it is for writing documents such as letters and reports. You need a program that is designed to cleanly handle and output plain text, and work with code.
 
 You probably already have a plain text editor on your computer. By default, Windows includes [Notepad](https://en.wikipedia.org/wiki/Microsoft_Notepad) and macOS comes with [TextEdit](https://en.wikipedia.org/wiki/TextEdit). Linux distros vary; the Ubuntu 22.04 LTS release comes with [GNOME Text Editor](https://en.wikipedia.org/wiki/GNOME_Text_Editor) by default. Default OS plain text editors can be OK, but they also have a limited feature set.
@@ -87,8 +87,8 @@ Let's try an exercise in VS Code:
 
 VS Code provides other syntax features too. For example:
 
-- You'll see a thin vertical line travelling down from the `function` keyword to the closing curly brace (`}`) — these lines are used to mark different [indentation](https://en.wikipedia.org/wiki/Indentation_style) levels in code, making it easier to identify where blocks begin and end.
-- Also try moving the flashing text cursor over the opening or closing curly brace (`{` or `}`) — you'll see both of them highlighted. This also helps identify the start and end of blocks, and is useful when are trying to find where you are missing a character when you have a more complicated structure with lots of nested blocks. This highlighting also works with other delimeters such as parentheses (`(` and `)`) and square brackets (`[` and `]`).
+- You'll see a thin vertical line traveling down from the `function` keyword to the closing curly brace (`}`) — these lines are used to mark different [indentation](https://en.wikipedia.org/wiki/Indentation_style) levels in code, making it easier to identify where blocks begin and end.
+- Also try moving the flashing text cursor over the opening or closing curly brace (`{` or `}`) — you'll see both of them highlighted. This also helps identify the start and end of blocks, and is useful when are trying to find where you are missing a character when you have a more complicated structure with lots of nested blocks. This highlighting also works with other delimiters such as parentheses (`(` and `)`) and square brackets (`[` and `]`).
 
 ### Code completion/suggestion
 
diff --git a/files/en-us/learn_web_development/getting_started/environment_setup/installing_software/index.md b/files/en-us/learn_web_development/getting_started/environment_setup/installing_software/index.md
index b0bd5f27e6779ab..33a4082ad8c4510 100644
--- a/files/en-us/learn_web_development/getting_started/environment_setup/installing_software/index.md
+++ b/files/en-us/learn_web_development/getting_started/environment_setup/installing_software/index.md
@@ -42,7 +42,7 @@ For now, we would recommend that you install [Visual Studio Code](https://code.v
 Having modern web browsers available to you is essential for web development so that you can test your websites or apps on the browsers your visitors use to access them. You also need to keep your web browsers up-to-date so that they support the latest web technologies and have the latest security fixes applied.
 
 > [!NOTE]
-> Most browswers tend to install updates automatically, applying the changes when they are restarted. You can usually check for updates on the browser "About" page, for example available in the menu at _Firefox_ > _About Firefox_ or _Chrome_ > _About Google Chrome_ on Firefox/Chrome for macOS, or the menu icon > _Help_ > _About Firefox_ or menu icon > _Help_ > _About Google Chrome_ on Firefox/Chrome for Windows.
+> Most browsers tend to install updates automatically, applying the changes when they are restarted. You can usually check for updates on the browser "About" page, for example available in the menu at _Firefox_ > _About Firefox_ or _Chrome_ > _About Google Chrome_ on Firefox/Chrome for macOS, or the menu icon > _Help_ > _About Firefox_ or menu icon > _Help_ > _About Google Chrome_ on Firefox/Chrome for Windows.
 
 For now, you should install a couple of desktop and mobile/alternative device browsers to test your code in. You'll most commonly come across web browsers on desktop, laptop, and mobile devices, but you will also come across web browsers on other devices such as tablets, watches, and TVs. If possible, make sure you have one browser from each line installed and available to test on (so you don't just test in multiple browsers based on the same rendering engine):
 
@@ -71,7 +71,7 @@ One of the easiest options we've found to make a local server available is to us
 4. Press the _Install_ button to install the extension.
 5. Now, when you are working on an HTML file in the editor, you should be able to click the "Show Preview" button to open the live example up in a separate tab.
 
-The above option is simple, but not that flexible. In future, you may want to made a more flexible local server option available that can be used to load examples in any browser you have available. For other options (and more background information around why local servers are neccessary), see [How do you set up a local testing server?](/en-US/docs/Learn_web_development/Howto/Tools_and_setup/set_up_a_local_testing_server).
+The above option is simple, but not that flexible. In future, you may want to made a more flexible local server option available that can be used to load examples in any browser you have available. For other options (and more background information around why local servers are necessary), see [How do you set up a local testing server?](/en-US/docs/Learn_web_development/Howto/Tools_and_setup/set_up_a_local_testing_server).
 
 ## Graphics editors
 
diff --git a/files/en-us/learn_web_development/getting_started/web_standards/the_web_standards_model/index.md b/files/en-us/learn_web_development/getting_started/web_standards/the_web_standards_model/index.md
index 18a7515962b12b7..7cc3aa8a6eb6348 100644
--- a/files/en-us/learn_web_development/getting_started/web_standards/the_web_standards_model/index.md
+++ b/files/en-us/learn_web_development/getting_started/web_standards/the_web_standards_model/index.md
@@ -8,10 +8,7 @@ page-type: tutorial-chapter
 
 {{PreviousMenuNext("Learn_web_development/Getting_started/Web_standards/How_the_web_works", "Learn_web_development/Getting_started/Web_standards/How_browsers_load_websites", "Learn_web_development/Getting_started/Web_standards")}}
 
-> [!NOTE]
-> The content in this article is currently incomplete, sorry about that! We are working hard to improve the MDN Learn Web Development section, and we will have places marked as incomplete ("TODO") finished soon.
-
-This article provides some useful background on the web and web standards — how they came about, what web standard technologies are, and how they work together.
+This article provides some useful background on the web and web standards — how they came about, what web standards technologies are, and how they work together.
 
 <table>
   <tbody>
@@ -25,9 +22,8 @@ This article provides some useful background on the web and web standards — ho
       <th scope="row">Learning outcomes:</th>
       <td>
         <ul>
+          <li>Web standards, and the key principles they are built on.</li>
           <li>How standards bodies operate — for example the <a href="https://www.w3.org/">W3C</a>, <a href="https://whatwg.org/">WHATWG</a>, <a href="https://tc39.es/">TC39</a>, and <a href="https://www.khronos.org/">Khronos Group</a>; the process of standards creation.</li>
-          <li>The lifecycle of web standards features.</li>
-          <li>The key principles web standards are built on.</li>
           <li>The main web standards technologies, and how they work together.</li>
           <li>Web best practices.</li>
         </ul>
@@ -38,64 +34,98 @@ This article provides some useful background on the web and web standards — ho
 
 ## Brief history of the web
 
-We'll keep this very brief, as there are many (more) detailed accounts of the web's history out there, which we'll link to later on (also try searching for "history of the web" in your favorite search engine and see what you get, if you are interested in more detail.)
+In the late 1960s, the US military developed a communication network called [ARPANET](/en-US/docs/Glossary/Arpanet). This can be considered a forerunner of the **internet**, as it worked on [packet switching](https://en.wikipedia.org/wiki/Packet_switching), and featured the first implementation of the [TCP/IP](https://en.wikipedia.org/wiki/Internet_protocol_suite) protocol suite. These two technologies form the basis of the infrastructure that the internet is built on.
 
-In the late 1960s, the US military developed a communication network called [ARPANET](/en-US/docs/Glossary/Arpanet). This can be considered a forerunner of the Web, as it worked on [packet switching](https://en.wikipedia.org/wiki/Packet_switching), and featured the first implementation of the [TCP/IP](https://en.wikipedia.org/wiki/Internet_protocol_suite) protocol suite. These two technologies form the basis of the infrastructure that the internet is built on.
-
-In 1980, Tim Berners-Lee (often referred to as TimBL) wrote a notebook program called ENQUIRE, which featured the concept of links between different nodes. Sound familiar?
+In 1980, [Tim Berners-Lee](https://en.wikipedia.org/wiki/Tim_Berners-Lee) (often referred to as TimBL) wrote a notebook program called ENQUIRE, which featured the concept of links between different nodes. Sound familiar?
 
 Fast forward to 1989, and TimBL wrote [Information Management: A Proposal](https://www.w3.org/History/1989/proposal.html) and HyperText at CERN; these two publications together provided the background for how the web would work. They received a fair amount of interest, enough to convince TimBL's bosses to allow him to go ahead and create a global hypertext system.
 
-By late 1990, TimBL had created all the things needed to run the first version of the web — [HTTP](/en-US/docs/Web/HTTP), [HTML](/en-US/docs/Web/HTML), the first web browser, which was called [WorldWideWeb](https://en.wikipedia.org/wiki/WorldWideWeb), an HTTP server, and some web pages to look at.
+By 1990-91, TimBL had created all the things needed to run the first version of the **World Wide Web** (generally referred to as the **web**) — [HTTP](/en-US/docs/Web/HTTP), [HTML](/en-US/docs/Web/HTML), the first web browser, which was called [WorldWideWeb](https://en.wikipedia.org/wiki/WorldWideWeb), a web server, and some web pages to look at.
+
+> [!NOTE]
+> People sometimes use "the web" and "the internet" interchangeably, but they are different things. The internet is the infrastructure that enables information to be transported around the world between different servers and clients, whereas the web is a system built on top of the internet. The web defines types of information (content and code) that are transported via the internet and communications protocols to manage that transport.
+
+In 1994, TimBL founded the [World Wide Web Consortium](https://en.wikipedia.org/wiki/World_Wide_Web_Consortium) (W3C), an organization that brings together representatives from many different companies to work together on the creation of web technologies. The W3C worked on standardizing and improving existing web technologies such as HTML and HTTP, and creating new technologies such as [CSS](/en-US/docs/Web/CSS) and [JavaScript](/en-US/docs/Web/JavaScript). CSS and JavaScript in particular were vital for giving the web styling and interactivity, making it look more like the web we know today.
 
-In the next few years that followed, the web exploded, with multiple browsers being released, thousands of web servers being set up, and millions of web pages being created. OK, that's a very simple summary of what happened, but we did promise you a brief summary.
+In the next few years that followed, the web exploded, with multiple browsers being released, thousands of web servers being set up, and millions of web pages being created. Other standards organizations also appeared to help standardize different aspects of web technologies.
 
-One last significant data point to share is that in 1994, TimBL founded the [World Wide Web Consortium](https://en.wikipedia.org/wiki/World_Wide_Web_Consortium) (W3C), an organization that brings together representatives from many different technology companies to work together on the creation of web technology specifications. After that other technologies followed such as [CSS](/en-US/docs/Web/CSS) and [JavaScript](/en-US/docs/Web/JavaScript), and the web started to look more like the web we know today.
+> [!NOTE]
+> If you are interested in reading a more detailed account of web history, try searching for "history of the web" in your favorite [search engine](/en-US/docs/Learn_web_development/Getting_started/Environment_setup/Browsing_the_web#search_engine) and see what you can find.
 
 ## Web standards
 
-**Web standards** are the technologies we use to build websites. These standards exist as long technical documents called specifications, which detail exactly how the technology should work. These documents are not very useful for learning how to use the technologies they describe (this is why we have sites like MDN Web Docs), but instead are intended to be used by software engineers to implement these technologies (usually in web browsers).
+**Web standards** are the technologies we use to build websites. These standards exist as long technical documents called specifications, which detail exactly how the technology should work. These documents are not very useful for learning how to use the technologies they describe (this is why we have sites like MDN Web Docs). Instead, they are intended to be used by software engineers to implement these technologies (usually in web browsers).
+
+### Standards bodies and processes
+
+Web standards are created by standards bodies — institutions that invite groups of people from different technology companies to come together and agree on how the technologies should work in the best way to fulfill all of their use cases.
+
+The W3C is the best known web standards body, but there are others. For example:
+
+- [WHATWG](https://whatwg.org/) maintains the [HTML Living Standard](https://html.spec.whatwg.org/multipage/), which describes exactly how HTML (all the HTML elements, and their associated APIs, and other surrounding technologies) should be implemented.
+- [TC39](https://tc39.es/) and [ECMA](https://ecma-international.org/) specify and publish the standard for ECMAScript, which modern JavaScript is based on.
+- [Khronos](https://www.khronos.org/) publish technologies for 3D graphics, such as WebGL.
+
+The full processes by which standards are created can get deep and complex. However, unless you want to create your own web technology features, you don't need to understand most of it. If you want to contribute to the discussion around new technologies and provide feedback, it is usually a matter of joining the relevant mailing list or other discussion mechanism. Standards discussions are carried out in public, hence the term ["Open" standards](#open_standards).
+
+For now, we'll give you a general, high-level understanding of how standards processes work:
+
+1. Someone notices the need for a new web standard feature that will make developers' lives easier. For example, maybe there is a common pattern that is commonly used in web user interfaces, but it is a pain to implement. A dedicated CSS feature would make it much easier. The someone could be anyone — an individual developer, or an engineer working for a big tech company.
+2. The person discusses this feature with other developers, browser engineers, etc., and starts to create interest in implementing the feature. Usually they write an explainer document that explains the need for the feature and how it will work, and a code demo that shows what the feature would look like in action.
+3. If there is enough interest in the feature, it is formally discussed inside the relevant standards body working group. For example, CSS features are usually discussed by the [CSS Working Group](https://www.w3.org/groups/wg/css/) (WG) (see also the [CSS Working Group Wikipedia page](https://en.wikipedia.org/wiki/CSS_Working_Group) for a bit more description and history). Before a new web technology is accepted, it must be rigorously evaluated to make sure it is good for the web — for example, it doesn't introduce any security problems, it is [accessible and compatible](#accessible_and_interoperable) with other web technologies, and it doesn't rely on patents.
+4. To prove out the feature, several things happen. These points can all happen around the same time as Point 3., or even before (browser vendors sometimes implement proprietary/non-standard features and then attempt to standardize them afterwards):
+
+   1. One or more browser vendors will implement an experimental version of the new feature, often disabled by default, but which can be enabled by people who want to test it and provide feedback.
+   2. A working group member will also add it to a technology specification so that browser vendors are able to implement it consistently.
+   3. They will also seek out feedback from other browser vendors to see what issues they have with the proposal, and how likely they are to implement it. These are called Standards positions. See for example [Mozilla Standards Positions](https://mozilla.github.io/standards-positions/).
+   4. Involved individuals will also write an extensive suite of tests to demonstrate that the feature works as described.
 
-For example, the [HTML Living Standard](https://html.spec.whatwg.org/multipage/) describes exactly how HTML (all the HTML elements, and their associated APIs, and other surrounding technologies) should be implemented.
+5. Eventually, if all is well, the feature will be implemented across all browsers and can start being used when creating websites.
 
-Web standards are created by standards bodies — institutions that invite groups of people from different technology companies to come together and agree on how the technologies should work in the best way to fulfill all of their use cases. The W3C is the best known web standards body, but there are others such as the [WHATWG](https://whatwg.org/) (who maintain the living standards for the HTML language), [ECMA](https://ecma-international.org/) (who publish the standard for ECMAScript, which JavaScript is based on), [Khronos](https://www.khronos.org/) (who publish technologies for 3D graphics, such as WebGL), and others.
+> [!NOTE]
+> It is perfectly possible that the people suggesting the feature, implementing it in a browser, creating the specification, writing tests, and collecting feedback on it, are the same person/people.
+
+You can find more information on specific standards body processes. See for example:
 
-### Web standards key principles
+- [W3C Process Document](https://www.w3.org/policies/process/)
+- [WHATWG — Working Mode](https://whatwg.org/working-mode)
+- [The TC39 Process](https://tc39.es/process-document/)
 
-The basic principles of the web:
+## Web standards key principles
 
-- Open to contribute and use.
-- Not patent-encumbered or controlled by a single private entity.
+The key principles of the web, which make the web a unique and exciting industry to get involved in, are as follows:
+
+- Open to contribute and use, and therefore not patent-encumbered or controlled by a single private entity.
 - Accessible and interoperable.
 - They don't break the web.
 
-This basis means that the web is a unique and exciting industry to get involved in.
+Let's look at each of these in a little more detail.
 
 ### "Open" standards
 
-One of the key aspects of web standards, which TimBL and the W3C agreed on from the start, is that the web (and web technologies) should be free to both contribute and use, and not encumbered by patents/licensing. Therefore anyone can write the code to build a website for free, and anyone can contribute to the standards creation process, where the specs are written.
-
-Because web technologies are created openly, in collaboration between many different companies, it means that no one company gets to control them, which is a really good thing. You wouldn't want a single company suddenly deciding to put the entire web behind a paywall, or releasing a new version of HTML that everyone has to buy to continue making websites, or worse still, just deciding they aren't interested any more and just turning it off.
+One of the key aspects of web standards, which TimBL and the W3C agreed on from the start, is that the web (and web technologies) should be **open**. This means they free to both contribute to and use, and not encumbered by patents/licensing. This is important — if a web technology relies on patented/licensed technologies to function, the patent/owner can then charge implementing browser vendors potentially large amounts of of money, and those costs would then be passed onto the browser users.
 
-This allows the web to remain a freely-available public resource.
+In addition, because web technologies are created openly, in collaboration between many different companies, it means that no one company gets to control them, which is a really good thing. You wouldn't want a single company suddenly deciding to put the entire web behind a paywall, or releasing a new version of HTML that everyone has to buy to continue making websites, or worse still, deciding they aren't interested any more and just turning it off.
 
-### Don't break the web
+Open standards enable the web to remain a freely-available public resource, where anyone can write the code to build a website for free, and anyone can contribute to the standards creation process.
 
-Another phrase you'll hear around open web standards is "don't break the web" — the idea is that any new web technology that is introduced should be backwards compatible with what went before it (i.e. old websites will still continue to work), and forwards compatible (future technologies in turn will be compatible with what we currently have). As you go through the learning material presented here, you'll start to learn how this is made possible with some very clever design and implementation work.
+### Accessible and interoperable
 
-## Standards bodies
+The web and web browsers are fundamentally designed so that web content is **accessible** to people with disabilities. It was originally envisaged as a great leveller, enabling people to access information regardless of circumstance. This means that, for example:
 
-[W3C](https://www.w3.org/), [WHATWG](https://whatwg.org/), [TC39](https://tc39.es/), and [Khronos Group](https://www.khronos.org/)
+- People who are unable to use a mouse or pointing device can use the keyboard to navigate the web.
+- People who are visually impaired can magnify content, or use a program called a **screen reader** to read content out to them and describe controls in a way that makes sense.
 
-The full W3C standards process is deep and academic. For now, you should understand how different individuals and companies get involved in the standards process.
+> [!NOTE]
+> You'll learn more about [Accessibility](/en-US/docs/Learn_web_development/Core/Accessibility) later on in the learning pathway.
 
-<!-- TODO? @chrisdavidmills -->
+In addition, web technologies are intended to be **interoperable**. Because web technologies are implemented according to published standards, browsers should provide the same rendered output for a given input (for example, HTML, CSS, or JS code) — in other words, a website should work consistently across multiple browsers.
 
-## The web standards lifecycle
+### Don't break the web
 
-The different maturity stages are designed to weed out issues (e.g. interoperability issues, patent issues).
+Another phrase you'll hear around open web standards is "don't break the web". The idea behind this is that any new web technology should be backwards compatible with what went before it, so existing websites will continue to work in the same way as they did before.
 
-<!-- TODO? @chrisdavidmills -->
+Web browser vendors should be able to implement new web technologies without causing a difference in rendering or functionality that would cause their users to think a website is broken and try another browser as a result.
 
 ## Overview of modern web technologies
 
@@ -107,7 +137,7 @@ There are a number of technologies to learn if you want to be a front-end web de
 
 - HTML is for structure and semantics (meaning).
 - CSS is for styling and layout.
-- JavaScript is for controlling dynamic behavior.
+- JavaScript and APIs are for controlling dynamic behavior.
 
 #### HTML
 
@@ -125,7 +155,7 @@ If we adopted a house-building analogy, HTML would be like the foundations and w
 
 #### CSS
 
-Cascading Style Sheets (**CSS**) is a rule-based language used to apply styles to your HTML — for example, setting text and background colors, adding borders, animating things, or laying out a page in a certain way. As a simple example, the following code would turn our HTML paragraph red:
+Cascading Style Sheets (**CSS**) is a rule-based language used to apply styles to your HTML — for example, setting text and background colors, adding borders, animating things, or laying out a page in a certain way. As a simple example, the following code would turn all HTML paragraphs red:
 
 ```css
 p {
@@ -135,30 +165,32 @@ p {
 
 In the house analogy, CSS is like the paint, wallpaper, carpets and paintings you'd use to make the house look nice.
 
-#### JavaScript
+#### JavaScript (and APIs)
 
-**JavaScript** is the programming language we use to add interactivity to websites, from dynamic style switching, to fetching updates from the server, right through to complex 3D graphics. The following simple JavaScript will store a reference to our paragraph in memory and change the text inside it:
+**JavaScript** is the programming language we use to add interactivity to websites, from dynamic style switching, to fetching updates from the server, right through to complex 3D graphics. The following simple JavaScript store a reference to a paragraph in memory and change the text inside it:
 
 ```js
 let pElem = document.querySelector("p");
 pElem.textContent = "We changed the text!";
 ```
 
-In the house analogy, JavaScript is like the cooker, TV, Microwave, or hairdryer — the things that give your house useful functionality.
+You'll also hear the term **APIs** along with JavaScript. API stands for **Application Programming Interface**. In general terms, an API is a bit of code that allows you to control other more complex bits of code or other functionality on your computer (such as hardware devices like your webcam or microphone) in a manageable way.
 
-#### Separating the layers
+For example, writing your own interface to communicate with your webcam and capture a video stream from it, but the JavaScript [`getUserMedia()`](/en-US/docs/Web/API/MediaDevices/getUserMedia#examples) API method allows you to do this fairly easily. It does all the hard work for you, behind the scenes, so you don't need to reinvent the wheel each time.
 
-Separating the technology layers is a good idea, for:
+The simple code snippet above also uses an API. [`querySelector()`](/en-US/docs/Web/API/Document/querySelector) and [`textContent`](/en-US/docs/Web/API/Node/textContent) are both parts of the [Document Object Model (DOM)](/en-US/docs/Learn_web_development/Core/Scripting/DOM_scripting) family of APIs, which allow you to use JavaScript to manipulate web documents.
 
-- Code management and comprehension.
-- Teamwork/separation of roles.
-- Performance.
+In the house analogy, JavaScript is like the cooker, TV, Microwave, or hairdryer — the things that give your house useful functionality.
+
+### Other web technologies
 
-In reality, the separation is not always clear. It is an ideal to aim for where possible rather than an absolute.
+There are other technologies used on the web, for example:
 
-- A prime example is the case of using JavaScript to dynamically update CSS styling on-the-fly in response to app state changes, user choices, etc.
-- Often this is done by modifying the Element.style.x properties, which results in inline CSS being injected into HTML. A better strategy is to add/change classes on elements to avoid inline CSS.
-- Much more severe is the case of JavaScript frameworks that use various HTML-in-JavaScript or CSS-in-JavaScript custom syntax, which results in a lot of mixing of syntax types.
+- [HTTP](/en-US/docs/Web/HTTP) for communicating between clients and servers, as mentioned earlier.
+- [SVG](/en-US/docs/Web/SVG) for creating and manipulating vector graphics.
+- [MathML](/en-US/docs/Web/MathML) for describing mathematical formulae.
+
+However, HTML, CSS, and JavaScript by far the most important technologies to learn, so we will focus mainly on those in our learning pathway.
 
 ### Tools
 
@@ -166,44 +198,45 @@ Once you've learned the "raw" technologies that can be used to build web pages (
 
 - The [developer tools](/en-US/docs/Learn_web_development/Howto/Tools_and_setup/What_are_browser_developer_tools) inside modern browsers that can be used to debug your code.
 - [Testing tools](/en-US/docs/Learn_web_development/Extensions/Testing) that can be used to run tests to show whether your code is behaving as you intended it to.
-- Libraries and frameworks built on top of JavaScript that allow you to build certain types of website much more quickly and effectively.
-- So-called "Linters", which take a set of rules, look at your code, and highlight places where you haven't followed the rules properly.
-- Minifiers, which remove all the whitespace from your code files to make it so that they are smaller and therefore download from the server more quickly.
+- [Frameworks and libraries](/en-US/docs/Learn_web_development/Core/Frameworks_libraries) built on top of JavaScript that allow you to build certain types of website much more quickly and effectively.
+- So-called **Linters** and **formatters**, which take a set of rules for coding style, look at your code, and update your code to follow those rules. Prettier, which you [met earlier in the course](/en-US/docs/Learn_web_development/Getting_started/Environment_setup/Code_editors#enhancing_your_code_editor_with_extensions), is an example of a formatter.
 
 ### Server-side languages and frameworks
 
 HTML, CSS, and JavaScript are front-end (or client-side) languages, which means they are run by the browser to produce a website front-end that your users can use.
 
-There are another class of languages called back-end (or server-side) languages, meaning that they are run on the server before the result is then sent to the browser to be displayed. A typical use for a server-side language is to get some data out of a database and generate some HTML to contain the data, before then sending the HTML over to the browser to display it to the user.
+There are another class of languages called back-end (or server-side) languages, meaning that they are run on the server before the result is then sent to the browser to be displayed. A typical use for a server-side language is to get some data out of a database, generate some HTML to contain the data, then send the HTML over to the browser to display it to the user.
 
-Example server-side frameworks include ASP.NET (in C#), Django (in Python), Laravel (in PHP), and Next.js (in JavaScript).
+Example server-side frameworks include ASP.NET (C#), Django (Python), Laravel (PHP), and Next.js (JavaScript).
 
 ## Web best practices
 
-We have briefly talked about the technologies that you'll use to build websites. Now let's discuss the best practices you should employ to make sure you are using those technologies in the best way that you can.
+We have briefly talked about the technologies that you'll use to build websites. Now let's discuss the best practices that web developers generally employ to ensure that their websites are usable by as many people as possible.
 
 When doing web development, the main cause of uncertainty comes from the fact that you don't know what combination of technology each user will use to view your website:
 
 - User 1 might be looking at it on an iPhone, with a small, narrow screen.
 - User 2 might be looking at it on a Windows laptop with a widescreen monitor attached to it.
-- User 3 might be blind, and using a screen reader to read the web page out to them.
+- User 3 might be visually impaired, and using a screen reader to read and interact with the web page.
 - User 4 might be using a really old desktop machine that can't run modern browsers.
 
-Because you don't know exactly what your users will use, you need to design defensively — make your website as flexible as possible, so that all of the above users can make use of it, even if they might not all get the same experience. In short, we are trying to make the web work for all, as much as possible.
-
-You'll come across the below concepts at some point in your studies.
-
-- **Progressive enhancement** is the practice of creating a minimal experience that provides the essential functionality to all users, and layering on a better experience and other enhancements in browsers that can support them. Progressive enhancement is often seen as unimportant, because browsers tend to support new features more consistently these days, and people tend to have faster internet connections. However, you should think about examples relevant to the modern day — cutting down on decoration to make a mobile experience smoother and save on data, or providing a simpler, lower-bandwidth experience for users in developing countries who might still pay for home internet by the megabyte.
-- **Cross-browser compatibility** is the practice of trying to make sure your webpage works across as many devices as possible. This includes using technologies that all the browsers support, delivering better experiences to browsers that can handle them (progressive enhancement), and/or writing code so that it falls back to a simpler but still usable experience in older browsers (graceful degradation). It also involves a lot of testing to see if anything fails in certain browsers, and then more work to fix those failures.
-- **Responsive web design** is the practice of making your functionality and layouts flexible so they can automatically adapt to different browsers. An obvious example is a website that is laid out one way in a widescreen browser on the desktop, but displays as a more compact, single-column layout on mobile phone browsers. Try adjusting the width of your browser window now, and see what happens.
-- **Performance** means getting websites to load as quickly as possible, but also making them intuitive and easy to use so that users don't get frustrated and go somewhere else.
-- **Accessibility** means making your websites usable by as many different kinds of people as possible (related concepts are diversity and inclusion, and inclusive design). This includes people with visual impairments, hearing impairments, cognitive disabilities, or physical disabilities. It also goes beyond people with disabilities — how about young or old people, people from different cultures, people using mobile devices, or people with unreliable or slow network connections?
-- **Internationalization** means making websites usable by people from different cultures, who speak different languages to your own. There are technical considerations here (such as altering your layout so that it still works OK for right-to-left, or even vertical languages), and human ones (such as using simple, non-slang language so that people who have your language as their second or third language are more likely to understand your text).
-- **Privacy & Security**. These two concepts are related but different. Privacy refers to allowing people to go about their business privately and not spying on them or collecting more of their data than you absolutely need to. Security refers to constructing your website in a secure way so that malicious users cannot steal information contained on it from you or your users.
-
-## See also
-
-- [History of the World Wide Web](https://en.wikipedia.org/wiki/History_of_the_World_Wide_Web)
-- [How does the internet work?](/en-US/docs/Learn_web_development/Howto/Web_mechanics/How_does_the_Internet_work)
+Because you don't know exactly what your users will use, you need to design defensively — make your website as flexible as possible, so that all of the above users can make use of it, even if they might not all get the same experience.
+
+You'll come across the below concepts at some point in your studies, which represent best practices your websites should ideally adhere to. Don't worry about these too much for now. Throughout most of the course we try to teach these implicitly, meaning that when we teach you HTML, CSS, and JavaScript, our examples will follow the best practices where possible. Later on in your learning journey you will likely explore explicit teachings in these areas.
+
+- **Progressive enhancement**
+  - : Creating a minimal experience that provides the essential functionality to all users, and layering on a better experience and other enhancements in browsers that can support them. Progressive enhancement is often seen as unimportant, because browsers tend to support new features more consistently these days, and people tend to have faster internet connections with higher limits on data usage. However, consider examples like cutting down on decoration to make a mobile experience smoother and save on data or providing a lighter, low-bandwidth experience for users who pay by the megabyte or have metered connections.
+- **Cross-browser compatibility**
+  - : Trying to make sure your webpage works across as many devices as possible. This includes using technologies that all the browsers support, delivering better experiences to browsers that can handle them (progressive enhancement), and/or writing code so that it falls back to a simpler but still usable experience in older browsers (termed **graceful degradation**). It also requires testing to see if anything fails in certain browsers, and then more work to fix those failures.
+- **Separating the layers**
+  - : Putting your content (HTML), styling (CSS), and behavior (JavaScript) in different code files, rather than lumping them all together in the same place. This is a good idea for many reasons, including code management and comprehension and teamwork/separation of roles. In reality, the separation is not always clear. It is an ideal to aim for where possible, rather than an absolute.
+- **Responsive web design**
+  - : Making your functionality and layouts flexible so they can automatically adapt to different browsers. An obvious example is a website that is laid out one way in a widescreen browser on the desktop, but displays as a more compact, single-column layout on mobile phone browsers. Try adjusting the width of your browser window now, and see what happens to the site layout.
+- **Performance**
+  - : Getting websites to load as quickly as possible, but also making them intuitive and easy to use so that users don't get frustrated and go somewhere else.
+- **Internationalization**
+  - : Making websites usable by people from different cultures, who speak different languages to your own. There are technical considerations here (such as altering your layout so that it still works OK for right-to-left or top-to-bottom languages), and human ones (such as using simple, non-slang language so that diverse cultures are more likely to understand your text).
+- **Privacy** & **Security**
+  - : These two concepts are related but different. Privacy refers to allowing people to go about their business privately and not spying on them or collecting more of their data than you absolutely need to. Security refers to constructing your website in a secure way so that malicious users cannot steal information contained on it from you or your users.
 
 {{PreviousMenuNext("Learn_web_development/Getting_started/Web_standards/How_the_web_works", "Learn_web_development/Getting_started/Web_standards/How_browsers_load_websites", "Learn_web_development/Getting_started/Web_standards")}}
diff --git a/files/en-us/mozilla/add-ons/webextensions/api/declarativenetrequest/index.md b/files/en-us/mozilla/add-ons/webextensions/api/declarativenetrequest/index.md
index 9139b6745bc6055..2531e47ebd64c1e 100644
--- a/files/en-us/mozilla/add-ons/webextensions/api/declarativenetrequest/index.md
+++ b/files/en-us/mozilla/add-ons/webextensions/api/declarativenetrequest/index.md
@@ -24,7 +24,7 @@ The `"declarativeNetRequestFeedback"` permission is required to use {{WebExtAPIR
 The declarative rules are defined by four fields:
 
 - `id` – An ID that uniquely identifies a rule within a ruleset. Mandatory and should be >= 1.
-- `priority` – The rule priority. When specified, it should be >= 1. Defaults to 1. See [Matching precedents](#matching_precedents) for details on how priority affects which rules are applied.
+- `priority` – The rule priority. When specified, it should be >= 1. Defaults to 1. See [Matching precedence](#matching_precedence) for details on how priority affects which rules are applied.
 - `condition` – The {{WebExtAPIRef("declarativeNetRequest.RuleCondition","condition")}} under which this rule is triggered.
 - `action` – The {{WebExtAPIRef("declarativeNetRequest.RuleAction","action")}} to take when the rule is matched. Rules can do one of these things:
   - block a network request.
@@ -115,7 +115,7 @@ The number of dynamic and session-scoped rules an extension can add is limited t
 - In Safari and up to Chrome 119 and Firefox 127, the value of {{WebExtAPIRef("declarativeNetRequest.MAX_NUMBER_OF_DYNAMIC_AND_SESSION_RULES","MAX_NUMBER_OF_DYNAMIC_AND_SESSION_RULES")}}.
 - From Chrome 120 and Firefox 128, the values of {{WebExtAPIRef("declarativeNetRequest.MAX_NUMBER_OF_DYNAMIC_RULES","MAX_NUMBER_OF_DYNAMIC_RULES")}} and {{WebExtAPIRef("declarativeNetRequest.MAX_NUMBER_OF_SESSION_RULES","MAX_NUMBER_OF_SESSION_RULES")}}
 
-## Matching precedents
+## Matching precedence
 
 When the browser evaluates how to handle requests, it checks each extension's rules that have a condition that matches the request and chooses the one to consider applying as follows:
 
diff --git a/files/en-us/mozilla/add-ons/webextensions/api/declarativenetrequest/modifyheaderinfo/index.md b/files/en-us/mozilla/add-ons/webextensions/api/declarativenetrequest/modifyheaderinfo/index.md
index 628a353b9679426..4d3993facdd1fcc 100644
--- a/files/en-us/mozilla/add-ons/webextensions/api/declarativenetrequest/modifyheaderinfo/index.md
+++ b/files/en-us/mozilla/add-ons/webextensions/api/declarativenetrequest/modifyheaderinfo/index.md
@@ -13,7 +13,7 @@ The request or response header to modify for a request, declared in the `rule.ac
 
 Each object describes one header modification. To modify multiple headers, multiple objects can be specified in these arrays, or across multiple rules.
 
-Matching `modifyHeaders` rules are applied in the order described at [Matching precedents](/en-US/docs/Mozilla/Add-ons/WebExtensions/API/declarativeNetRequest#matching_precedents).
+Matching `modifyHeaders` rules are applied in the order described at [Matching precedence](/en-US/docs/Mozilla/Add-ons/WebExtensions/API/declarativeNetRequest#matching_precedence).
 Within each extension, all `modifyHeaders` rules with a priority lower than or equal to matching `allow` or `allowAllRequests` rules are ignored.
 
 If multiple `modifyHeaders` rules specify the same header, the resulting modification for the header is determined based on the priority of each rule and the operations specified:
diff --git a/files/en-us/mozilla/add-ons/webextensions/api/declarativenetrequest/rule/index.md b/files/en-us/mozilla/add-ons/webextensions/api/declarativenetrequest/rule/index.md
index 98e1029faaa30f4..7beec4ee35f2398 100644
--- a/files/en-us/mozilla/add-ons/webextensions/api/declarativenetrequest/rule/index.md
+++ b/files/en-us/mozilla/add-ons/webextensions/api/declarativenetrequest/rule/index.md
@@ -22,7 +22,7 @@ Values of this type are objects. They contain these properties:
 - `id`
   - : `number`. An ID that uniquely identifies a rule within a ruleset. Mandatory and should be >= 1.
 - `priority` {{optional_inline}}
-  - : `number`. Rule priority. Defaults to 1. When specified, should be >= 1. See [Matching precedents](/en-US/docs/Mozilla/Add-ons/WebExtensions/API/declarativeNetRequest#matching_precedents) for details on how priority affects which rules are applied.
+  - : `number`. Rule priority. Defaults to 1. When specified, should be >= 1. See [Matching precedence](/en-US/docs/Mozilla/Add-ons/WebExtensions/API/declarativeNetRequest#matching_precedence) for details on how priority affects which rules are applied.
 
 {{WebExtExamples("h2")}}
 
diff --git a/files/en-us/mozilla/add-ons/webextensions/api/declarativenetrequest/ruleaction/index.md b/files/en-us/mozilla/add-ons/webextensions/api/declarativenetrequest/ruleaction/index.md
index 97fc5cee5e3f785..2153f0c8b730dfb 100644
--- a/files/en-us/mozilla/add-ons/webextensions/api/declarativenetrequest/ruleaction/index.md
+++ b/files/en-us/mozilla/add-ons/webextensions/api/declarativenetrequest/ruleaction/index.md
@@ -20,7 +20,7 @@ Values of this type are objects. They contain these properties:
 - `responseHeaders` {{optional_inline}}
   - : {{WebExtAPIRef("declarativeNetRequest.ModifyHeaderInfo")}}. The response headers to modify for the request. Only valid if `type` is `"modifyHeaders"`.
 - `type`
-  - : A `string`. The type of action to perform. Possible values are `"block"`, `"redirect"`, `"allow"`, `"upgradeScheme"`, `"modifyHeaders"`, and `"allowAllRequests"`. The use of the `"redirect"` and `"modifyHeaders"` actions require [host permissions](/en-US/docs/Mozilla/Add-ons/WebExtensions/manifest.json/permissions#host_permissions) for the request and request initiator. The "block" and "upgradeScheme" actions also require host permissions unless the "declarativeNetRequest" permission is specified. Without these permissions, matching rules are ignored. See [Permissions at declarativeNetRequest](/en-US/docs/Mozilla/Add-ons/WebExtensions/API/declarativeNetRequest#permissions) for more information. More details about the effects of rule actions are provided in [Matching precedents](/en-US/docs/Mozilla/Add-ons/WebExtensions/API/declarativeNetRequest#matching_precedents).
+  - : A `string`. The type of action to perform. Possible values are `"block"`, `"redirect"`, `"allow"`, `"upgradeScheme"`, `"modifyHeaders"`, and `"allowAllRequests"`. The use of the `"redirect"` and `"modifyHeaders"` actions require [host permissions](/en-US/docs/Mozilla/Add-ons/WebExtensions/manifest.json/permissions#host_permissions) for the request and request initiator. The "block" and "upgradeScheme" actions also require host permissions unless the "declarativeNetRequest" permission is specified. Without these permissions, matching rules are ignored. See [Permissions at declarativeNetRequest](/en-US/docs/Mozilla/Add-ons/WebExtensions/API/declarativeNetRequest#permissions) for more information. More details about the effects of rule actions are provided in [Matching precedence](/en-US/docs/Mozilla/Add-ons/WebExtensions/API/declarativeNetRequest#matching_precedence).
 
 {{WebExtExamples("h2")}}
 
diff --git a/files/en-us/mozilla/firefox/releases/130/index.md b/files/en-us/mozilla/firefox/releases/130/index.md
index e14e9dedb38a8b5..ea0b860d2be5395 100644
--- a/files/en-us/mozilla/firefox/releases/130/index.md
+++ b/files/en-us/mozilla/firefox/releases/130/index.md
@@ -13,7 +13,7 @@ This article provides information about the changes in Firefox 130 that affect d
 ### HTML
 
 - The [`name`](/en-US/docs/Web/HTML/Element/details#name) attribute of the `<details>` element now allows the grouping of `<details>` elements, where only one element within a group can be open at a time. This allows you to create an exclusive accordion without using JavaScript ([Firefox bug 1856460](https://bugzil.la/1856460) and [Firefox bug 1909613](https://bugzil.la/1909613)).
-- The [`dir`](/en-US/docs/Web/HTML/Global_attributes/dir) and [`lang`](/en-US/docs/Web/HTML/Global_attributes/lang) [global attributes](/en-US/docs/Web/HTML/Global_attributes) now have improved inheritance, including how they work with [shadow DOM](/en-US/docs/Web/API/Web_components/Using_shadow_DOM#attribute_inheritance) ([Firefox bug 1876163](https://bugzil.la/1876163).
+- The [`dir`](/en-US/docs/Web/HTML/Global_attributes/dir) and [`lang`](/en-US/docs/Web/HTML/Global_attributes/lang) [global attributes](/en-US/docs/Web/HTML/Global_attributes) now have improved inheritance, including how they work with [shadow DOM](/en-US/docs/Web/API/Web_components/Using_shadow_DOM#attribute_inheritance) ([Firefox bug 1876163](https://bugzil.la/1876163)).
 
 ### CSS
 
diff --git a/files/en-us/mozilla/firefox/releases/61/index.md b/files/en-us/mozilla/firefox/releases/61/index.md
index 70885cc7f3ca58e..f63a36bf024c7a5 100644
--- a/files/en-us/mozilla/firefox/releases/61/index.md
+++ b/files/en-us/mozilla/firefox/releases/61/index.md
@@ -36,7 +36,7 @@ _No changes._
 
 - CSS parsing has been parallelized ([Firefox bug 1346988](https://bugzil.la/1346988)).
 - Support for {{cssxref("font-variation-settings")}} and {{cssxref("font-optical-sizing")}} has been enabled by default ([Firefox bug 1447163](https://bugzil.la/1447163)).
-- The `grid-gap`, `grid-row-gap`, and `grid-column-gap` properties have been renamed to {{cssxref("gap")}}, {{cssxref("row-gap")}}, and {{cssxref("column-gap")}}, as they are no longer grid-specific ([Firefox bug 1398482](https://bugzil.la/1398482)). See [Box alignment; Gaps between boxes](/en-US/docs/Web/CSS/CSS_box_alignment#gaps_between_boxes) for additional details. The old names have been kept as aliases for web compatibility purposes.
+- The `grid-gap`, `grid-row-gap`, and `grid-column-gap` properties have been renamed to {{cssxref("gap")}}, {{cssxref("row-gap")}}, and {{cssxref("column-gap")}}, as they are no longer grid-specific ([Firefox bug 1398482](https://bugzil.la/1398482)). See [Box alignment; Gaps between boxes](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment#gaps_between_boxes) for additional details. The old names have been kept as aliases for web compatibility purposes.
 - The {{cssxref("flex-basis")}} `content` value is now supported ([Firefox bug 1105111](https://bugzil.la/1105111)).
 - Percentage values of {{cssxref("column-gap")}} are now supported in [CSS multi-column layout](/en-US/docs/Web/CSS/CSS_multicol_layout) ([Firefox bug 1398537](https://bugzil.la/1398537)).
 - The CSS {{cssxref(":host")}} pseudo-class is now supported; this selects a custom element from inside its shadow DOM ([Firefox bug 992245](https://bugzil.la/992245)).
diff --git a/files/en-us/web/accessibility/aria/roles/alertdialog_role/index.md b/files/en-us/web/accessibility/aria/roles/alertdialog_role/index.md
index 2dabe72659a8947..212c3488a535f2e 100644
--- a/files/en-us/web/accessibility/aria/roles/alertdialog_role/index.md
+++ b/files/en-us/web/accessibility/aria/roles/alertdialog_role/index.md
@@ -22,7 +22,7 @@ As the name implies, `alertdialog` is a mashup of the [`dialog`](/en-US/docs/Web
 
 Being a type of dialog, the [`dialog`](/en-US/docs/Web/Accessibility/ARIA/Roles/dialog_role) role's states, properties, and keyboard focus requirements are applicable to the `alertdialog` role as well.
 
-Because of its urgent nature, interrupting the user's workflow, alert dialogs must always be [modal](/en-US/docs/Web/Accessibility/ARIA/Attributes/aria-modal).
+Because of its urgent nature, interrupting the user's workflow, alert dialogs should be [modal](/en-US/docs/Web/Accessibility/ARIA/Attributes/aria-modal).
 
 The alert dialog must have at least one focusable control — such as Confirm, Close, and Cancel — and focus must be moved to that control when the alert dialog appears. Alert dialogs can have additional interactive controls such as text fields and checkboxes.
 
diff --git a/files/en-us/web/api/animation/index.md b/files/en-us/web/api/animation/index.md
index 94b574321cc42ca..148b052a41d069a 100644
--- a/files/en-us/web/api/animation/index.md
+++ b/files/en-us/web/api/animation/index.md
@@ -26,6 +26,8 @@ The **`Animation`** interface of the [Web Animations API](/en-US/docs/Web/API/We
   - : Returns the current finished Promise for this animation.
 - {{domxref("Animation.id")}}
   - : Gets and sets the `String` used to identify the animation.
+- {{domxref("Animation.overallProgress")}} {{ReadOnlyInline}} {{experimental_inline}}
+  - : Returns a number between `0` and `1` indicating the animation's overall progress towards its finished state.
 - {{domxref("Animation.pending")}} {{ReadOnlyInline}}
   - : Indicates whether the animation is currently waiting for an asynchronous operation such as initiating playback or pausing a running animation.
 - {{domxref("Animation.playState")}} {{ReadOnlyInline}}
diff --git a/files/en-us/web/api/animation/overallprogress/index.md b/files/en-us/web/api/animation/overallprogress/index.md
new file mode 100644
index 000000000000000..bf7214bbf8f8ee2
--- /dev/null
+++ b/files/en-us/web/api/animation/overallprogress/index.md
@@ -0,0 +1,149 @@
+---
+title: "Animation: overallProgress property"
+short-title: overallProgress
+slug: Web/API/Animation/overallProgress
+page-type: web-api-instance-property
+status:
+  - experimental
+browser-compat: api.Animation.overallProgress
+---
+
+{{APIRef("Web Animations")}}{{seecompattable}}
+
+The **`overallProgress`** read-only property of the {{domxref("Animation")}} interface returns a number between `0` and `1` indicating the animation's overall progress towards its finished state. This is the overall progress across all of the animation's iterations, not each individual iteration.
+
+`overallProgress` works consistently across all animations, regardless of the type of {{domxref("AnimationTimeline", "timeline")}}.
+
+## Value
+
+A number between `0` and `1`, or `null` if the animation lacks a timeline, is inactive or hasn't been played yet, or if its {{domxref("Animation/currentTime", "currentTime")}} is set to a non-time value.
+
+If the animation's [`iterations`](/en-US/docs/Web/API/KeyframeEffect/KeyframeEffect#iterations) property is set to `Infinity`, or if its {{domxref("Animation/currentTime", "currentTime")}} is set to a negative value, `overallProgress` will return `0`.
+
+If the animation's [`duration`](/en-US/docs/Web/API/KeyframeEffect/KeyframeEffect#duration) is set to `0`, `overallProgress` will return `1`.
+
+## Examples
+
+### Displaying a percentage progress
+
+This demo uses `overallProgress` to create a "percentage progress" readout, which is displayed to the screen while an animation runs.
+
+### HTML
+
+The HTML contains a {{htmlelement("button")}} to press to start the animation, a {{htmlelement("p")}} element in which to display the percentage progress, and a {{htmlelement("div")}} that will be animated.
+
+```html
+<button>Run animation</button>
+<p class="progress">Progress: 0%</p>
+<div class="box"></div>
+```
+
+The demo's CSS provides some rudimentary styling, which is not important for understanding how the JavaScript works, therefore we have hidden it for brevity.
+
+```css hidden
+* {
+  box-sizing: border-box;
+}
+
+html {
+  font-family: Arial, Helvetica, sans-serif;
+}
+
+body {
+  margin: 0;
+  width: 500px;
+  margin: 0 auto;
+  padding: 20px;
+}
+
+.progress {
+  font-weight: bold;
+}
+
+.box {
+  width: 100px;
+  height: 100px;
+  border-radius: 40px 20px;
+  border: 10px solid black;
+  background: lightseagreen;
+  margin: 0 auto;
+}
+```
+
+### JavaScript
+
+In the JavaScript, we start off by grabbing references to the {{htmlelement("button")}}, {{htmlelement("p")}}, and {{htmlelement("div")}} elements.
+
+We then create:
+
+- an `animation` variable which will reference the animation, once we've created it
+- a [keyframes](/en-US/docs/Web/API/Web_Animations_API/Keyframe_Formats) array
+- an options object containing timing properties.
+
+```js
+const btn = document.querySelector("button");
+const progress = document.querySelector(".progress");
+const box = document.querySelector(".box");
+
+let animation;
+
+const keyframes = [{ rotate: "0deg" }, { rotate: "360deg" }];
+
+const timingProps = {
+  duration: 3000,
+  iterations: 1,
+};
+```
+
+Next we add a `"click"` event listener to the `<button>` via [`addEventListener()`](/en-US/docs/Web/API/EventTarget/addEventListener) so that, when pressed, it:
+
+1. Starts the animation running using {{domxref("Element.animate()")}}, passing it the keyframes and options defined earlier and assigning the returned {{domxref("Animation")}} instance to the `animation` variable.
+2. Runs a function called `updateProgress()` via the {{domxref("Window.requestAnimationFrame", "requestAnimationFrame()")}} method, which handles updating the percentage process display.
+
+```js
+btn.addEventListener("click", () => {
+  // Animate the box
+  animation = box.animate(keyframes, timingProps);
+  // Start updating the progress percentage via rAF()
+  requestAnimationFrame(updateProgress);
+});
+```
+
+Now let's define the `updateProgress()` function. This queries {{domxref("Animation.playState")}} to see if the animation is not finished. If it isn't finished, we grab the current value of `overallProgress`, multiplying it by 100 and rounding the result down to convert it to a whole percentage number, then update the `<p>` element's {{domxref("Node.textContent", "textContent")}} value with it. We then call `requestAnimationFrame(updateProgress)` again to re-run the progress percentage update.
+
+If the animation is finished, we replace the percentage progress with a "Finished!" message, and don't call `requestAnimationFrame(updateProgress)`, so the progress percentage updates stop.
+
+```js
+function updateProgress() {
+  // Check if the animation is finished
+  if (animation.playState !== "finished") {
+    // Convert overallProgress to a whole number percentage
+    const progressPercentage = Math.floor(animation.overallProgress * 100);
+    // Update the progress paragraph with the percentage
+    progress.textContent = `Progress: ${progressPercentage}%`;
+    // Only request the next frame if the animation is not finished
+    requestAnimationFrame(updateProgress);
+  } else {
+    progress.textContent = "Finished!";
+  }
+}
+```
+
+### Result
+
+The output looks like this. Try pressing the button to see the animation and associated progress indicator run.
+
+{{ EmbedLiveSample("Displaying a percentage progress", "100%", 250) }}
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{domxref("Animation")}} for other methods and properties you can use to control web page animation.
+- [Web Animations API](/en-US/docs/Web/API/Web_Animations_API)
diff --git a/files/en-us/web/api/cdatasection/index.md b/files/en-us/web/api/cdatasection/index.md
index cf9be80ca0bade0..1420a16e5cac005 100644
--- a/files/en-us/web/api/cdatasection/index.md
+++ b/files/en-us/web/api/cdatasection/index.md
@@ -30,7 +30,7 @@ The only sequence which is not allowed within a CDATA section is the closing seq
 of a CDATA section itself, `]]>`.
 
 > [!NOTE]
-> CDATA sections should not be used within HTML they are considered as comments and not displayed.
+> CDATA sections should not be used within HTML. They are considered comments and are not displayed.
 
 {{InheritanceDiagram}}
 
diff --git a/files/en-us/web/api/console/index.md b/files/en-us/web/api/console/index.md
index e5c309975b96e3f..6b8343068a852eb 100644
--- a/files/en-us/web/api/console/index.md
+++ b/files/en-us/web/api/console/index.md
@@ -127,7 +127,7 @@ console.info("My first car was a", car, ". The object is:", someObject);
 The output will look like this:
 
 ```plain
-My first car was a Dodge Charger. The object is: {str:"Some text", id:5}
+My first car was a Dodge Charger . The object is: {str:"Some text", id:5}
 ```
 
 #### Using string substitutions
diff --git a/files/en-us/web/api/dommatrix/index.md b/files/en-us/web/api/dommatrix/index.md
index f4c4e174e700f37..1d0fa2cbca10b05 100644
--- a/files/en-us/web/api/dommatrix/index.md
+++ b/files/en-us/web/api/dommatrix/index.md
@@ -23,10 +23,6 @@ The interface is available inside [web workers](/en-US/docs/Web/API/Web_Workers_
 
 _This interface inherits properties from {{domxref("DOMMatrixReadOnly")}}, though some of these properties are altered to be mutable._
 
-- `is2D` {{ReadOnlyInline}}
-  - : A Boolean flag whose value is `true` if the matrix was initialized as a 2D matrix. If `false`, the matrix is 3D.
-- `isIdentity` {{ReadOnlyInline}}
-  - : A Boolean whose value is `true` if the matrix is the [identity matrix](https://en.wikipedia.org/wiki/Identity_matrix). The identity matrix is one in which every value is `0` _except_ those on the main diagonal from top-left to bottom-right corner (in other words, where the offsets in each direction are equal).
 - `m11`, `m12`, `m13`, `m14`, `m21`, `m22`, `m23`, `m24`, `m31`, `m32`, `m33`, `m34`, `m41`, `m42`, `m43`, `m44`
   - : Double-precision floating-point values representing each component of a 4×4 matrix, where `m11` through `m14` are the first column, `m21` through `m24` are the second column, and so forth.
 - `a`, `b`, `c`, `d`, `e`, `f`
@@ -106,4 +102,5 @@ The `DOMMatrix` interface is designed with the intent that it will be used for a
 
 ## See also
 
-- Its non-modifiable counterpart, {{domxref("DOMMatrixReadOnly")}}
+- {{domxref("DOMMatrixReadOnly.is2D")}}
+- {{domxref("DOMMatrixReadOnly.isIdentity")}}
diff --git a/files/en-us/web/api/dommatrixreadonly/index.md b/files/en-us/web/api/dommatrixreadonly/index.md
index 943fb6b355eab6b..acba74aadef7f23 100644
--- a/files/en-us/web/api/dommatrixreadonly/index.md
+++ b/files/en-us/web/api/dommatrixreadonly/index.md
@@ -20,10 +20,10 @@ This interface should be available inside [web workers](/en-US/docs/Web/API/Web_
 
 _This interface doesn't inherit any properties._
 
-- `is2D` {{ReadOnlyInline}}
+- {{domxref("DOMMatrixReadOnly.is2D")}} {{ReadOnlyInline}}
   - : A Boolean flag whose value is `true` if the matrix was initialized as a 2D matrix. If `false`, the matrix is 3D.
-- `isIdentity` {{ReadOnlyInline}}
-  - : A Boolean whose value is `true` if the matrix is the [identity matrix](https://en.wikipedia.org/wiki/Identity_matrix). The identity matrix is one in which every value is `0` _except_ those on the main diagonal from top-left to bottom-right corner (in other words, where the offsets in each direction are equal).
+- {{domxref("DOMMatrixReadOnly.isIdentity")}} {{ReadOnlyInline}}
+  - : A Boolean whose value is `true` if the matrix is an [identity matrix](https://en.wikipedia.org/wiki/Identity_matrix).
 - `m11`, `m12`, `m13`, `m14`, `m21`, `m22`, `m23`, `m24`, `m31`, `m32`, `m33`, `m34`, `m41`, `m42`, `m43`, `m44`
   - : Double-precision floating-point values representing each component of a 4×4 matrix, where `m11` through `m14` are the first column, `m21` through `m24` are the second column, and so forth.
 - `a`, `b`, `c`, `d`, `e`, `f`
diff --git a/files/en-us/web/api/dommatrixreadonly/is2d/index.md b/files/en-us/web/api/dommatrixreadonly/is2d/index.md
new file mode 100644
index 000000000000000..2bc9d2eb7b1b5bc
--- /dev/null
+++ b/files/en-us/web/api/dommatrixreadonly/is2d/index.md
@@ -0,0 +1,47 @@
+---
+title: "DOMMatrixReadOnly: is2D property"
+short-title: is2D
+slug: Web/API/DOMMatrixReadOnly/is2D
+page-type: web-api-instance-method
+browser-compat: api.DOMMatrixReadOnly.is2D
+---
+
+{{APIRef("Geometry Interfaces")}}{{AvailableInWorkers}}
+
+The readonly **`is2D`** property of the {{domxref("DOMMatrixReadOnly")}} interface is a Boolean flag that is `true` when the matrix is 2D. The value is `true` if the matrix was initialized as a 2D matrix and only 2D transformation operations were applied. Otherwise, the matrix is defined in 3D, and `is2D` is `false`.
+
+## Value
+
+A Boolean value.
+
+## Examples
+
+```js
+// Initialize a 2D matrix
+const matrix = new DOMMatrix(); // create a matrix
+console.log(matrix.is2D); // output: true
+
+// Transform in a 2D space
+console.log(matrix.rotate(30).is2D); // output: true
+
+// Apply a 3D transform
+console.log(matrix.rotate(10, 20, 1).is2D); // output: false
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{domxref("CSSTransformValue.is2D")}}
+- {{domxref("CSSTransformComponent.is2D")}}
+- CSS {{cssxref("transform-function")}} functions
+- CSS {{cssxref("transform")}} property
+- [CSS transforms](/en-US/docs/Web/CSS/CSS_transforms) module
+- SVG [`transform`](/en-US/docs/Web/SVG/Attribute/transform) attribute
+- {{domxref("CanvasRenderingContext2D")}} interface
diff --git a/files/en-us/web/api/dommatrixreadonly/isidentity/index.md b/files/en-us/web/api/dommatrixreadonly/isidentity/index.md
new file mode 100644
index 000000000000000..829122b8ba309bc
--- /dev/null
+++ b/files/en-us/web/api/dommatrixreadonly/isidentity/index.md
@@ -0,0 +1,49 @@
+---
+title: "DOMMatrixReadOnly: isIdentity property"
+short-title: isIdentity
+slug: Web/API/DOMMatrixReadOnly/isIdentity
+page-type: web-api-instance-method
+browser-compat: api.DOMMatrixReadOnly.isIdentity
+---
+
+{{APIRef("Geometry Interfaces")}}{{AvailableInWorkers}}
+
+The readonly **`isIdentity`** property of the {{domxref("DOMMatrixReadOnly")}} interface is a Boolean whose value is `true` if the matrix is the [identity matrix](https://en.wikipedia.org/wiki/Identity_matrix).
+
+The identity matrix is one in which every value is `0` _except_ those on the main diagonal from top-left to bottom-right corner (in other words, where the offsets in each direction are equal).
+
+## Value
+
+A Boolean value.
+
+## Examples
+
+```js
+// Initialize a 2D matrix
+const matrix = new DOMMatrix(); // create a matrix
+console.log(matrix.isIdentity); // output: true
+
+// Apply a transform that has no effect
+console.log(matrix.translate(0).isIdentity); // output: true
+
+// Apply a transform with effect: this rotates the matrix by 30deg
+console.log(matrix.rotate(30).isIdentity); // output: false
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{domxref("DOMMatrix")}} interface
+- {{domxref("CSSMatrixComponent")}} interface
+- {{domxref("CanvasRenderingContext2D")}} interface
+- CSS {{cssxref("transform-function/matrix()")}} function
+- CSS {{cssxref("transform")}} property
+- [CSS transforms](/en-US/docs/Web/CSS/CSS_transforms) module
+- SVG [`transform`](/en-US/docs/Web/SVG/Attribute/transform) attribute
diff --git a/files/en-us/web/api/element/auxclick_event/index.md b/files/en-us/web/api/element/auxclick_event/index.md
index 6664cdf78183e39..cea059f33c0a9f1 100644
--- a/files/en-us/web/api/element/auxclick_event/index.md
+++ b/files/en-us/web/api/element/auxclick_event/index.md
@@ -29,7 +29,7 @@ A {{domxref("PointerEvent")}}. Inherits from {{domxref("MouseEvent")}}.
 {{InheritanceDiagram("PointerEvent")}}
 
 > [!NOTE]
-> In earlier versions of the specification the event type for this event was a {{domxref("MouseEvent")}}, and this is still the type passed in Firefox and Safari.
+> In earlier versions of the specification, the event type for this event was a {{domxref("MouseEvent")}}. Check [browser compatibility](#browser_compatibility) for more information.
 
 ## Event properties
 
diff --git a/files/en-us/web/api/element/click_event/index.md b/files/en-us/web/api/element/click_event/index.md
index e1bdd209c5e687a..84dd872cd50adcb 100644
--- a/files/en-us/web/api/element/click_event/index.md
+++ b/files/en-us/web/api/element/click_event/index.md
@@ -37,7 +37,7 @@ A {{domxref("PointerEvent")}}. Inherits from {{domxref("MouseEvent")}}.
 {{InheritanceDiagram("PointerEvent")}}
 
 > [!NOTE]
-> In earlier versions of the specification the event type for this event was a {{domxref("MouseEvent")}}, and this is still the type passed in Firefox and Safari.
+> In earlier versions of the specification, the event type for this event was a {{domxref("MouseEvent")}}. Check [browser compatibility](#browser_compatibility) for more information.
 
 ## Event properties
 
diff --git a/files/en-us/web/api/element/contextmenu_event/index.md b/files/en-us/web/api/element/contextmenu_event/index.md
index 851c96190951549..b61ed03bd58bc08 100644
--- a/files/en-us/web/api/element/contextmenu_event/index.md
+++ b/files/en-us/web/api/element/contextmenu_event/index.md
@@ -34,7 +34,7 @@ A {{domxref("PointerEvent")}}. Inherits from {{domxref("MouseEvent")}}.
 {{InheritanceDiagram("PointerEvent")}}
 
 > [!NOTE]
-> In earlier versions of the specification the event type for this event was a {{domxref("MouseEvent")}}, and this is still the type passed in Firefox and Safari.
+> In earlier versions of the specification, the event type for this event was a {{domxref("MouseEvent")}}. Check [browser compatibility](#browser_compatibility) for more information.
 
 ## Event properties
 
diff --git a/files/en-us/web/api/element/nextelementsibling/index.md b/files/en-us/web/api/element/nextelementsibling/index.md
index c03aa5575b78793..20b4808e755e892 100644
--- a/files/en-us/web/api/element/nextelementsibling/index.md
+++ b/files/en-us/web/api/element/nextelementsibling/index.md
@@ -10,7 +10,7 @@ browser-compat: api.Element.nextElementSibling
 
 The **`Element.nextElementSibling`** read-only
 property returns the element immediately following the specified one in its parent's
-children list, or `null` if the specified element is the last one in the list.
+{{domxref("Element.children", "children")}} list, or `null` if the specified element is the last one in the list.
 
 ## Value
 
diff --git a/files/en-us/web/api/element/previouselementsibling/index.md b/files/en-us/web/api/element/previouselementsibling/index.md
index c557fff530fed99..d05618fff932951 100644
--- a/files/en-us/web/api/element/previouselementsibling/index.md
+++ b/files/en-us/web/api/element/previouselementsibling/index.md
@@ -10,7 +10,7 @@ browser-compat: api.Element.previousElementSibling
 
 The **`Element.previousElementSibling`**
 read-only property returns the {{domxref("Element")}} immediately prior to the specified
-one in its parent's children list, or `null` if the specified element is the first one in the list.
+one in its parent's {{domxref("Element.children", "children")}} list, or `null` if the specified element is the first one in the list.
 
 ## Value
 
diff --git a/files/en-us/web/api/eventtarget/addeventlistener/index.md b/files/en-us/web/api/eventtarget/addeventlistener/index.md
index 4191c374ecb1e91..f1342dc124838aa 100644
--- a/files/en-us/web/api/eventtarget/addeventlistener/index.md
+++ b/files/en-us/web/api/eventtarget/addeventlistener/index.md
@@ -79,7 +79,7 @@ addEventListener(type, listener, useCapture)
         If this option is not specified it defaults to `false` – except that in browsers other than Safari, it defaults to `true` for {{domxref("Element/wheel_event", "wheel")}}, {{domxref("Element/mousewheel_event", "mousewheel")}}, {{domxref("Element/touchstart_event", "touchstart")}} and {{domxref("Element/touchmove_event", "touchmove")}} events. See [Using passive listeners](#using_passive_listeners) to learn more.
 
     - `signal` {{optional_inline}}
-      - : An {{domxref("AbortSignal")}}. The listener will be removed when the given `AbortSignal` object's {{domxref("AbortController/abort()", "abort()")}} method is called. If not specified, no `AbortSignal` is associated with the listener.
+      - : An {{domxref("AbortSignal")}}. The listener will be removed when the {{domxref("AbortController/abort()", "abort()")}} method of the {{domxref("AbortController")}} which owns the `AbortSignal` is called. If not specified, no `AbortSignal` is associated with the listener.
 
 - `useCapture` {{optional_inline}}
 
diff --git a/files/en-us/web/api/largestcontentfulpaint/index.md b/files/en-us/web/api/largestcontentfulpaint/index.md
index ea122ded3d30e56..e5a7bdf12eff72b 100644
--- a/files/en-us/web/api/largestcontentfulpaint/index.md
+++ b/files/en-us/web/api/largestcontentfulpaint/index.md
@@ -85,9 +85,13 @@ observer.observe({ type: "largest-contentful-paint", buffered: true });
 
 ### Cross-origin image render time
 
-For security reasons, the value of the {{domxref("LargestContentfulPaint.renderTime", "renderTime")}} property is `0` if the resource is a cross-origin request. Instead the {{domxref("LargestContentfulPaint.loadTime", "loadTime")}} is exposed. To expose cross-origin render time information, the {{HTTPHeader("Timing-Allow-Origin")}} HTTP response header needs to be set.
+For security reasons, the value of the {{domxref("LargestContentfulPaint.renderTime", "renderTime")}} property was originally `0` if the resource is a cross-origin request. Instead the {{domxref("LargestContentfulPaint.loadTime", "loadTime")}} property should be used as a fallback.
 
-For example, to allow `https://developer.mozilla.org` to see `renderTime`, the cross-origin resource should send:
+Browsers [may now expose a slightly coarsened render time](https://github.com/w3c/paint-timing/issues/104) in these situations. Check for [browser support](#browser_compatibility).
+
+To expose more accurate cross-origin render-time information, the {{HTTPHeader("Timing-Allow-Origin")}} HTTP response header needs to be set.
+
+For example, to allow `https://developer.mozilla.org` to see an accurate `renderTime`, the cross-origin resource should send:
 
 ```http
 Timing-Allow-Origin: https://developer.mozilla.org
diff --git a/files/en-us/web/api/largestcontentfulpaint/rendertime/index.md b/files/en-us/web/api/largestcontentfulpaint/rendertime/index.md
index 0936ae95efa3c67..aa6f502c5203d0a 100644
--- a/files/en-us/web/api/largestcontentfulpaint/rendertime/index.md
+++ b/files/en-us/web/api/largestcontentfulpaint/rendertime/index.md
@@ -34,9 +34,13 @@ observer.observe({ type: "largest-contentful-paint", buffered: true });
 
 ### Cross-origin image render time
 
-For security reasons, the value of the `renderTime` property is `0` if the resource is a cross-origin request. Instead the {{domxref("LargestContentfulPaint.loadTime", "loadTime")}} is exposed. To expose cross-origin render time information, the {{HTTPHeader("Timing-Allow-Origin")}} HTTP response header needs to be set.
+For security reasons, the value of the {{domxref("LargestContentfulPaint.renderTime", "renderTime")}} property was originally `0` if the resource is a cross-origin request. Instead the {{domxref("LargestContentfulPaint.loadTime", "loadTime")}} property should be used as a fallback.
 
-For example, to allow `https://developer.mozilla.org` to see `renderTime`, the cross-origin resource should send:
+Browsers [may now expose a slightly coarsened render time](https://github.com/w3c/paint-timing/issues/104) in threse situations. Check for [browser support](#browser_compatibility).
+
+To expose more accurate cross-origin render-time information, the {{HTTPHeader("Timing-Allow-Origin")}} HTTP response header needs to be set.
+
+For example, to allow `https://developer.mozilla.org` to see an accurate `renderTime`, the cross-origin resource should send:
 
 ```http
 Timing-Allow-Origin: https://developer.mozilla.org
diff --git a/files/en-us/web/api/performanceelementtiming/rendertime/index.md b/files/en-us/web/api/performanceelementtiming/rendertime/index.md
index b83d46aed677b55..fa7326bc4681d68 100644
--- a/files/en-us/web/api/performanceelementtiming/rendertime/index.md
+++ b/files/en-us/web/api/performanceelementtiming/rendertime/index.md
@@ -47,9 +47,13 @@ observer.observe({ type: "element", buffered: true });
 
 ### Cross-origin image render time
 
-For security reasons, the value of the `renderTime` property is `0` if the resource is a cross-origin request. To expose cross-origin render time information, the {{HTTPHeader("Timing-Allow-Origin")}} HTTP response header needs to be set.
+For security reasons, the value of the `renderTime` property was originally `0` if the resource is a cross-origin request. Instead the `loadTime` property should be used as a fallback.
 
-For example, to allow `https://developer.mozilla.org` to see `renderTime`, the cross-origin resource should send:
+Browsers [may now expose a slightly coarsened render time](https://github.com/w3c/paint-timing/issues/104) in these situations. Check for [browser support](#browser_compatibility).
+
+To expose more accurate cross-origin render-time information, the {{HTTPHeader("Timing-Allow-Origin")}} HTTP response header needs to be set.
+
+For example, to allow `https://developer.mozilla.org` to see an accurate `renderTime`, the cross-origin resource should send:
 
 ```http
 Timing-Allow-Origin: https://developer.mozilla.org
diff --git a/files/en-us/web/api/performanceresourcetiming/finalresponseheadersstart/index.md b/files/en-us/web/api/performanceresourcetiming/finalresponseheadersstart/index.md
new file mode 100644
index 000000000000000..e2b50bc672699c1
--- /dev/null
+++ b/files/en-us/web/api/performanceresourcetiming/finalresponseheadersstart/index.md
@@ -0,0 +1,103 @@
+---
+title: "PerformanceResourceTiming: finalResponseHeadersStart property"
+short-title: finalResponseHeadersStart
+slug: Web/API/PerformanceResourceTiming/finalResponseHeadersStart
+page-type: web-api-instance-property
+status:
+  - experimental
+browser-compat: api.PerformanceResourceTiming.finalResponseHeadersStart
+---
+
+{{APIRef("Performance API")}}{{AvailableInWorkers}}{{SeeCompatTable}}
+
+The **`finalResponseHeadersStart`** read-only property returns a {{domxref("DOMHighResTimeStamp","timestamp")}} immediately after the browser receives the first byte of the final document response (for example, 200 OK) from the server.
+
+This differs from **`{{domxref("PerformanceResourceTiming.requestStart", "requestStart")}}`** (which may also be represented as **`{{domxref("PerformanceResourceTiming.firstInterimResponseStart", "firstInterimResponseStart")}}`**), as this starts from the first bytes of any response including interim responses (for example, 103 Early Hints) with the final response coming potentially much later.
+
+When there are no interim responses, `requestStart` is the same as `finalResponseHeadersStart` and `firstInterimResponseStart` is 0.
+
+There is no _end_ property for `finalResponseHeadersStart`.
+
+## Value
+
+The `finalResponseHeadersStart` property can have the following values:
+
+- A {{domxref("DOMHighResTimeStamp")}} immediately after the browser receives the first bytes of the final response from the server.
+- `0` if the resource is a cross-origin request and no {{HTTPHeader("Timing-Allow-Origin")}} HTTP response header is used.
+
+## Examples
+
+### Measuring request time
+
+The `finalResponseHeadersStart` and {{domxref("PerformanceResourceTiming.requestStart", "requestStart")}} properties can be used to measure how long it takes for the browser to start receive the final response after the sending the request.
+
+```js
+const request = entry.finalResponseHeadersStart - entry.requestStart;
+```
+
+The following example uses a {{domxref("PerformanceObserver")}} to notify of new `resource` performance entries as they are recorded in the browser's performance timeline. The `buffered` option is used for accessing entries from before the observer creation.
+
+```js
+const observer = new PerformanceObserver((list) => {
+  list.getEntries().forEach((entry) => {
+    const request = entry.finalResponseHeadersStart - entry.requestStart;
+    if (request > 0) {
+      console.log(`${entry.name}: final response time: ${request}ms`);
+    }
+  });
+});
+
+observer.observe({ type: "resource", buffered: true });
+```
+
+The following example uses {{domxref("Performance.getEntriesByType()")}}, which only shows `resource` performance entries present in the browser's performance timeline at the time you call the method.
+
+```js
+const resources = performance.getEntriesByType("resource");
+resources.forEach((entry) => {
+  const request = entry.finalResponseHeadersStart - entry.requestStart;
+  if (request > 0) {
+    console.log(`${entry.name}: final response time: ${request}ms`);
+  }
+});
+```
+
+The following example shows how to measure the time between the first and final response headers.
+
+```js
+const observer = new PerformanceObserver((list) => {
+  list.getEntries().forEach((entry) => {
+    const diff = entry.finalResponseHeadersStart - entry.responseStart;
+    if ((entry.finalResponseHeadersStart > 0) & (diff > 0)) {
+      console.log(
+        `${entry.name}: time between first and final response start: ${diff}ms`,
+      );
+    }
+  });
+});
+
+observer.observe({ type: "resource", buffered: true });
+```
+
+### Cross-origin timing information
+
+If the value of the `finalResponseHeadersStart` property is `0`, the resource might be a cross-origin request. To allow seeing cross-origin timing information, the {{HTTPHeader("Timing-Allow-Origin")}} HTTP response header needs to be set.
+
+For example, to allow `https://developer.mozilla.org` to see timing resources, the cross-origin resource should send:
+
+```http
+Timing-Allow-Origin: https://developer.mozilla.org
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{HTTPHeader("Timing-Allow-Origin")}}
+- {{domxref("PerformanceResourceTiming.firstInterimResponseStart", "firstInterimResponseStart")}}
diff --git a/files/en-us/web/api/performanceresourcetiming/firstinterimresponsestart/index.md b/files/en-us/web/api/performanceresourcetiming/firstinterimresponsestart/index.md
index d1b7fbad836b6ae..d097f6d92a02195 100644
--- a/files/en-us/web/api/performanceresourcetiming/firstinterimresponsestart/index.md
+++ b/files/en-us/web/api/performanceresourcetiming/firstinterimresponsestart/index.md
@@ -19,17 +19,19 @@ There is no _end_ property for `firstInterimResponseStart`.
 The `firstInterimResponseStart` property can have the following values:
 
 - A {{domxref("DOMHighResTimeStamp")}} immediately after the browser receives the first interim bytes of the response from the server.
-- `0` if the resource sent no interim response
+- `0` if the resource sent no interim response.
 - `0` if the resource is a cross-origin request and no {{HTTPHeader("Timing-Allow-Origin")}} HTTP response header is used.
 
 > [!NOTE]
 > As Early Hints are typically only supported on the main navigation request, which is by definition same-origin, a `0` typically indicates Early Hints were **not** used.
 
+When the `firstInterimResponseStart` is non-zero, that indicates it should be the same value as {{domxref("PerformanceResourceTiming.requestStart", "requestStart")}} for [supporting browsers](#browser_compatibility).
+
 ## Examples
 
 ### Measuring request time
 
-The `firstInterimResponseStart` and {{domxref("PerformanceResourceTiming.requestStart", "requestStart")}} properties can be used to measure how long it takes to the browser to receive an interim response after the sending the request.
+The `firstInterimResponseStart` and `requestStart` properties can be used to measure how long it takes to the browser to receive an interim response after the sending the request.
 
 ```js
 const request = entry.firstInterimResponseStart - entry.requestStart;
@@ -83,3 +85,4 @@ Timing-Allow-Origin: https://developer.mozilla.org
 ## See also
 
 - {{HTTPHeader("Timing-Allow-Origin")}}
+- {{domxref("PerformanceResourceTiming.finalResponseHeadersStart", "finalResponseHeadersStart")}}
diff --git a/files/en-us/web/api/performanceresourcetiming/index.md b/files/en-us/web/api/performanceresourcetiming/index.md
index 21840e5fa9bd8af..dcd14d2ab1b90a2 100644
--- a/files/en-us/web/api/performanceresourcetiming/index.md
+++ b/files/en-us/web/api/performanceresourcetiming/index.md
@@ -22,7 +22,7 @@ The properties of this interface allow you to calculate certain resource timing
 - Measuring TCP handshake time (`connectEnd` - `connectStart`)
 - Measuring DNS lookup time (`domainLookupEnd` - `domainLookupStart`)
 - Measuring redirection time (`redirectEnd` - `redirectStart`)
-- Measuring interim request time (`firstInterimResponseStart` - `requestStart`)
+- Measuring interim request time (`firstInterimResponseStart` - `finalResponseHeadersStart`)
 - Measuring request time (`responseStart` - `requestStart`)
 - Measuring TLS negotiation time (`requestStart` - `secureConnectionStart`)
 - Measuring time to fetch (without redirects) (`responseEnd` - `fetchStart`)
@@ -76,7 +76,9 @@ The interface supports the following timestamp properties which you can see in t
 - {{domxref('PerformanceResourceTiming.firstInterimResponseStart')}} {{experimental_inline}} {{ReadOnlyInline}}
   - : A {{domxref("DOMHighResTimeStamp")}} that represents the interim response time (for example, 100 Continue or 103 Early Hints).
 - {{domxref('PerformanceResourceTiming.responseStart')}} {{ReadOnlyInline}}
-  - : A {{domxref("DOMHighResTimeStamp")}} immediately after the browser receives the first byte of the response from the server.
+  - : A {{domxref("DOMHighResTimeStamp")}} immediately after the browser receives the first byte of the response from the server (which may be an interim response).
+- {{domxref('PerformanceResourceTiming.finalResponseHeadersStart')}} {{experimental_inline}} {{ReadOnlyInline}}
+  - : A {{domxref("DOMHighResTimeStamp")}} that represents the final headers response time (for example, 200 Success), after any interim response time.
 - {{domxref('PerformanceResourceTiming.responseEnd')}} {{ReadOnlyInline}}
   - : A {{domxref("DOMHighResTimeStamp")}} immediately after the browser receives the last byte of the resource or immediately before the transport connection is closed, whichever comes first.
 
diff --git a/files/en-us/web/api/performanceresourcetiming/requeststart/index.md b/files/en-us/web/api/performanceresourcetiming/requeststart/index.md
index 9aed4c8621dac18..ca973324432f798 100644
--- a/files/en-us/web/api/performanceresourcetiming/requeststart/index.md
+++ b/files/en-us/web/api/performanceresourcetiming/requeststart/index.md
@@ -20,6 +20,10 @@ The `requestStart` property can have the following values:
 - `0` if the resource was instantaneously retrieved from a cache.
 - `0` if the resource is a cross-origin request and no {{HTTPHeader("Timing-Allow-Origin")}} HTTP response header is used.
 
+When the `firstInterimResponseStart` is non-zero, that indicates it should be the same value as {{domxref("PerformanceResourceTiming.requestStart", "requestStart")}} for [supporting browsers](#browser_compatibility).
+
+When there are no interim responses, `requestStart` is the same as `finalResponseHeadersStart` and `firstInterimResponseStart` is 0.
+
 ## Examples
 
 ### Measuring request time
diff --git a/files/en-us/web/api/pushsubscription/index.md b/files/en-us/web/api/pushsubscription/index.md
index 7c1a2e486b64c94..1ff490cbed41d59 100644
--- a/files/en-us/web/api/pushsubscription/index.md
+++ b/files/en-us/web/api/pushsubscription/index.md
@@ -71,7 +71,7 @@ const subscriptionObject = {
 // Stringify the object an post to the app server
 fetch(`https://example.com/push/`, {
   method: "post",
-  body: JSON.stringify(pushSubscription);
+  body: JSON.stringify(subscriptionObject);
 });
 ```
 
diff --git a/files/en-us/web/api/request/credentials/index.md b/files/en-us/web/api/request/credentials/index.md
index 0179093ad859c4a..170685b1f8e4dbe 100644
--- a/files/en-us/web/api/request/credentials/index.md
+++ b/files/en-us/web/api/request/credentials/index.md
@@ -31,7 +31,7 @@ In the following snippet, we create a new request using the {{domxref("Request.R
 
 ```js
 const request = new Request("flowers.jpg");
-const request = request.request; // returns "same-origin" by default
+const credentials = request.credentials; // returns "same-origin" by default
 ```
 
 ## Specifications
diff --git a/files/en-us/web/api/rtcinboundrtpstreamstats/index.md b/files/en-us/web/api/rtcinboundrtpstreamstats/index.md
index f7cdecaa84f62a5..4a07e77a072cd9c 100644
--- a/files/en-us/web/api/rtcinboundrtpstreamstats/index.md
+++ b/files/en-us/web/api/rtcinboundrtpstreamstats/index.md
@@ -26,6 +26,9 @@ The statistics can be obtained by iterating the {{domxref("RTCStatsReport")}} re
 - {{domxref("RTCInboundRtpStreamStats.lastPacketReceivedTimestamp", "lastPacketReceivedTimestamp")}}
   - : A {{domxref("DOMHighResTimeStamp")}} indicating the time at which the last packet was received for this source.
     The [`timestamp`](#timestamp) property, on the other hand, indicates the time at which the statistics object was generated.
+- {{domxref("RTCInboundRtpStreamStats.mid", "mid")}}
+  - : A string that uniquely identifies the pairing of source and destination of the transceiver's stream.
+    This is the value of the corresponding {{domxref("RTCRtpTransceiver.mid")}} unless that is null, in which case the statistic property is not present.
 - {{domxref("RTCInboundRtpStreamStats.nackCount", "nackCount")}}
   - : An integer value indicating the total number of Negative ACKnowledgement (NACK) packets this receiver has sent.
 - {{domxref("RTCInboundRtpStreamStats.packetsDuplicated", "packetsDuplicated")}}
diff --git a/files/en-us/web/api/rtcinboundrtpstreamstats/mid/index.md b/files/en-us/web/api/rtcinboundrtpstreamstats/mid/index.md
new file mode 100644
index 000000000000000..6ed4e6ff7128f2f
--- /dev/null
+++ b/files/en-us/web/api/rtcinboundrtpstreamstats/mid/index.md
@@ -0,0 +1,24 @@
+---
+title: "RTCInboundRtpStreamStats: mid property"
+short-title: mid
+slug: Web/API/RTCInboundRtpStreamStats/mid
+page-type: web-api-instance-property
+browser-compat: api.RTCStatsReport.type_inbound-rtp.mid
+---
+
+{{APIRef("WebRTC")}}
+
+The **`mid`** property of the {{domxref("RTCInboundRtpStreamStats")}} dictionary is a string that contains the media id negotiated between the local and remote peers.
+This uniquely identifies the pairing of source and destination for the transceiver's stream.
+
+## Value
+
+The value of the corresponding {{domxref("RTCRtpTransceiver.mid")}}, unless that value is null, in which case this statistic property is not present.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
diff --git a/files/en-us/web/api/selection/anchoroffset/index.md b/files/en-us/web/api/selection/anchoroffset/index.md
index df6e7e3e58b3fd1..dac320d465c463f 100644
--- a/files/en-us/web/api/selection/anchoroffset/index.md
+++ b/files/en-us/web/api/selection/anchoroffset/index.md
@@ -10,7 +10,9 @@ browser-compat: api.Selection.anchorOffset
 
 The **`Selection.anchorOffset`** read-only property returns the
 number of characters that the selection's anchor is offset within the
-{{domxref("Selection.anchorNode")}}.
+{{domxref("Selection.anchorNode")}} if said node is of type {{domxref("Text")}}, {{domxref("CDATASection")}} or {{domxref("Comment")}}.
+
+In the case of {{domxref("Selection.anchorNode")}} being another type of node, **`Selection.anchorOffset`** returns the number of {{domxref("Node.childNodes")}} the selection's focus is offset within the {{domxref("Selection.anchorNode")}}.
 
 This number is zero-based. If the selection begins with the first character in the
 {{domxref("Selection.anchorNode")}}, `0` is returned.
diff --git a/files/en-us/web/api/selection/focusoffset/index.md b/files/en-us/web/api/selection/focusoffset/index.md
index 77ba9a61d0e3458..e3340f0763f7f75 100644
--- a/files/en-us/web/api/selection/focusoffset/index.md
+++ b/files/en-us/web/api/selection/focusoffset/index.md
@@ -10,7 +10,9 @@ browser-compat: api.Selection.focusOffset
 
 The **`Selection.focusOffset`** read-only property returns the
 number of characters that the selection's focus is offset within the
-{{domxref("Selection.focusNode")}}.
+{{domxref("Selection.focusNode")}} if said node is of type {{domxref("Text")}}, {{domxref("CDATASection")}} or {{domxref("Comment")}}.
+
+In the case of {{domxref("Selection.focusNode")}} being another type of node, **`Selection.focusOffset`** returns the number of {{domxref("Node.childNodes")}} the selection's focus is offset within the {{domxref("Selection.focusNode")}}.
 
 This number is zero-based. If the selection ends with the first character in the
 {{domxref("Selection.focusNode")}}, `0` is returned.
diff --git a/files/en-us/web/api/selection/index.md b/files/en-us/web/api/selection/index.md
index 894966953d67ae6..c3752d975dbc0fe 100644
--- a/files/en-us/web/api/selection/index.md
+++ b/files/en-us/web/api/selection/index.md
@@ -24,7 +24,7 @@ A user may make a selection from left to right (in document order) or right to l
 - {{DOMxRef("Selection.focusNode")}} {{ReadOnlyInline}}
   - : Returns the {{DOMxRef("Node")}} in which the selection ends. Can return `null` if selection never existed in the document (for example, in an `iframe` that was never clicked on).
 - {{DOMxRef("Selection.focusOffset")}} {{ReadOnlyInline}}
-  - : Returns a number representing the offset of the selection's anchor within the `focusNode`. If `focusNode` is a text node, this is the number of characters within `focusNode` preceding the focus. If `focusNode` is an element, this is the number of child nodes of the `focusNode` preceding the focus.
+  - : Returns a number representing the offset of the selection's focus within the `focusNode`. If `focusNode` is a text node, this is the number of characters within `focusNode` preceding the focus. If `focusNode` is an element, this is the number of child nodes of the `focusNode` preceding the focus.
 - {{DOMxRef("Selection.isCollapsed")}} {{ReadOnlyInline}}
   - : Returns a Boolean indicating whether the selection's start and end points are at the same position.
 - {{DOMxRef("Selection.rangeCount")}} {{ReadOnlyInline}}
diff --git a/files/en-us/web/api/svgangle/unittype/index.md b/files/en-us/web/api/svgangle/unittype/index.md
index d14ba2fe4e21600..358056fc4209cbc 100644
--- a/files/en-us/web/api/svgangle/unittype/index.md
+++ b/files/en-us/web/api/svgangle/unittype/index.md
@@ -8,7 +8,7 @@ browser-compat: api.SVGAngle.unitType
 
 {{APIRef("SVG")}}
 
-The **`unitType`** property of the {{domxref("SVGAngle")}} interface is one of the [unit type contants](/en-US/docs/Web/API/SVGAngle#constants) and represents the units in which this angle's value is expressed.
+The **`unitType`** property of the {{domxref("SVGAngle")}} interface is one of the [unit type constants](/en-US/docs/Web/API/SVGAngle#constants) and represents the units in which this angle's value is expressed.
 
 ## Value
 
diff --git a/files/en-us/web/api/svgfedropshadowelement/height/index.md b/files/en-us/web/api/svgfedropshadowelement/height/index.md
new file mode 100644
index 000000000000000..d5f087cd8a336f4
--- /dev/null
+++ b/files/en-us/web/api/svgfedropshadowelement/height/index.md
@@ -0,0 +1,42 @@
+---
+title: "SVGFEDropShadowElement: height property"
+short-title: height
+slug: Web/API/SVGFEDropShadowElement/height
+page-type: web-api-instance-property
+browser-compat: api.SVGFEDropShadowElement.height
+---
+
+{{APIRef("SVG")}}
+
+The **`height`** read-only property of the {{domxref("SVGFEDropShadowElement")}} interface describes the vertical size of an SVG filter primitive as a {{domxref("SVGAnimatedLength")}}.
+
+It reflects the {{SVGAttr("height")}} filter primitive attribute. The attribute is a [`<length>`](/en-US/docs/Web/SVG/Content_type#length) or a [`<percentage>`](/en-US/docs/Web/SVG/Content_type#percentage) relative to the height of the filter region. The default value is `100%`. The property value is a length in user coordinate system units.
+
+## Value
+
+An {{domxref("SVGAnimatedLength")}}.
+
+## Example
+
+```js
+const feDropShadow = document.querySelector("feDropShadow");
+const verticalSize = feDropShadow.height;
+console.log(verticalSize.baseVal.value); // the `height` value
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{domxref("SVGFEDropShadowElement.width")}}
+- CSS {{cssxref("filter-function/drop-shadow", "drop-shadow()")}} function
+- CSS {{cssxref("box-shadow")}} property
+- CSS {{cssxref("text-shadow")}} property
+- CSS {{cssxref("blend-mode")}} data type
+- CSS {{cssxref("mix-blend-mode")}} property
diff --git a/files/en-us/web/api/svgfedropshadowelement/result/index.md b/files/en-us/web/api/svgfedropshadowelement/result/index.md
new file mode 100644
index 000000000000000..4c9929942652c7d
--- /dev/null
+++ b/files/en-us/web/api/svgfedropshadowelement/result/index.md
@@ -0,0 +1,45 @@
+---
+title: "SVGFEDropShadowElement: result property"
+short-title: result
+slug: Web/API/SVGFEDropShadowElement/result
+page-type: web-api-instance-property
+browser-compat: api.SVGFEDropShadowElement.result
+---
+
+{{APIRef("SVG")}}
+
+The **`result`** read-only property of the {{domxref("SVGFEDropShadowElement")}} interface describes the assigned name of an SVG filter primitive as a {{domxref("SVGAnimatedString")}}.
+
+It reflects the {{SVGAttr("result")}} attribute. The attribute value is a {{cssxref("custom-ident")}}. If supplied, then graphics that result from processing this filter primitive can be referenced by an {{SVGAttr("in")}} attribute on a subsequent filter primitive within the same {{SVGElement("filter")}} element.
+
+If no `result` attribute is defined, the filter's `result.baseVal` and `result.animVal` are empty strings, and the output of the `<feDropShadow>` filter will only be available for re-use as the implicit input into the next filter primitive if that filter primitive provides no value for its `in` attribute.
+
+## Value
+
+An {{domxref("SVGAnimatedString")}}.
+
+## Example
+
+```js
+const feDropShadowElement = document.querySelector("feDropShadow");
+const filterName = feDropShadowElement.result;
+console.log(filterName.baseVal); // the filter's assigned name
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{domxref("SVGFEDropShadowElement.in1")}}
+- {{cssxref("custom-ident")}} data type
+- CSS {{cssxref("filter-function/drop-shadow", "drop-shadow()")}} function
+- CSS {{cssxref("box-shadow")}} property
+- CSS {{cssxref("text-shadow")}} property
+- CSS {{cssxref("blend-mode")}} data type
+- CSS {{cssxref("mix-blend-mode")}} property
diff --git a/files/en-us/web/api/svgfedropshadowelement/width/index.md b/files/en-us/web/api/svgfedropshadowelement/width/index.md
new file mode 100644
index 000000000000000..d698a58b79e7281
--- /dev/null
+++ b/files/en-us/web/api/svgfedropshadowelement/width/index.md
@@ -0,0 +1,42 @@
+---
+title: "SVGFEDropShadowElement: width property"
+short-title: width
+slug: Web/API/SVGFEDropShadowElement/width
+page-type: web-api-instance-property
+browser-compat: api.SVGFEDropShadowElement.width
+---
+
+{{APIRef("SVG")}}
+
+The **`width`** read-only property of the {{domxref("SVGFEDropShadowElement")}} interface describes the horizontal size of an SVG filter primitive as a {{domxref("SVGAnimatedLength")}}.
+
+It reflects the {{SVGAttr("width")}} filter primitive attribute. The attribute is a [`<length>`](/en-US/docs/Web/SVG/Content_type#length) or a [`<percentage>`](/en-US/docs/Web/SVG/Content_type#percentage) relative to the width of the filter region. The default value is `100%`. The property value is a length in user coordinate system units.
+
+## Value
+
+An {{domxref("SVGAnimatedLength")}}.
+
+## Example
+
+```js
+const feDropShadow = document.querySelector("feDropShadow");
+const horizontalSize = feDropShadow.width;
+console.log(horizontalSize.baseVal.value); // the `width` value
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{domxref("SVGFEDropShadowElement.height")}}
+- CSS {{cssxref("filter-function/drop-shadow", "drop-shadow()")}} function
+- CSS {{cssxref("box-shadow")}} property
+- CSS {{cssxref("text-shadow")}} property
+- CSS {{cssxref("blend-mode")}} data type
+- CSS {{cssxref("mix-blend-mode")}} property
diff --git a/files/en-us/web/api/svgfedropshadowelement/x/index.md b/files/en-us/web/api/svgfedropshadowelement/x/index.md
new file mode 100644
index 000000000000000..0f90d3d2a9b177a
--- /dev/null
+++ b/files/en-us/web/api/svgfedropshadowelement/x/index.md
@@ -0,0 +1,42 @@
+---
+title: "SVGFEDropShadowElement: x property"
+short-title: x
+slug: Web/API/SVGFEDropShadowElement/x
+page-type: web-api-instance-property
+browser-compat: api.SVGFEDropShadowElement.x
+---
+
+{{APIRef("SVG")}}
+
+The **`x`** read-only property of the {{domxref("SVGFEDropShadowElement")}} interface describes the horizontal coordinate of the position of an SVG filter primitive as a {{domxref("SVGAnimatedLength")}}.
+
+It reflects the {{SVGAttr("x")}} attribute of the {{SVGElement("feDropShadow")}} element, which creates a drop shadow of an input image. The attribute is a [`<length>`](/en-US/docs/Web/SVG/Content_type#length) or [`<percentage>`](/en-US/docs/Web/SVG/Content_type#percentage). The `<coordinate>` is a length in the user coordinate system that is the given distance from the origin of the user coordinate system along the x-axis. If the `x` attribute is a percent value, the property value is relative to the width of the filter region in user coordinate system units.
+
+## Value
+
+An {{domxref("SVGAnimatedLength")}}.
+
+## Example
+
+```js
+const feDropShadow = document.querySelector("feDropShadow");
+const leftPosition = feDropShadow.x;
+console.log(leftPosition.baseVal.value); // the `x` value
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{domxref("SVGFEDropShadowElement.y")}}
+- CSS {{cssxref("filter-function/drop-shadow", "drop-shadow()")}} function
+- CSS {{cssxref("box-shadow")}} property
+- CSS {{cssxref("text-shadow")}} property
+- CSS {{cssxref("blend-mode")}} data type
+- CSS {{cssxref("mix-blend-mode")}} property
diff --git a/files/en-us/web/api/svgfedropshadowelement/y/index.md b/files/en-us/web/api/svgfedropshadowelement/y/index.md
new file mode 100644
index 000000000000000..d832badd3549e92
--- /dev/null
+++ b/files/en-us/web/api/svgfedropshadowelement/y/index.md
@@ -0,0 +1,42 @@
+---
+title: "SVGFEDropShadowElement: y property"
+short-title: "y"
+slug: Web/API/SVGFEDropShadowElement/y
+page-type: web-api-instance-property
+browser-compat: api.SVGFEDropShadowElement.y
+---
+
+{{APIRef("SVG")}}
+
+The **`y`** read-only property of the {{domxref("SVGFEDropShadowElement")}} interface describes the vertical coordinate of the position of an SVG filter primitive as a {{domxref("SVGAnimatedLength")}}.
+
+It reflects the {{SVGAttr("y")}} attribute of the {{SVGElement("feDropShadow")}} element, which creates a drop shadow of an input image. The attribute is a [`<length>`](/en-US/docs/Web/SVG/Content_type#length) or [`<percentage>`](/en-US/docs/Web/SVG/Content_type#percentage). The `<coordinate>` is a length in the user coordinate system that is the given distance from the origin of the filter along the y-axis. If the `y` attribute is a percent value, the property value is a relative to the height of the filter region in user coordinate system units. The default value is `0`.
+
+## Value
+
+An {{domxref("SVGAnimatedLength")}}.
+
+## Example
+
+```js
+const feDropShadow = document.querySelector("feDropShadow");
+const topPosition = feDropShadow.y;
+console.log(topPosition.baseVal.value); // the `y` value
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{domxref("SVGFEDropShadowElement.x")}}
+- CSS {{cssxref("filter-function/drop-shadow", "drop-shadow()")}} function
+- CSS {{cssxref("box-shadow")}} property
+- CSS {{cssxref("text-shadow")}} property
+- CSS {{cssxref("blend-mode")}} data type
+- CSS {{cssxref("mix-blend-mode")}} property
diff --git a/files/en-us/web/api/svgfefloodelement/height/index.md b/files/en-us/web/api/svgfefloodelement/height/index.md
new file mode 100644
index 000000000000000..f935e4e67b6829b
--- /dev/null
+++ b/files/en-us/web/api/svgfefloodelement/height/index.md
@@ -0,0 +1,39 @@
+---
+title: "SVGFEFloodElement: height property"
+short-title: height
+slug: Web/API/SVGFEFloodElement/height
+page-type: web-api-instance-property
+browser-compat: api.SVGFEFloodElement.height
+---
+
+{{APIRef("SVG")}}
+
+The **`height`** read-only property of the {{domxref("SVGFEFloodElement")}} interface describes the vertical size of an SVG filter primitive as a {{domxref("SVGAnimatedLength")}}.
+
+It reflects the {{SVGAttr("height")}} attribute of the {{SVGElement("feFlood")}} element, which fills an SVG filter subregion with the color and opacity defined by {{SVGAttr("flood-color")}} and {{SVGAttr("flood-opacity")}}. The attribute is a [`<length>`](/en-US/docs/Web/SVG/Content_type#length) or a [`<percentage>`](/en-US/docs/Web/SVG/Content_type#percentage) relative to the height of the filter region. The default value is `100%`. The property value is a length in user coordinate system units.
+
+## Value
+
+An {{domxref("SVGAnimatedLength")}}.
+
+## Example
+
+```js
+const feFlood = document.querySelector("feFlood");
+const verticalSize = feFlood.height;
+console.log(verticalSize.baseVal.value); // the `height` value
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{domxref("SVGFEFloodElement.width")}}- [SVG filter tutorial](/en-US/docs/Web/SVG/Tutorial/SVG_Filters_Tutorial)
+- CSS {{cssxref("blend-mode")}} data type
+- CSS {{cssxref("mix-blend-mode")}} property
diff --git a/files/en-us/web/api/svgfefloodelement/result/index.md b/files/en-us/web/api/svgfefloodelement/result/index.md
new file mode 100644
index 000000000000000..804bbd5873981d8
--- /dev/null
+++ b/files/en-us/web/api/svgfefloodelement/result/index.md
@@ -0,0 +1,42 @@
+---
+title: "SVGFEFloodElement: result property"
+short-title: result
+slug: Web/API/SVGFEFloodElement/result
+page-type: web-api-instance-property
+browser-compat: api.SVGFEFloodElement.result
+---
+
+{{APIRef("SVG")}}
+
+The **`result`** read-only property of the {{domxref("SVGFEFloodElement")}} interface describes the assigned name of an SVG filter primitive as a {{domxref("SVGAnimatedString")}}.
+
+It reflects the {{SVGAttr("result")}} attribute of the {{SVGElement("feFlood")}} element, which fills an SVG filter subregion with the color and opacity defined by {{SVGAttr("flood-color")}} and {{SVGAttr("flood-opacity")}}. The attribute value is a {{cssxref("custom-ident")}}. If supplied, then graphics that result from processing this filter primitive can be referenced by an {{SVGAttr("in")}} attribute on a subsequent filter primitive within the same {{SVGElement("filter")}} element.
+
+If no `result` attribute is defined, the filter's `result.baseVal` and `result.animVal` are empty strings, and the output of the `<feFlood>` filter will only be available for re-use as the implicit input into the next filter primitive if that filter primitive provides no value for its `in` attribute.
+
+## Value
+
+An {{domxref("SVGAnimatedString")}}.
+
+## Example
+
+```js
+const feFloodElement = document.querySelector("feFlood");
+const filterName = feFloodElement.result;
+console.log(filterName.baseVa); // the filter's assigned name
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{domxref("SVGFEFloodElement.in1")}}
+- {{cssxref("custom-ident")}} data type- [SVG filter tutorial](/en-US/docs/Web/SVG/Tutorial/SVG_Filters_Tutorial)
+- CSS {{cssxref("blend-mode")}} data type
+- CSS {{cssxref("mix-blend-mode")}} property
diff --git a/files/en-us/web/api/svgfefloodelement/width/index.md b/files/en-us/web/api/svgfefloodelement/width/index.md
new file mode 100644
index 000000000000000..d5a079a6e13c514
--- /dev/null
+++ b/files/en-us/web/api/svgfefloodelement/width/index.md
@@ -0,0 +1,39 @@
+---
+title: "SVGFEFloodElement: width property"
+short-title: width
+slug: Web/API/SVGFEFloodElement/width
+page-type: web-api-instance-property
+browser-compat: api.SVGFEFloodElement.width
+---
+
+{{APIRef("SVG")}}
+
+The **`width`** read-only property of the {{domxref("SVGFEFloodElement")}} interface describes the horizontal size of an SVG filter primitive as a {{domxref("SVGAnimatedLength")}}.
+
+It reflects the {{SVGAttr("width")}} attribute of the {{SVGElement("feFlood")}} element, which fills an SVG filter subregion with the color and opacity defined by {{SVGAttr("flood-color")}} and {{SVGAttr("flood-opacity")}}. The attribute is a [`<length>`](/en-US/docs/Web/SVG/Content_type#length) or a [`<percentage>`](/en-US/docs/Web/SVG/Content_type#percentage) relative to the width of the filter region. The default value is `100%`. The property value is a length in user coordinate system units.
+
+## Value
+
+An {{domxref("SVGAnimatedLength")}}.
+
+## Example
+
+```js
+const feFlood = document.querySelector("feFlood");
+const horizontalSize = feFlood.width;
+console.log(horizontalSize.baseVal.value); // the `width` value
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{domxref("SVGFEFloodElement.height")}}- [SVG filter tutorial](/en-US/docs/Web/SVG/Tutorial/SVG_Filters_Tutorial)
+- CSS {{cssxref("blend-mode")}} data type
+- CSS {{cssxref("mix-blend-mode")}} property
diff --git a/files/en-us/web/api/svgfefloodelement/x/index.md b/files/en-us/web/api/svgfefloodelement/x/index.md
new file mode 100644
index 000000000000000..c673bb66201ef62
--- /dev/null
+++ b/files/en-us/web/api/svgfefloodelement/x/index.md
@@ -0,0 +1,39 @@
+---
+title: "SVGFEFloodElement: x property"
+short-title: x
+slug: Web/API/SVGFEFloodElement/x
+page-type: web-api-instance-property
+browser-compat: api.SVGFEFloodElement.x
+---
+
+{{APIRef("SVG")}}
+
+The **`x`** read-only property of the {{domxref("SVGFEFloodElement")}} interface describes the horizontal coordinate of the position of an SVG filter primitive as a {{domxref("SVGAnimatedLength")}}.
+
+It reflects the {{SVGAttr("x")}} attribute of the {{SVGElement("feFlood")}} element, which fills an SVG filter subregion with the color and opacity defined by {{SVGAttr("flood-color")}} and {{SVGAttr("flood-opacity")}}. The attribute is a [`<length>`](/en-US/docs/Web/SVG/Content_type#length) or [`<percentage>`](/en-US/docs/Web/SVG/Content_type#percentage). The `<coordinate>` is a length in the user coordinate system that is the given distance from the origin of the user coordinate system along the x-axis. If the `x` attribute is a percent value, the property value is relative to the width of the filter region in user coordinate system units. The default value is `0`.
+
+## Value
+
+An {{domxref("SVGAnimatedLength")}}.
+
+## Example
+
+```js
+const feFlood = document.querySelector("feFlood");
+const leftPosition = feFlood.x;
+console.log(leftPosition.baseVal.value); // the `x` value
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{domxref("SVGFEFloodElement.y")}}- [SVG filter tutorial](/en-US/docs/Web/SVG/Tutorial/SVG_Filters_Tutorial)
+- CSS {{cssxref("blend-mode")}} data type
+- CSS {{cssxref("mix-blend-mode")}} property
diff --git a/files/en-us/web/api/svgfefloodelement/y/index.md b/files/en-us/web/api/svgfefloodelement/y/index.md
new file mode 100644
index 000000000000000..87575c7c87fa047
--- /dev/null
+++ b/files/en-us/web/api/svgfefloodelement/y/index.md
@@ -0,0 +1,39 @@
+---
+title: "SVGFEFloodElement: y property"
+short-title: "y"
+slug: Web/API/SVGFEFloodElement/y
+page-type: web-api-instance-property
+browser-compat: api.SVGFEFloodElement.y
+---
+
+{{APIRef("SVG")}}
+
+The **`y`** read-only property of the {{domxref("SVGFEFloodElement")}} interface describes the vertical coordinate of the position of an SVG filter primitive as a {{domxref("SVGAnimatedLength")}}.
+
+It reflects the {{SVGAttr("y")}} attribute of the {{SVGElement("feFlood")}} element, which fills an SVG filter subregion with the color and opacity defined by {{SVGAttr("flood-color")}} and {{SVGAttr("flood-opacity")}}. The attribute is a [`<length>`](/en-US/docs/Web/SVG/Content_type#length) or [`<percentage>`](/en-US/docs/Web/SVG/Content_type#percentage). The `<coordinate>` is a length in the user coordinate system that is the given distance from the origin of the filter along the y-axis. If the `y` attribute is a percent value, the property value is relative to the height of the filter region in user coordinate system units. The default value is `0`.
+
+## Value
+
+An {{domxref("SVGAnimatedLength")}}.
+
+## Example
+
+```js
+const feFlood = document.querySelector("feFlood");
+const topPosition = feFlood.y;
+console.log(topPosition.baseVal.value); // the `y` value
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{domxref("SVGFEFloodElement.x")}}- [SVG filter tutorial](/en-US/docs/Web/SVG/Tutorial/SVG_Filters_Tutorial)
+- CSS {{cssxref("blend-mode")}} data type
+- CSS {{cssxref("mix-blend-mode")}} property
diff --git a/files/en-us/web/api/svgfegaussianblurelement/height/index.md b/files/en-us/web/api/svgfegaussianblurelement/height/index.md
new file mode 100644
index 000000000000000..dc2abaeb028750b
--- /dev/null
+++ b/files/en-us/web/api/svgfegaussianblurelement/height/index.md
@@ -0,0 +1,41 @@
+---
+title: "SVGFEGaussianBlurElement: height property"
+short-title: height
+slug: Web/API/SVGFEGaussianBlurElement/height
+page-type: web-api-instance-property
+browser-compat: api.SVGFEGaussianBlurElement.height
+---
+
+{{APIRef("SVG")}}
+
+The **`height`** read-only property of the {{domxref("SVGFEGaussianBlurElement")}} interface describes the vertical size of an SVG filter primitive as a {{domxref("SVGAnimatedLength")}}.
+
+It reflects the {{SVGAttr("height")}} attribute of the {{SVGElement("feGaussianBlur")}} element, which blurs an input image. The attribute is a [`<length>`](/en-US/docs/Web/SVG/Content_type#length) or a [`<percentage>`](/en-US/docs/Web/SVG/Content_type#percentage) relative to the height of the filter region. The default value is `100%`. The property value is a length in user coordinate system units.
+
+## Value
+
+An {{domxref("SVGAnimatedLength")}}.
+
+## Example
+
+```js
+const feGaussianBlur = document.querySelector("feGaussianBlur");
+const verticalSize = feGaussianBlur.height;
+console.log(verticalSize.baseVal.value); // the `height` value
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{domxref("SVGFEGaussianBlurElement.width")}}
+- [SVG filter tutorial](/en-US/docs/Web/SVG/Tutorial/SVG_Filters_Tutorial)
+- CSS {{cssxref("blend-mode")}} data type
+- CSS {{cssxref("filter-function/blur", "blur()")}} function
+- [CSS filter effects](/en-US/docs/Web/CSS/CSS_filter_effects) module- CSS {{cssxref("mix-blend-mode")}} property
diff --git a/files/en-us/web/api/svgfegaussianblurelement/result/index.md b/files/en-us/web/api/svgfegaussianblurelement/result/index.md
new file mode 100644
index 000000000000000..3d01fcf8e81b44b
--- /dev/null
+++ b/files/en-us/web/api/svgfegaussianblurelement/result/index.md
@@ -0,0 +1,44 @@
+---
+title: "SVGFEGaussianBlurElement: result property"
+short-title: result
+slug: Web/API/SVGFEGaussianBlurElement/result
+page-type: web-api-instance-property
+browser-compat: api.SVGFEGaussianBlurElement.result
+---
+
+{{APIRef("SVG")}}
+
+The **`result`** read-only property of the {{domxref("SVGFEGaussianBlurElement")}} interface describes the assigned name of an SVG filter primitive as a {{domxref("SVGAnimatedString")}}.
+
+It reflects the {{SVGAttr("result")}} attribute of the {{SVGElement("feGaussianBlur")}} element, which blurs an input image. The attribute value is a {{cssxref("custom-ident")}}. If supplied, then graphics that result from processing this filter primitive can be referenced by an {{SVGAttr("in")}} attribute on a subsequent filter primitive within the same {{SVGElement("filter")}} element.
+
+If no `result` attribute is defined, the filter's `result.baseVal` and `result.animVal` are empty strings, and the output of the `<feGaussianBlur>` filter will only be available for re-use as the implicit input into the next filter primitive if that filter primitive provides no value for its `in` attribute.
+
+## Value
+
+An {{domxref("SVGAnimatedString")}}.
+
+## Example
+
+```js
+const feGaussianBlurElement = document.querySelector("feGaussianBlur");
+const filterName = feGaussianBlurElement.result;
+console.log(filterName.baseVal); // the filter's assigned name
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{domxref("SVGFEGaussianBlurElement.in1")}}
+- {{cssxref("custom-ident")}} data type
+- [SVG filter tutorial](/en-US/docs/Web/SVG/Tutorial/SVG_Filters_Tutorial)
+- CSS {{cssxref("blend-mode")}} data type
+- CSS {{cssxref("filter-function/blur", "blur()")}} function
+- [CSS filter effects](/en-US/docs/Web/CSS/CSS_filter_effects) module- CSS {{cssxref("mix-blend-mode")}} property
diff --git a/files/en-us/web/api/svgfegaussianblurelement/width/index.md b/files/en-us/web/api/svgfegaussianblurelement/width/index.md
new file mode 100644
index 000000000000000..0fac3976f3fc340
--- /dev/null
+++ b/files/en-us/web/api/svgfegaussianblurelement/width/index.md
@@ -0,0 +1,41 @@
+---
+title: "SVGFEGaussianBlurElement: width property"
+short-title: width
+slug: Web/API/SVGFEGaussianBlurElement/width
+page-type: web-api-instance-property
+browser-compat: api.SVGFEGaussianBlurElement.width
+---
+
+{{APIRef("SVG")}}
+
+The **`width`** read-only property of the {{domxref("SVGFEGaussianBlurElement")}} interface describes the horizontal size of an SVG filter primitive as a {{domxref("SVGAnimatedLength")}}.
+
+It reflects the {{SVGAttr("width")}} attribute of the {{SVGElement("feGaussianBlur")}} element, which blurs an input image. The attribute is a [`<length>`](/en-US/docs/Web/SVG/Content_type#length) or a [`<percentage>`](/en-US/docs/Web/SVG/Content_type#percentage) relative to the width of the filter region. The default value is `100%`. The property value is a length in user coordinate system units.
+
+## Value
+
+An {{domxref("SVGAnimatedLength")}}.
+
+## Example
+
+```js
+const feGaussianBlur = document.querySelector("feGaussianBlur");
+const horizontalSize = feGaussianBlur.width;
+console.log(horizontalSize.baseVal.value); // the `width` value
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{domxref("SVGFEGaussianBlurElement.height")}}
+- [SVG filter tutorial](/en-US/docs/Web/SVG/Tutorial/SVG_Filters_Tutorial)
+- CSS {{cssxref("blend-mode")}} data type
+- CSS {{cssxref("filter-function/blur", "blur()")}} function
+- [CSS filter effects](/en-US/docs/Web/CSS/CSS_filter_effects) module- CSS {{cssxref("mix-blend-mode")}} property
diff --git a/files/en-us/web/api/svgfegaussianblurelement/x/index.md b/files/en-us/web/api/svgfegaussianblurelement/x/index.md
new file mode 100644
index 000000000000000..dc482de3e9ecfdf
--- /dev/null
+++ b/files/en-us/web/api/svgfegaussianblurelement/x/index.md
@@ -0,0 +1,41 @@
+---
+title: "SVGFEGaussianBlurElement: x property"
+short-title: x
+slug: Web/API/SVGFEGaussianBlurElement/x
+page-type: web-api-instance-property
+browser-compat: api.SVGFEGaussianBlurElement.x
+---
+
+{{APIRef("SVG")}}
+
+The **`x`** read-only property of the {{domxref("SVGFEGaussianBlurElement")}} interface describes the horizontal coordinate of the position of an SVG filter primitive as a {{domxref("SVGAnimatedLength")}}.
+
+It reflects the {{SVGAttr("x")}} attribute of the {{SVGElement("feGaussianBlur")}} element, which blurs an input image. The attribute is a [`<length>`](/en-US/docs/Web/SVG/Content_type#length) or [`<percentage>`](/en-US/docs/Web/SVG/Content_type#percentage). The `<coordinate>` is a length in the user coordinate system that is the given distance from the origin of the user coordinate system along the x-axis. If the `x` attribute is a percent value, the property value is relative to the width of the filter region in user coordinate system units. The default value is `0`.
+
+## Value
+
+An {{domxref("SVGAnimatedLength")}}.
+
+## Example
+
+```js
+const feGaussianBlur = document.querySelector("feGaussianBlur");
+const leftPosition = feGaussianBlur.x;
+console.log(leftPosition.baseVal.value); // the `x` value
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{domxref("SVGFEGaussianBlurElement.y")}}
+- [SVG filter tutorial](/en-US/docs/Web/SVG/Tutorial/SVG_Filters_Tutorial)
+- CSS {{cssxref("blend-mode")}} data type
+- CSS {{cssxref("filter-function/blur", "blur()")}} function
+- [CSS filter effects](/en-US/docs/Web/CSS/CSS_filter_effects) module- CSS {{cssxref("mix-blend-mode")}} property
diff --git a/files/en-us/web/api/svgfegaussianblurelement/y/index.md b/files/en-us/web/api/svgfegaussianblurelement/y/index.md
new file mode 100644
index 000000000000000..08b33a566fe3569
--- /dev/null
+++ b/files/en-us/web/api/svgfegaussianblurelement/y/index.md
@@ -0,0 +1,41 @@
+---
+title: "SVGFEGaussianBlurElement: y property"
+short-title: "y"
+slug: Web/API/SVGFEGaussianBlurElement/y
+page-type: web-api-instance-property
+browser-compat: api.SVGFEGaussianBlurElement.y
+---
+
+{{APIRef("SVG")}}
+
+The **`y`** read-only property of the {{domxref("SVGFEGaussianBlurElement")}} interface describes the vertical coordinate of the position of an SVG filter primitive as a {{domxref("SVGAnimatedLength")}}.
+
+It reflects the {{SVGAttr("y")}} attribute of the {{SVGElement("feGaussianBlur")}} element, which blurs an input image. The attribute is a [`<length>`](/en-US/docs/Web/SVG/Content_type#length) or [`<percentage>`](/en-US/docs/Web/SVG/Content_type#percentage). The `<coordinate>` is a length in the user coordinate system that is the given distance from the origin of the filter along the y-axis. If the `y` attribute is a percent value, the property value is relative to the height of the filter region in user coordinate system units. The default value is `0`.
+
+## Value
+
+An {{domxref("SVGAnimatedLength")}}.
+
+## Example
+
+```js
+const feGaussianBlur = document.querySelector("feGaussianBlur");
+const topPosition = feGaussianBlur.y;
+console.log(topPosition.baseVal.value); // the `y` value
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{domxref("SVGFEGaussianBlurElement.x")}}
+- [SVG filter tutorial](/en-US/docs/Web/SVG/Tutorial/SVG_Filters_Tutorial)
+- CSS {{cssxref("blend-mode")}} data type
+- CSS {{cssxref("filter-function/blur", "blur()")}} function
+- [CSS filter effects](/en-US/docs/Web/CSS/CSS_filter_effects) module- CSS {{cssxref("mix-blend-mode")}} property
diff --git a/files/en-us/web/api/svgfemergeelement/height/index.md b/files/en-us/web/api/svgfemergeelement/height/index.md
new file mode 100644
index 000000000000000..37550aa607ed393
--- /dev/null
+++ b/files/en-us/web/api/svgfemergeelement/height/index.md
@@ -0,0 +1,37 @@
+---
+title: "SVGFEMergeElement: height property"
+short-title: height
+slug: Web/API/SVGFEMergeElement/height
+page-type: web-api-instance-property
+browser-compat: api.SVGFEMergeElement.height
+---
+
+{{APIRef("SVG")}}
+
+The **`height`** read-only property of the {{domxref("SVGFEMergeElement")}} interface describes the vertical size of an SVG filter primitive as a {{domxref("SVGAnimatedLength")}}.
+
+It reflects the {{SVGAttr("height")}} attribute of the {{SVGElement("feMerge")}} element. The attribute is a [`<length>`](/en-US/docs/Web/SVG/Content_type#length) or a [`<percentage>`](/en-US/docs/Web/SVG/Content_type#percentage) relative to the height of the filter region. The default value is `100%`. The property value is a length in user coordinate system units.
+
+## Value
+
+An {{domxref("SVGAnimatedLength")}}.
+
+## Example
+
+```js
+const feMerge = document.querySelector("feMerge");
+const verticalSize = feMerge.height;
+console.log(verticalSize.baseVal.value); // the `height` value
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{domxref("SVGFEMergeElement.width")}}
diff --git a/files/en-us/web/api/svgfemergeelement/result/index.md b/files/en-us/web/api/svgfemergeelement/result/index.md
new file mode 100644
index 000000000000000..1fc990946a3d5f4
--- /dev/null
+++ b/files/en-us/web/api/svgfemergeelement/result/index.md
@@ -0,0 +1,40 @@
+---
+title: "SVGFEMergeElement: result property"
+short-title: result
+slug: Web/API/SVGFEMergeElement/result
+page-type: web-api-instance-property
+browser-compat: api.SVGFEMergeElement.result
+---
+
+{{APIRef("SVG")}}
+
+The **`result`** read-only property of the {{domxref("SVGFEMergeElement")}} interface describes the assigned name of an SVG filter primitive as a {{domxref("SVGAnimatedString")}}.
+
+It reflects the {{SVGAttr("result")}} attribute of the {{SVGElement("feMerge")}} element. The attribute value is a {{cssxref("custom-ident")}}. If supplied, then graphics that result from processing this filter primitive can be referenced by an {{SVGAttr("in")}} attribute on a subsequent filter primitive within the same {{SVGElement("filter")}} element.
+
+If no `result` attribute is defined, the filter's `result.baseVal` and `result.animVal` are empty strings, and the output of the `<feMerge>` filter will only be available for re-use as the implicit input into the next filter primitive if that filter primitive provides no value for its `in` attribute.
+
+## Value
+
+An {{domxref("SVGAnimatedString")}}.
+
+## Example
+
+```js
+const feMergeElement = document.querySelector("feMerge");
+const filterName = feMergeElement.result;
+console.log(filterName.baseVal); // the filter's assigned name
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{domxref("SVGFEMergeNodeElement.in1")}}
+- {{cssxref("custom-ident")}} data type
diff --git a/files/en-us/web/api/svgfemergeelement/width/index.md b/files/en-us/web/api/svgfemergeelement/width/index.md
new file mode 100644
index 000000000000000..576b60896fc5807
--- /dev/null
+++ b/files/en-us/web/api/svgfemergeelement/width/index.md
@@ -0,0 +1,37 @@
+---
+title: "SVGFEMergeElement: width property"
+short-title: width
+slug: Web/API/SVGFEMergeElement/width
+page-type: web-api-instance-property
+browser-compat: api.SVGFEMergeElement.width
+---
+
+{{APIRef("SVG")}}
+
+The **`width`** read-only property of the {{domxref("SVGFEMergeElement")}} interface describes the horizontal size of an SVG filter primitive as a {{domxref("SVGAnimatedLength")}}.
+
+It reflects the {{SVGAttr("width")}} attribute of the {{SVGElement("feMerge")}} element. The attribute is a [`<length>`](/en-US/docs/Web/SVG/Content_type#length) or a [`<percentage>`](/en-US/docs/Web/SVG/Content_type#percentage) relative to the width of the filter region. The default value is `100%`. The property value is a length in user coordinate system units.
+
+## Value
+
+An {{domxref("SVGAnimatedLength")}}.
+
+## Example
+
+```js
+const feMerge = document.querySelector("feMerge");
+const horizontalSize = feMerge.width;
+console.log(horizontalSize.baseVal.value); // the `width` value
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{domxref("SVGFEMergeElement.height")}}
diff --git a/files/en-us/web/api/svgfemergeelement/x/index.md b/files/en-us/web/api/svgfemergeelement/x/index.md
new file mode 100644
index 000000000000000..3e6ab2a710ee096
--- /dev/null
+++ b/files/en-us/web/api/svgfemergeelement/x/index.md
@@ -0,0 +1,37 @@
+---
+title: "SVGFEMergeElement: x property"
+short-title: x
+slug: Web/API/SVGFEMergeElement/x
+page-type: web-api-instance-property
+browser-compat: api.SVGFEMergeElement.x
+---
+
+{{APIRef("SVG")}}
+
+The **`x`** read-only property of the {{domxref("SVGFEMergeElement")}} interface describes the horizontal coordinate of the position of an SVG filter primitive as a {{domxref("SVGAnimatedLength")}}.
+
+It reflects the {{SVGAttr("x")}} attribute of the {{SVGElement("feMerge")}} element. The attribute is a [`<length>`](/en-US/docs/Web/SVG/Content_type#length) or [`<percentage>`](/en-US/docs/Web/SVG/Content_type#percentage). The `<coordinate>` is a length in the user coordinate system that is the given distance from the origin of the user coordinate system along the x-axis. If the `x` attribute is a percent value, the property value is relative to the width of the filter region in user coordinate system units. The default value is `0`.
+
+## Value
+
+An {{domxref("SVGAnimatedLength")}}.
+
+## Example
+
+```js
+const feMerge = document.querySelector("feMerge");
+const leftPosition = feMerge.x;
+console.log(leftPosition.baseVal.value); // the `x` value
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{domxref("SVGFEMergeElement.y")}}
diff --git a/files/en-us/web/api/svgfemergeelement/y/index.md b/files/en-us/web/api/svgfemergeelement/y/index.md
new file mode 100644
index 000000000000000..8741bc723db9661
--- /dev/null
+++ b/files/en-us/web/api/svgfemergeelement/y/index.md
@@ -0,0 +1,37 @@
+---
+title: "SVGFEMergeElement: y property"
+short-title: "y"
+slug: Web/API/SVGFEMergeElement/y
+page-type: web-api-instance-property
+browser-compat: api.SVGFEMergeElement.y
+---
+
+{{APIRef("SVG")}}
+
+The **`y`** read-only property of the {{domxref("SVGFEMergeElement")}} interface describes the vertical coordinate of the position of an SVG filter primitive as a {{domxref("SVGAnimatedLength")}}.
+
+It reflects the {{SVGAttr("y")}} attribute of the {{SVGElement("feMerge")}} element. The attribute is a [`<length>`](/en-US/docs/Web/SVG/Content_type#length) or [`<percentage>`](/en-US/docs/Web/SVG/Content_type#percentage). The `<coordinate>` is a length in the user coordinate system that is the given distance from the origin of the filter along the y-axis. If the `y` attribute is a percent value, the property value is a relative to the height of the filter region in user coordinate system units. The default value is `0`.
+
+## Value
+
+An {{domxref("SVGAnimatedLength")}}.
+
+## Example
+
+```js
+const feMerge = document.querySelector("feMerge");
+const topPosition = feMerge.y;
+console.log(topPosition.baseVal.value); // the `y` value
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{domxref("SVGFEMergeElement.x")}}
diff --git a/files/en-us/web/api/svgfepointlightelement/x/index.md b/files/en-us/web/api/svgfepointlightelement/x/index.md
new file mode 100644
index 000000000000000..34c71943e856892
--- /dev/null
+++ b/files/en-us/web/api/svgfepointlightelement/x/index.md
@@ -0,0 +1,40 @@
+---
+title: "SVGFEPointLightElement: x property"
+short-title: x
+slug: Web/API/SVGFEPointLightElement/x
+page-type: web-api-instance-property
+browser-compat: api.SVGFEPointLightElement.x
+---
+
+{{APIRef("SVG")}}
+
+The **`x`** read-only property of the {{domxref("SVGFEPointLightElement")}} interface describes the horizontal coordinate of the position of an SVG filter primitive as a {{domxref("SVGAnimatedNumber")}}.
+
+It reflects the {{SVGAttr("x")}} attribute of the {{SVGElement("fePointLight")}} element, which can be used to define the light source in a point light effect. The attribute is a [`<number>`](/en-US/docs/Web/SVG/Content_type#number). The default value is `0`.
+
+## Value
+
+An {{domxref("SVGAnimatedNumber")}}.
+
+## Example
+
+```js
+const fePointLight = document.querySelector("fePointLight");
+const leftPosition = fePointLight.x;
+console.log(leftPosition.baseVal.value); // the `x` value
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{domxref("SVGFEPointLightElement.y")}}
+- {{domxref("SVGFEPointLightElement.z")}}
+- {{domxref("SVGFEDistantLightElement")}}
+- {{domxref("SVGFESpotLightElement")}}
diff --git a/files/en-us/web/api/svgfepointlightelement/y/index.md b/files/en-us/web/api/svgfepointlightelement/y/index.md
new file mode 100644
index 000000000000000..e789e8820eaeecf
--- /dev/null
+++ b/files/en-us/web/api/svgfepointlightelement/y/index.md
@@ -0,0 +1,40 @@
+---
+title: "SVGFEPointLightElement: y property"
+short-title: "y"
+slug: Web/API/SVGFEPointLightElement/y
+page-type: web-api-instance-property
+browser-compat: api.SVGFEPointLightElement.y
+---
+
+{{APIRef("SVG")}}
+
+The **`y`** read-only property of the {{domxref("SVGFEPointLightElement")}} interface describes the vertical coordinate of the position of an SVG filter primitive as a {{domxref("SVGAnimatedNumber")}}.
+
+It reflects the {{SVGAttr("y")}} attribute of the {{SVGElement("fePointLight")}} element, which can be used to define the light source in a point light effect. The attribute is a [`<number>`](/en-US/docs/Web/SVG/Content_type#number). The default value is `0`.
+
+## Value
+
+An {{domxref("SVGAnimatedNumber")}}.
+
+## Example
+
+```js
+const fePointLight = document.querySelector("fePointLight");
+const topPosition = fePointLight.y;
+console.log(topPosition.baseVal.value); // the `y` value
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{domxref("SVGFEPointLightElement.x")}}
+- {{domxref("SVGFEPointLightElement.z")}}
+- {{domxref("SVGFEDistantLightElement")}}
+- {{domxref("SVGFESpotLightElement")}}
diff --git a/files/en-us/web/api/svgfepointlightelement/z/index.md b/files/en-us/web/api/svgfepointlightelement/z/index.md
new file mode 100644
index 000000000000000..4c3700613e2ba9c
--- /dev/null
+++ b/files/en-us/web/api/svgfepointlightelement/z/index.md
@@ -0,0 +1,40 @@
+---
+title: "SVGFEPointLightElement: z property"
+short-title: z
+slug: Web/API/SVGFEPointLightElement/z
+page-type: web-api-instance-property
+browser-compat: api.SVGFEPointLightElement.z
+---
+
+{{APIRef("SVG")}}
+
+The **`z`** read-only property of the {{domxref("SVGFEPointLightElement")}} interface describes the z-axis value of the position of an SVG filter primitive as a {{domxref("SVGAnimatedNumber")}}. A positive Z-axis comes out towards the person viewing the content.
+
+It reflects the {{SVGAttr("z")}} attribute of the {{SVGElement("fePointLight")}} element, which can be used to define the light source in a point light effect. The attribute is a [`<number>`](/en-US/docs/Web/SVG/Content_type#number). The default value is `0`.
+
+## Value
+
+An {{domxref("SVGAnimatedNumber")}}.
+
+## Example
+
+```js
+const fePointLight = document.querySelector("fePointLight");
+const zVal = fePointLight.z;
+console.log(zVal.baseVal.value); // the `z` value
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{domxref("SVGFEPointLightElement.x")}}
+- {{domxref("SVGFEPointLightElement.y")}}
+- {{domxref("SVGFEDistantLightElement")}}
+- {{domxref("SVGFESpotLightElement")}}
diff --git a/files/en-us/web/api/svgfespotlightelement/x/index.md b/files/en-us/web/api/svgfespotlightelement/x/index.md
new file mode 100644
index 000000000000000..ed1f3f0e2d892ec
--- /dev/null
+++ b/files/en-us/web/api/svgfespotlightelement/x/index.md
@@ -0,0 +1,40 @@
+---
+title: "SVGFESpotLightElement: x property"
+short-title: x
+slug: Web/API/SVGFESpotLightElement/x
+page-type: web-api-instance-property
+browser-compat: api.SVGFESpotLightElement.x
+---
+
+{{APIRef("SVG")}}
+
+The **`x`** read-only property of the {{domxref("SVGFESpotLightElement")}} interface describes the horizontal coordinate of the position of an SVG filter primitive as a {{domxref("SVGAnimatedNumber")}}.
+
+It reflects the {{SVGAttr("x")}} attribute of the {{SVGElement("feSpotLight")}} element., which can be used to define the light source in a spotlight effect. The attribute is a [`<number>`](/en-US/docs/Web/SVG/Content_type#number). The default value is `0`.
+
+## Value
+
+An {{domxref("SVGAnimatedNumber")}}.
+
+## Example
+
+```js
+const feSpotLight = document.querySelector("feSpotLight");
+const leftPosition = feSpotLight.x;
+console.log(leftPosition.baseVal.value); // the `x` value
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{domxref("SVGFESpotLightElement.y")}}
+- {{domxref("SVGFESpotLightElement.z")}}
+- {{domxref("SVGFEDistantLightElement")}}
+- {{domxref("SVGFEPointLightElement")}}
diff --git a/files/en-us/web/api/svgfespotlightelement/y/index.md b/files/en-us/web/api/svgfespotlightelement/y/index.md
new file mode 100644
index 000000000000000..75f931c50c4cff8
--- /dev/null
+++ b/files/en-us/web/api/svgfespotlightelement/y/index.md
@@ -0,0 +1,40 @@
+---
+title: "SVGFESpotLightElement: y property"
+short-title: "y"
+slug: Web/API/SVGFESpotLightElement/y
+page-type: web-api-instance-property
+browser-compat: api.SVGFESpotLightElement.y
+---
+
+{{APIRef("SVG")}}
+
+The **`y`** read-only property of the {{domxref("SVGFESpotLightElement")}} interface describes the vertical coordinate of the position of an SVG filter primitive as a {{domxref("SVGAnimatedNumber")}}.
+
+It reflects the {{SVGAttr("y")}} attribute of the {{SVGElement("feSpotLight")}} element., which can be used to define the light source in a spotlight effect. The attribute is a [`<number>`](/en-US/docs/Web/SVG/Content_type#number). The default value is `0`.
+
+## Value
+
+An {{domxref("SVGAnimatedNumber")}}.
+
+## Example
+
+```js
+const feSpotLight = document.querySelector("feSpotLight");
+const topPosition = feSpotLight.y;
+console.log(topPosition.baseVal.value); // the `y` value
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{domxref("SVGFESpotLightElement.x")}}
+- {{domxref("SVGFESpotLightElement.z")}}
+- {{domxref("SVGFEDistantLightElement")}}
+- {{domxref("SVGFEPointLightElement")}}
diff --git a/files/en-us/web/api/svgfespotlightelement/z/index.md b/files/en-us/web/api/svgfespotlightelement/z/index.md
new file mode 100644
index 000000000000000..e9bce8fdade293f
--- /dev/null
+++ b/files/en-us/web/api/svgfespotlightelement/z/index.md
@@ -0,0 +1,40 @@
+---
+title: "SVGFESpotLightElement: z property"
+short-title: z
+slug: Web/API/SVGFESpotLightElement/z
+page-type: web-api-instance-property
+browser-compat: api.SVGFESpotLightElement.z
+---
+
+{{APIRef("SVG")}}
+
+The **`z`** read-only property of the {{domxref("SVGFESpotLightElement")}} interface describes the z-axis value of the position of an SVG filter primitive as a {{domxref("SVGAnimatedNumber")}}. A positive Z-axis comes out towards the person viewing the content.
+
+It reflects the {{SVGAttr("z")}} attribute of the {{SVGElement("feSpotLight")}} element, which can be used to define the light source in a spotlight effect. The attribute is a [`<number>`](/en-US/docs/Web/SVG/Content_type#number). The default value is `0`.
+
+## Value
+
+An {{domxref("SVGAnimatedNumber")}}.
+
+## Example
+
+```js
+const feSpotLight = document.querySelector("feSpotLight");
+const zVal = feSpotLight.z;
+console.log(zVal.baseVal.value); // the `z` value
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{domxref("SVGFESpotLightElement.x")}}
+- {{domxref("SVGFESpotLightElement.y")}}
+- {{domxref("SVGFEDistantLightElement")}}
+- {{domxref("SVGFEPointLightElement")}}
diff --git a/files/en-us/web/api/url/pathname/index.md b/files/en-us/web/api/url/pathname/index.md
index 20aa16660136e83..9dfef11f5d1f85f 100644
--- a/files/en-us/web/api/url/pathname/index.md
+++ b/files/en-us/web/api/url/pathname/index.md
@@ -11,7 +11,7 @@ browser-compat: api.URL.pathname
 The **`pathname`** property of the {{domxref("URL")}} interface represents a location in a hierarchical structure. It is a string constructed from a list of path segments, each of which is prefixed by a `/` character.
 
 HTTPS, HTTP, or other URLs with [hierarchical schemes](https://www.rfc-editor.org/rfc/rfc3986#section-1.2.3) (which the URL standard calls "[special schemes](https://url.spec.whatwg.org/#special-scheme)") always have at least one (invisible) path segment: the empty string.
-The `pathname` value for such URLs will therefore always have a least one `/` character.
+The `pathname` value for such URLs will therefore always have at least one `/` character.
 
 For non-hierarchical schemes, if the URL has no path segments, the value of its `pathname` property will be the empty string.
 
diff --git a/files/en-us/web/api/webgl_api/tutorial/using_textures_in_webgl/index.md b/files/en-us/web/api/webgl_api/tutorial/using_textures_in_webgl/index.md
index f02b8f03569cac6..914bf866eb2a4ad 100644
--- a/files/en-us/web/api/webgl_api/tutorial/using_textures_in_webgl/index.md
+++ b/files/en-us/web/api/webgl_api/tutorial/using_textures_in_webgl/index.md
@@ -221,7 +221,7 @@ const vsSource = `
   `;
 ```
 
-The key change here is that instead of fetching the vertex color, we're fetching the texture coordinates and passing them to the vertex shader; this will indicate the location within the texture corresponding to the vertex.
+The key change here is that instead of fetching the vertex color, we're fetching the texture coordinates and passing them to the fragment shader; this will indicate the location within the texture corresponding to the vertex.
 
 ### The fragment shader
 
diff --git a/files/en-us/web/api/webtransport/createunidirectionalstream/index.md b/files/en-us/web/api/webtransport/createunidirectionalstream/index.md
index df7c280f45ffc64..0d35caf10dab15e 100644
--- a/files/en-us/web/api/webtransport/createunidirectionalstream/index.md
+++ b/files/en-us/web/api/webtransport/createunidirectionalstream/index.md
@@ -59,7 +59,7 @@ async function writeData() {
   const stream = await transport.createUnidirectionalStream({
     sendOrder: "596996858",
   });
-  const writer = stream.writable.getWriter();
+  const writer = stream.getWriter();
   const data1 = new Uint8Array([65, 66, 67]);
   const data2 = new Uint8Array([68, 69, 70]);
   writer.write(data1);
@@ -80,7 +80,7 @@ You can also use {{domxref("WritableStreamDefaultWriter.abort()")}} to abruptly
 // ...
 
 const stream = await transport.createUnidirectionalStream();
-const writer = ws.getWriter();
+const writer = stream.getWriter();
 
 // ...
 
diff --git a/files/en-us/web/api/window/matchmedia/index.md b/files/en-us/web/api/window/matchmedia/index.md
index e68f396bb7af5e3..fe1d37972fa74d7 100644
--- a/files/en-us/web/api/window/matchmedia/index.md
+++ b/files/en-us/web/api/window/matchmedia/index.md
@@ -23,8 +23,11 @@ matchMedia(mediaQueryString)
 ### Parameters
 
 - `mediaQueryString`
+
   - : A string specifying the media query to parse into a {{domxref("MediaQueryList")}}.
 
+    Just like in CSS, any [media feature](/en-US/docs/Web/CSS/@media#media_features) must be wrapped in parentheses inside the expression. For example: `matchMedia("(max-width: 600px)")` works, whereas `matchMedia("max-width: 600px")` does not. Keywords for media types (`all`, `print`, `screen`) and logical operators (`and`, `or`, `not`, `only`) do not need to be wrapped in parentheses.
+
 ### Return value
 
 A new {{domxref("MediaQueryList")}} object for the media query. Use this object's
diff --git a/files/en-us/web/css/@font-face/index.md b/files/en-us/web/css/@font-face/index.md
index a2cc498998123a5..d1d430bd1c6e05a 100644
--- a/files/en-us/web/css/@font-face/index.md
+++ b/files/en-us/web/css/@font-face/index.md
@@ -31,23 +31,23 @@ The **`@font-face`** [CSS](/en-US/docs/Web/CSS) [at-rule](/en-US/docs/Web/CSS/At
 - {{cssxref("@font-face/font-display", "font-display")}}
   - : Determines how a font face is displayed based on whether and when it is downloaded and ready to use.
 - {{cssxref("@font-face/font-family", "font-family")}}
-  - : Specifies a name that will be used as the font face value for font properties.
+  - : Specifies a name that will be used as the font face value for font properties. A `font-family` name is required for the `@font-face` rule to be valid.
 - {{cssxref("@font-face/font-stretch", "font-stretch")}}
-  - : A {{cssxref("font-stretch")}} value. Accepts two values to specify a range that is supported by a font-face, for example `font-stretch: 50% 200%;`
+  - : A {{cssxref("font-stretch")}} value. Accepts two values to specify a range that is supported by a font face, for example `font-stretch: 50% 200%;`
 - {{cssxref("@font-face/font-style", "font-style")}}
-  - : A {{cssxref("font-style")}} value. Accepts two values to specify a range that is supported by a font-face, for example `font-style: oblique 20deg 50deg;`
+  - : A {{cssxref("font-style")}} value. Accepts two values to specify a range that is supported by a font face, for example `font-style: oblique 20deg 50deg;`
 - {{cssxref("@font-face/font-weight", "font-weight")}}
-  - : A {{cssxref("font-weight")}} value. Accepts two values to specify a range that is supported by a font-face, for example `font-weight: 100 400;`
+  - : A {{cssxref("font-weight")}} value. Accepts two values to specify a range that is supported by a font face, for example `font-weight: 100 400;`
 - {{cssxref("@font-face/font-feature-settings", "font-feature-settings")}}
   - : Allows control over advanced typographic features in OpenType fonts.
 - {{cssxref("@font-face/font-variation-settings", "font-variation-settings")}}
-  - : Allows low-level control over OpenType or TrueType font variations, by specifying the four letter axis names of the features to vary, along with their variation values.
+  - : Allows low-level control over OpenType or TrueType font variations, by specifying the four-letter axis names of the features to vary, along with their variation values.
 - {{cssxref("@font-face/line-gap-override", "line-gap-override")}}
   - : Defines the line gap metric for the font.
 - {{cssxref("@font-face/size-adjust", "size-adjust")}}
   - : Defines a multiplier for glyph outlines and metrics associated with this font. This makes it easier to harmonize the designs of various fonts when rendered at the same font size.
 - {{cssxref("@font-face/src", "src")}}
-  - : Specifies references to font resources including hints about the font format and technology. It is required for the @font-face rule to be valid.
+  - : Specifies references to font resources including hints about the font format and technology. A `src` is required for the `@font-face` rule to be valid.
 - {{cssxref("@font-face/unicode-range", "unicode-range")}}
   - : The range of Unicode code points to be used from the font.
 
@@ -58,9 +58,9 @@ It's common to use both `url()` and `local()` together, so that the user's insta
 If the `local()` function is provided, specifying a font name to look for on the user's device, and if the {{Glossary("user agent")}} finds a match, that local font is used. Otherwise, the font resource specified using the `url()` function is downloaded and used.
 
 Browsers attempt to load resources in their list declaration order, so usually `local()` should be written before `url()`. Both functions are optional, so a rule block containing only one or more `local()` without `url()` is possible.
-If a more specific fonts with `format()` or `tech()` values are desired, these should be listed _before_ versions that don't have these values, as the less-specific variant would otherwise be tried and used first.
+If more specific fonts with `format()` or `tech()` values are desired, these should be listed _before_ versions that don't have these values, as the less specific variant would otherwise be tried and used first.
 
-By allowing authors to provide their own fonts, `@font-face` makes it possible to design content without being limited to the so-called "web-safe" fonts (that is, the fonts which are so common that they're considered to be universally available). The ability to specify the name of a locally-installed font to look for and use makes it possible to customize the font beyond the basics while making it possible to do so without relying on an internet connection.
+By allowing authors to provide their own fonts, `@font-face` makes it possible to design content without being limited to the so-called "web-safe" fonts (that is, the fonts that are so common that they're considered to be universally available). The ability to specify the name of a locally-installed font to look for and use makes it possible to customize the font beyond the basics while making it possible to do so without relying on an internet connection.
 
 > [!NOTE]
 > Fallback strategies for loading fonts on older browsers are described in the [`src` descriptor page](/en-US/docs/Web/CSS/@font-face/src#specifying_fallbacks_for_older_browsers).
diff --git a/files/en-us/web/css/@view-transition/index.md b/files/en-us/web/css/@view-transition/index.md
index da57fa751b396bd..6ad0a66fef23bf1 100644
--- a/files/en-us/web/css/@view-transition/index.md
+++ b/files/en-us/web/css/@view-transition/index.md
@@ -49,7 +49,7 @@ The `@view-transition` at-rule is specified in the CSS for both your current and
 }
 ```
 
-In addition to the `@view-transition` at-rule, we define two {{cssxref("@keyframe")}} animations and use the {{cssxref("animation")}} shorthand property to apply those keyframe animations to the elements in the outbound ({{cssxref("::view-transition-old()")}}) and inbound ({{cssxref("::view-transition-new()")}}) pages that we want to animate.
+In addition to the `@view-transition` at-rule, we use the {{cssxref("@keyframes")}} at-rule to define two keyframe animations and use the {{cssxref("animation")}} shorthand property to apply those keyframe animations to the elements in the outbound ({{cssxref("::view-transition-old()")}}) and inbound ({{cssxref("::view-transition-new()")}}) pages that we want to animate.
 
 ```css
 /* Create a custom animation */
diff --git a/files/en-us/web/css/align-items/index.md b/files/en-us/web/css/align-items/index.md
index 93d41aa8fc95d42..55753464726b85b 100644
--- a/files/en-us/web/css/align-items/index.md
+++ b/files/en-us/web/css/align-items/index.md
@@ -55,7 +55,7 @@ align-items: unset;
     - In absolutely-positioned layouts, the keyword behaves like `start` on _replaced_ absolutely-positioned boxes, and as `stretch` on _all other_ absolutely-positioned boxes.
     - In static position of absolutely-positioned layouts, the keyword behaves as `stretch`.
     - For flex items, the keyword behaves as `stretch`.
-    - For grid items, this keyword leads to a behavior similar to the one of `stretch`, except for boxes with an {{glossary("aspect ratio")}} or an intrinsic sizes where it behaves like `start`.
+    - For grid items, this keyword leads to a behavior similar to the one of `stretch`, except for boxes with an {{glossary("aspect ratio")}} or an intrinsic size where it behaves like `start`.
     - The property doesn't apply to block-level boxes, and to table cells.
 
 - `center`
diff --git a/files/en-us/web/css/align-self/index.md b/files/en-us/web/css/align-self/index.md
index 56c1ab8081bface..0d06b47b3712891 100644
--- a/files/en-us/web/css/align-self/index.md
+++ b/files/en-us/web/css/align-self/index.md
@@ -60,7 +60,7 @@ align-self: unset;
     - In absolutely-positioned layouts, the keyword behaves like `start` on _replaced_ absolutely-positioned boxes, and as `stretch` on _all other_ absolutely-positioned boxes.
     - In static position of absolutely-positioned layouts, the keyword behaves as `stretch`.
     - For flex items, the keyword behaves as `stretch`.
-    - For grid items, this keyword leads to a behavior similar to the one of `stretch`, except for boxes with an {{glossary("aspect ratio")}} or an intrinsic sizes where it behaves like `start`.
+    - For grid items, this keyword leads to a behavior similar to the one of `stretch`, except for boxes with an {{glossary("aspect ratio")}} or an intrinsic size where it behaves like `start`.
     - The property doesn't apply to block-level boxes, and to table cells.
 
 - `self-start`
diff --git a/files/en-us/web/css/attr/index.md b/files/en-us/web/css/attr/index.md
index 7c1f4dca24fa130..f020515c40cc6d8 100644
--- a/files/en-us/web/css/attr/index.md
+++ b/files/en-us/web/css/attr/index.md
@@ -8,9 +8,9 @@ browser-compat: css.types.attr
 {{CSSRef}}
 
 > [!NOTE]
-> The `attr()` function can be used with any CSS property, but support for properties other than {{CSSxRef("content")}} is experimental, and support for the type-or-unit parameter is sparse.
+> The `attr()` function can be used with any CSS property, but support for properties other than {{CSSxRef("content")}} is experimental.
 
-The **`attr()`** [CSS](/en-US/docs/Web/CSS) [function](/en-US/docs/Web/CSS/CSS_Functions) is used to retrieve the value of an attribute of the selected element and use it in the stylesheet. It can also be used on [pseudo-elements](/en-US/docs/Web/CSS/Pseudo-elements), in which case the value of the attribute on the pseudo-element's originating element is returned.
+The **`attr()`** [CSS](/en-US/docs/Web/CSS) [function](/en-US/docs/Web/CSS/CSS_Functions) is used to retrieve the value of an attribute of the selected element and use it in a property value, similar to how the {{cssxref("var", "var()")}} function substitutes a custom property value. It can also be used with [pseudo-elements](/en-US/docs/Web/CSS/Pseudo-elements), in which case the attribute's value on the pseudo-element's originating element is returned.
 
 {{EmbedInteractiveExample("pages/tabbed/function-attr.html", "tabbed-shorter")}}
 
@@ -18,130 +18,170 @@ The **`attr()`** [CSS](/en-US/docs/Web/CSS) [function](/en-US/docs/Web/CSS/CSS_F
 
 ```css
 /* Basic usage */
-attr(data-count);
-attr(title);
+attr(data-count)
+attr(href)
 
 /* With type */
-attr(src url);
-attr(data-count number);
-attr(data-width px);
+attr(data-width px)
+attr(data-size rem)
+attr(data-name string)
+attr(id type(<custom-ident>))
+attr(data-count type(<number>))
+attr(data-size type(<length> | <percentage>))
 
 /* With fallback */
-attr(data-count number, 0);
-attr(src url, "");
-attr(data-width px, inherit);
-attr(data-something, "default");
+attr(data-count type(<number>), 0)
+attr(data-width px, inherit)
+attr(data-something, "default")
 ```
 
-### Values
+### Parameters
 
-- `attribute-name`
-  - : The name of an attribute on the HTML element referenced in the CSS.
-- `<type-or-unit>`
+The `attr()` function's syntax is as follows:
 
-  - : A keyword representing either the type of the attribute's value, or its unit, as in HTML some attributes have implicit units. If the use of `<type-or-unit>` as a value for the given attribute is invalid, the `attr()` expression will be invalid too. If omitted, it defaults to `string`. The list of valid values are:
+```plain
+attr(<attr-name> <attr-type>? , <fallback-value>?)
+```
 
-    - `string`
+The parameters are:
 
-      - : The attribute value is treated as a CSS {{CSSxRef("&lt;string&gt;")}}. It is NOT reparsed, and in particular the characters are used as-is instead of CSS escapes being turned into different characters.
+- `<attr-name>`
+  - : The attribute name whose value should be retrieved from the selected HTML element(s).
+- `<attr-type>`
 
-        Default value: an empty string.
+  - : Specifies how the attribute value is parsed into a CSS value. This can be the `string` keyword, a `type()` function, or a CSS dimension unit. When omitted, it defaults to `string`.
 
-    - `color`
+    - The `string` keyword parses the value into a CSS string.
 
-      - : The attribute value is parsed as a hash (3- or 6-value hash) or a keyword. It must be a valid CSS {{CSSxRef("&lt;string&gt;")}} value. Leading and trailing spaces are stripped.
+      ```css
+      attr(data-name string, "stranger")
+      ```
 
-        Default value: `currentcolor`.
+    - The `type()` function takes a `<syntax>` as its argument that specifies what [data type](/en-US/docs/Web/CSS/CSS_Types) to parse the value into. The `<syntax>` can be {{CSSxRef("&lt;angle&gt;")}}, {{CSSxRef("&lt;color&gt;")}}, {{CSSxRef("&lt;custom-ident&gt;")}}, {{CSSxRef("&lt;image&gt;")}}, {{CSSxRef("&lt;integer&gt;")}}, {{CSSxRef("&lt;length&gt;")}}, {{CSSxRef("&lt;length-percentage&gt;")}}, {{CSSxRef("&lt;number&gt;")}}, {{CSSxRef("&lt;percentage&gt;")}}, {{CSSxRef("&lt;resolution&gt;")}}, {{CSSxRef("&lt;string&gt;")}}, {{CSSxRef("&lt;time&gt;")}}, {{CSSxRef("&lt;transform-function&gt;")}}, or a combination thereof.
 
-    - `url`
+      ```css
+      attr(id type(<custom-ident>), none)
+      attr(data-count type(<number>), 0)
+      ```
 
-      - : The attribute value is parsed as a string that is used inside a CSS `url()` function.
-        Relative URL are resolved relatively to the original document, not relatively to the style sheet.
-        Leading and trailing spaces are stripped.
+      To accept multiple types, list all allowed `<syntax>`es in the `type()` function, separated by a `|`.
 
-        Default value: the URL `about:invalid` that points to a non-existent document with a generic error condition.
+      ```css
+      attr(data-size type(<length> | <percentage>), 0px)
+      ```
 
-    - `integer`
+      For [security reasons](#limitations_and_security) {{CSSxRef("&lt;url&gt;")}} is not allowed as a `<syntax>`.
 
-      - : The attribute value is parsed as a CSS {{CSSxRef("&lt;integer&gt;")}}. If it is not valid, that is not an integer or out of the range accepted by the CSS property, the default value is used.
-        Leading and trailing spaces are stripped.
+    - The `<attr-unit>` identifier specifies the unit a numeric value should have (if any). It can be the `%` character (percentage) or a [CSS distance unit](/en-US/docs/Web/CSS/CSS_Values_and_Units#distance_units) such as `px`, `rem`, `deg`, `s`, etc.
 
-        Default value: `0`, or, if `0` is not a valid value for the property, the property's minimum value.
+      ```css
+      attr(data-size rem)
+      attr(data-width px, inherit)
+      attr(data-rotation deg)
+      ```
 
-    - `number`
+- `<fallback-value>`
+  - : The value to be used if the specified attribute is missing or contains an invalid value.
 
-      - : The attribute value is parsed as a CSS {{CSSxRef("&lt;number&gt;")}}. If it is not valid, that is not a number or out of the range accepted by the CSS property, the default value is used.
-        Leading and trailing spaces are stripped.
+### Return value
 
-        Default value: `0`, or, if `0` is not a valid value for the property, the property's minimum value.
+The return value of `attr()` is the value of the HTML attribute whose name is `<attr-name>` parsed as the given `<attr-type>` or parsed as a CSS string.
 
-    - `length`
+When an `<attr-type>` is set, `attr()` will try to parse the attribute into that specified `<attr-type>` and return it. If the attribute cannot be parsed into the given `<attr-type>`, the `<fallback-value>` will be returned instead. When no `<attr-type>` is set, the attribute will be parsed into a CSS string.
 
-      - : The attribute value is parsed as a CSS {{CSSxRef("&lt;length&gt;")}} dimension, that is including the unit (e.g. `12.5em`). If it is not valid, that is not a length or out of the range accepted by the CSS property, the default value is used.
-        If the given unit is a relative length, `attr()` computes it to an absolute length.
-        Leading and trailing spaces are stripped.
+If no `<fallback-value>` is set, the return value will default to an empty string when no `<attr-type>` is set or the [guaranteed-invalid value](/en-US/docs/Glossary/guaranteed_invalid_value) when an `<attr-type>` is set.
 
-        Default value: `0`, or, if `0` is not a valid value for the property, the property's minimum value.
+## Description
 
-    - `em`, `ex`, `px`, `rem`, `vw`, `vh`, `vmin`, `vmax`, `mm`, `cm`, `in`, `pt`, or `pc`
+### Limitations and security
 
-      - : The attribute value is parsed as a CSS {{CSSxRef("&lt;number&gt;")}}, that is without the unit (e.g. `12.5`), and interpreted as a {{CSSxRef("&lt;length&gt;")}} with the specified unit. If it is not valid, that is not a number or out of the range accepted by the CSS property, the default value is used.
-        If the given unit is a relative length, `attr()` computes it to an absolute length.
-        Leading and trailing spaces are stripped.
+The `attr()` function can reference attributes that were never intended by the page author to be used for styling, and might contain sensitive information (for example, a security token used by scripts on the page). In general, this is fine, but it can become a security threat when used in URLs. You therefore can't use `attr()` to dynamically construct URLs.
 
-        Default value: `0`, or, if `0` is not a valid value for the property, the property's minimum value.
+```html
+<!-- This won't work! -->
+<span data-icon="https://example.org/icons/question-mark.svg">help</span>
+<style>
+  span[data-icon] {
+    background-image: url(attr(data-icon));
+  }
+</style>
+```
 
-    - `angle`
+Values that use `attr()` get marked as _"`attr()`-tained"_. Using an `attr()`-tainted value as or in a `<url>` makes a declaration become ["invalid at computed value time" or IACVT for short](https://brm.us/iacvt)
 
-      - : The attribute value is parsed as a CSS {{CSSxRef("&lt;angle&gt;")}} dimension, that is including the unit (e.g. `30.5deg`). If it is not valid, that is not an angle or out of the range accepted by the CSS property, the default value is used.
-        Leading and trailing spaces are stripped.
+### Backwards compatibility
 
-        Default value: `0deg`, or, if `0deg` is not a valid value for the property, the property's minimum value.
+Generally speaking, the modern `attr()` syntax is backwards-compatible because the old way of using it — without specifying an `<attr-type>` — behaves the same as before. Having `attr(data-attr)` in your code is the same as writing `attr(data-attr type(<string>))` or the simpler `attr(data-attr string))`.
 
-    - `deg`, `grad`, `rad`
+However, there are two edge cases where the modern `attr()` syntax behaves differently from the old syntax.
 
-      - : The attribute value is parsed as a CSS {{CSSxRef("&lt;number&gt;")}}, that is without the unit (e.g. `12.5`), and interpreted as an {{CSSxRef("&lt;angle&gt;")}} with the specified unit. If it is not valid, that is not a number or out of the range accepted by the CSS property, the default value is used.
-        Leading and trailing spaces are stripped.
+In the following snippet, browsers that don't support the modern `attr()` syntax will discard the second declaration because they cannot parse it. The result in those browsers is `"Hello World"`.
 
-        Default value: `0deg`, or, if `0deg` is not a valid value for the property, the property's minimum value.
+```html
+<div text="Hello"></div>
+```
 
-    - `time`
+```css
+div::before {
+  content: attr(text) " World";
+}
+div::before {
+  content: attr(text) 1px;
+}
+```
+
+In browsers with support for the modern syntax, the output will be … nothing. Those browsers will successfully parse the second declaration but, because it is invalid content for the `content` property, the declaration becomes ["invalid at computed value time" or IACVT for short](https://brm.us/iacvt).
 
-      - : The attribute value is parsed as a CSS {{CSSxRef("&lt;time&gt;")}} dimension, that is including the unit (e.g. `30.5ms`). If it is not valid, that is not a time or out of the range accepted by the CSS property, the default value is used.
-        Leading and trailing spaces are stripped.
+To prevent this kind of situation, [feature detection](#feature_detection) is recommended.
 
-        Default value: `0s`, or, if `0s` is not a valid value for the property, the property's minimum value.
+A second edge case is the following:
 
-    - `s`, `ms`
+```html
+<div id="parent"><div id="child" data-attr="foo"></div></div>
+```
 
-      - : The attribute value is parsed as a CSS {{CSSxRef("&lt;number&gt;")}}, that is without the unit (e.g. `12.5`), and interpreted as an {{CSSxRef("&lt;time&gt;")}} with the specified unit. If it is not valid, that is not a number or out of the range accepted by the CSS property, the default value is used.
-        Leading and trailing spaces are stripped.
+```css
+#parent {
+  --x: attr(data-attr);
+}
+#child::before {
+  content: var(--x);
+}
+```
 
-        Default value: `0s`, or, if `0s` is not a valid value for the property, the property's minimum value.
+Browsers without support for modern syntax display the text `"foo"`. In browsers with modern `attr()` support there is no output.
 
-    - `frequency`
+This is because `attr()` — similar to custom properties that use the `var()` function — get substituted at [computed value time](https://brm.us/iacvt/#custom-properties). With the modern behavior, `--x` first tries to read the `data-attr` attribute from the `#parent` element, which results in an empty string because there is no such attribute on `#parent`. That empty string then gets inherited by the `#child` element, resulting in a `content: ;` declaration being set.
 
-      - : The attribute value is parsed as a CSS {{CSSxRef("&lt;frequency&gt;")}} dimension, that is including the unit (e.g. `30.5kHz`). If it is not valid, that is not a frequency or out of the range accepted by the CSS property, the default value is used.
+To prevent this sort of situation, don't pass inherited `attr()` values onto children unless you explicitly want to.
 
-        Default value: `0Hz`, or, if `0Hz` is not a valid value for the property, the property's minimum value.
+### Feature detection
 
-    - `Hz`, `kHz`
+You can feature detect support for modern `attr()` syntax using the {{CSSxRef("@supports")}} at-rule. In the test, try to assign advanced `attr()` to a (non-custom) CSS property.
 
-      - : The attribute value is parsed as a CSS {{CSSxRef("&lt;number&gt;")}}, that is without the unit (e.g. `12.5`), and interpreted as a {{CSSxRef("&lt;frequency&gt;")}} with the specified unit. If it is not valid, that is not a number or out of the range accepted by the CSS property, the default value is used.
-        Leading and trailing spaces are stripped.
+For example:
 
-        Default value: `0Hz`, or, if `0Hz` is not a valid value for the property, the property's minimum value.
+```css
+@supports (x: attr(x type(*))) {
+  /* Browser has modern attr() support */
+}
 
-    - `%`
+@supports not (x: attr(x type(*))) {
+  /* Browser does not have modern attr() support */
+}
+```
 
-      - : The attribute value is parsed as a CSS {{CSSxRef("&lt;number&gt;")}}, that is without the unit (e.g. `12.5`), and interpreted as a {{CSSxRef("&lt;percentage&gt;")}}. If it is not valid, that is not a number or out of the range accepted by the CSS property, the default value is used.
-        If the given value is used as a length, `attr()` computes it to an absolute length.
-        Leading and trailing spaces are stripped.
+We can perform the same check in JavaScript with [`CSS.supports()`](/en-US/docs/Web/API/CSS/supports_static):
 
-        Default value: `0%`, or, if `0%` is not a valid value for the property, the property's minimum value.
+```js
+if (CSS.supports("x: attr(x type(*))")) {
+  /* Browser has modern attr() support */
+}
 
-- `<fallback>`
-  - : The value to be used if the associated attribute is missing or contains an invalid value. If not set, CSS will use the default value defined for each `<type-or-unit>`.
+if (!CSS.supports("x: attr(x type(*))")) {
+  /* Browser does not have modern attr() support */
+}
+```
 
 ## Formal syntax
 
@@ -171,6 +211,32 @@ In this example, we prepend the value of the `data-foo` [`data-*`](/en-US/docs/W
 
 {{EmbedLiveSample("content_property", "100%", 50)}}
 
+### Using a fallback value
+
+{{SeeCompatTable}}
+
+In this example, we append the value of `data-browser` [`data-*`](/en-US/docs/Web/HTML/Global_attributes/data-*) [global attribute](/en-US/docs/Web/HTML/Global_attributes) to the {{HTMLElement("p")}} element. If the `data-browser` attribute is missing from the {{HTMLElement("p")}} element, we append the _fallback_ value of "**Unknown**".
+
+#### HTML
+
+```html
+<p data-browser="Firefox">My favorite browser is:</p>
+<p>Your favorite browser is:</p>
+```
+
+#### CSS
+
+```css
+p::after {
+  content: " " attr(data-browser, "Unknown");
+  color: tomato;
+}
+```
+
+#### Result
+
+{{EmbedLiveSample("using_fallback", "100%", 90)}}
+
 ### color value
 
 {{SeeCompatTable}}
@@ -200,7 +266,7 @@ In this example, we set the CSS value of {{CSSXRef("background-color")}} to the
 }
 
 .background[data-background] {
-  background-color: attr(data-background color, red);
+  background-color: attr(data-background type(<color>), red);
 }
 ```
 
@@ -208,31 +274,191 @@ In this example, we set the CSS value of {{CSSXRef("background-color")}} to the
 
 {{EmbedLiveSample("color_value", "100%", 50)}}
 
-### using fallback
+### Using dimension units
 
 {{SeeCompatTable}}
 
-In this example, we append the value of `data-browser` [`data-*`](/en-US/docs/Web/HTML/Global_attributes/data-*) [global attribute](/en-US/docs/Web/HTML/Global_attributes) to the {{HTMLElement("p")}} element. If the `data-browser` attribute is missing from the {{HTMLElement("p")}} element, we append the _fallback_ value of "**Unknown**".
+In this example the `data-rotation` attribute is parsed into a `deg` unit, which specifies the element's rotation.
 
 #### HTML
 
 ```html
-<p data-browser="Firefox">My favorite browser is:</p>
-<p>Your favorite browser is:</p>
+<div data-rotation="-3">I am rotated by -3 degrees</div>
+<div data-rotation="2">And I by 2 degrees</div>
+<div>And so am I, using the fallback value of 1.5deg</div>
 ```
 
 #### CSS
 
+```css hidden
+body {
+  min-height: 100svh;
+  display: grid;
+  place-content: center;
+  gap: 1em;
+}
+div {
+  margin: 0 auto;
+  border: 1px solid;
+  border-radius: 0.25em;
+  padding: 0.5em;
+}
+```
+
 ```css
-p::after {
-  content: " " attr(data-browser, "Unknown");
-  color: tomato;
+div {
+  width: fit-content;
+  transform-origin: 50% 50%;
+  rotate: attr(data-rotation deg, 1.5deg);
 }
 ```
 
 #### Result
 
-{{EmbedLiveSample("using_fallback", "100%", 90)}}
+{{EmbedLiveSample("using_dimension_units", "100%", 300)}}
+
+### Parsing `attr()` values as `<custom-ident>`s
+
+{{SeeCompatTable}}
+
+In this example, the values for the {{cssxref("view-transition-name")}} property are derived from the `id` attribute of the element. The attribute gets parsed into a {{CSSxRef("&lt;custom-ident&gt;")}}, which is what {{cssxref("view-transition-name")}} accepts as a value.
+
+The resulting values for {{cssxref("view-transition-name")}} are `card-1`, `card-2`, `card-3`, etc.
+
+#### HTML
+
+The HTML contains four cards with different `id` attributes and a "Shuffle cards" `<button>`, which shuffles the cards.
+
+```html
+<div class="cards">
+  <div class="card" id="card-1">1</div>
+  <div class="card" id="card-2">2</div>
+  <div class="card" id="card-3">3</div>
+  <div class="card" id="card-4">4</div>
+</div>
+<button>Shuffle cards</button>
+```
+
+```html hidden
+<div class="warning">
+  <p>
+    You browser does not support advanced <code>attr()</code>. As a result, this
+    demo won’t do anything.
+  </p>
+</div>
+```
+
+#### CSS
+
+The cards are laid out in a flex container:
+
+```css
+.cards {
+  display: flex;
+  flex-direction: row;
+  gap: 1em;
+  padding: 1em;
+}
+```
+
+```css hidden
+:root {
+  view-transition-name: none;
+}
+::view-transition {
+  pointer-events: none;
+}
+
+@supports (x: attr(x type(*))) {
+  .warning {
+    display: none;
+  }
+}
+
+@layer layout {
+  .card {
+    border-radius: 0.25em;
+    width: 20vw;
+    max-width: 5em;
+    aspect-ratio: 1 / 1.6;
+    background: lightgrey;
+
+    display: grid;
+    place-content: center;
+    font-size: 2em;
+  }
+
+  * {
+    box-sizing: border-box;
+  }
+
+  body {
+    min-height: 100svh;
+    display: grid;
+    place-content: center;
+  }
+
+  button {
+    justify-self: center;
+  }
+}
+
+@layer warning {
+  .warning {
+    padding: 1em;
+    border: 1px solid #ccc;
+    background: rgba(255 255 205 / 0.8);
+    text-align: center;
+    order: -1;
+    margin: 1em;
+  }
+
+  .warning > :first-child {
+    margin-top: 0;
+  }
+  .warning > :last-child {
+    margin-bottom: 0;
+  }
+}
+```
+
+On each card, the `attr()` function gets the `id` attribute and parses it into a {{CSSxRef("&lt;custom-ident&gt;")}}, which is used as the value for the {{cssxref("view-transition-name")}} property. When there is no `id` set on a card, the fallback value `none` is used instead.
+
+```css
+.card {
+  view-transition-name: attr(id type(<custom-ident>), none);
+  view-transition-class: card;
+}
+```
+
+#### JavaScript
+
+When the `<button>` is pressed the cards are shuffled. This is done by randomizing the order of an array containing references to all the cards and then updating the {{CSSxRef("order")}} property of each card to its new array index position.
+
+To animate each card to its new position, [View Transitions](/en-US/docs/Web/API/View_Transition_API/Using) are used. This is done by wrapping the `order` update in a call to [`document.startViewTransition`](/en-US/docs/Web/API/Document/startViewTransition).
+
+```js
+const shuffle = (array) => {
+  for (let i = array.length - 1; i >= 0; i--) {
+    const j = Math.floor(Math.random() * (i + 1));
+    [array[i], array[j]] = [array[j], array[i]];
+  }
+};
+
+document.querySelector("button").addEventListener("click", (e) => {
+  const $cards = Array.from(document.querySelectorAll(".card"));
+  shuffle($cards);
+  document.startViewTransition(() => {
+    $cards.forEach(($card, i) => {
+      $card.style.setProperty("order", i);
+    });
+  });
+});
+```
+
+#### Result
+
+{{EmbedLiveSample("parsing_attr_values_as_custom-idents", "100%", 400)}}
 
 ## Specifications
 
diff --git a/files/en-us/web/css/backdrop-filter/index.md b/files/en-us/web/css/backdrop-filter/index.md
index 03b805456f8be22..7b13c3f7fface61 100644
--- a/files/en-us/web/css/backdrop-filter/index.md
+++ b/files/en-us/web/css/backdrop-filter/index.md
@@ -47,7 +47,7 @@ backdrop-filter: unset;
 
 - `none`
   - : No filter is applied to the backdrop.
-- `<filter-function-list>`
+- `<filter-value-list>`
   - : A space-separated list of {{cssxref("&lt;filter-function&gt;")}}s or an [SVG filter](/en-US/docs/Web/SVG/Element/filter) that will be applied to the backdrop. CSS `<filter-function>`s include {{CSSxRef("filter-function/blur", "blur()")}}, {{CSSxRef("filter-function/brightness", "brightness()")}}, {{CSSxRef("filter-function/contrast", "contrast()")}}, {{CSSxRef("filter-function/drop-shadow", "drop-shadow()")}}, {{CSSxRef("filter-function/grayscale", "grayscale()")}}, {{CSSxRef("filter-function/hue-rotate", "hue-rotate()")}}, {{CSSxRef("filter-function/invert", "invert()")}}, {{CSSxRef("filter-function/opacity", "opacity()")}}, {{CSSxRef("filter-function/saturate", "saturate()")}}, and {{CSSxRef("filter-function/sepia", "sepia()")}}.
 
 ## Formal definition
diff --git a/files/en-us/web/css/baseline-position/index.md b/files/en-us/web/css/baseline-position/index.md
new file mode 100644
index 000000000000000..a00159f949e2944
--- /dev/null
+++ b/files/en-us/web/css/baseline-position/index.md
@@ -0,0 +1,49 @@
+---
+title: <baseline-position>
+slug: Web/CSS/baseline-position
+page-type: css-type
+browser-compat: css.types.baseline-position
+---
+
+{{CSSRef}}
+
+The **`<baseline-position>`** {{glossary("enumerated")}} value type represents the `baseline` keyword values and `first` and `last` modifiers, used for the {{cssxref("align-content")}}, {{cssxref("align-items")}}, {{cssxref("align-self")}}, {{cssxref("justify-items")}} and {{cssxref("justify-self")}} properties as well as the {{cssxref("place-content")}}, {{cssxref("place-items")}}, and {{cssxref("place-self")}} shorthand properties.
+
+The `first` and `last` values give a box a baseline alignment preference, defaulting to `first` if the modifier is omitted.
+
+## Syntax
+
+```plain
+<baseline-position> = [ first | last ]? && baseline
+```
+
+## Values
+
+The `<baseline-position>` enumerated value type is specified using an optional `first` or `last` modifier with the `baseline` value. If a box does not belong to a shared alignment context, then the fallback alignment is used. The fallback alignment is also used to align the baseline-sharing group within its {{glossary("alignment container")}}.
+
+- `baseline`
+
+  - : Computes to `first baseline`, as defined below.
+
+- `first baseline`
+
+  - : Aligns the alignment baseline of the box's first baseline set with the corresponding baseline of its baseline-sharing group. The fallback alignment is `safe self-start` for self-alignment or `safe start` for content distribution.
+
+- `last baseline`
+  - : Aligns the alignment baseline of the box's last baseline set with the corresponding baseline of its baseline-sharing group. The fallback alignment is `safe self-end` for self-alignment or `safe end` for content distribution.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- Properties that use this data type: {{cssxref("align-content")}}, {{cssxref("align-items")}}, {{cssxref("align-self")}}, {{cssxref("justify-items")}}, {{cssxref("justify-self")}}, {{cssxref("place-content")}}, {{cssxref("place-items")}}, and {{cssxref("place-self")}}
+- Other box alignment data types: {{cssxref("content-distribution")}}, {{cssxref("content-position")}}, {{cssxref("overflow-position")}}, and {{cssxref("self-position")}}
+- [CSS box alignment](/en-US/docs/Web/CSS/CSS_box_alignment) module
+- [CSS flexible box layout](/en-US/docs/Web/CSS/CSS_flexible_box_layout) module
+- [CSS grid layout](/en-US/docs/Web/CSS/CSS_grid_layout) module
diff --git a/files/en-us/web/css/content-distribution/index.md b/files/en-us/web/css/content-distribution/index.md
new file mode 100644
index 000000000000000..3eb5e49af4aa71e
--- /dev/null
+++ b/files/en-us/web/css/content-distribution/index.md
@@ -0,0 +1,52 @@
+---
+title: <content-distribution>
+slug: Web/CSS/content-distribution
+page-type: css-type
+browser-compat: css.types.content-distribution
+---
+
+{{CSSRef}}
+
+The **`<content-distribution>`** {{glossary("enumerated")}} value type is used by {{cssxref("justify-content")}} and {{cssxref("align-content")}} properties, and the {{cssxref("place-content")}} shorthand, to distribute a container's extra space among its {{glossary("alignment subject", "alignment subjects")}}.
+
+## Syntax
+
+```plain
+<content-distribution> = space-between | space-around | space-evenly | stretch
+```
+
+## Values
+
+The following keyword values are represented by the `<content-distribution>` grammar term:
+
+- `space-between`
+
+  - : Evenly distributes the {{glossary("alignment subject")}} within the {{glossary("alignment container")}}. The first item is placed flush with the start edge of the alignment container, the last item subject is placed flush with the end edge of the alignment container, and the remaining items are evenly distributed so that the spacing between any two adjacent items is the same. The default fallback alignment for `space-between` is `safe flex-start` for flex layout, and `start` otherwise. If there is only one item, the item will be flush with the start edge.
+
+- `space-around`
+
+  - : The items are evenly distributed in the container, with a half-size space on either end. The spacing between any two adjacent items is the same, and the spacing before the first and after the last items is half the size of the other spacing. The default fallback alignment for `space-around` is `safe center`. If the container has only one child, the item will be centered.
+
+- `space-evenly`
+
+  - : The items are evenly distributed in the container, with a full-size space on either end. The spacing between any two adjacent items, before the first item, and after the last item, are all the same. The default fallback alignment for `space-evenly` is `safe center`. If the container has only one child, the item will be centered.
+
+- `stretch`
+
+  - : If the combined size of the items is less than the size of the container, any items that can grow will have their size increased equally (not proportionally), while still respecting the constraints imposed by {{cssxref("max-height")}}, {{cssxref("max-width")}}, or equivalent functionality, so that the combined size of the items exactly fills the container. The default fallback alignment for `stretch` is `flex-start` in flexbox, and `start` in other layout modes. If there is only one item, and that item can grow, it will grow to fill the container.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- Properties that use this data type: {{cssxref("align-content")}}, {{cssxref("justify-content")}}, {{cssxref("place-content")}}
+- Other box alignment data types: {{cssxref("baseline-position")}}, {{cssxref("content-position")}}, {{cssxref("overflow-position")}}, and {{cssxref("self-position")}}
+- [CSS box alignment](/en-US/docs/Web/CSS/CSS_box_alignment) module
+- [CSS flexible box layout](/en-US/docs/Web/CSS/CSS_flexible_box_layout) module
+- [CSS grid layout](/en-US/docs/Web/CSS/CSS_grid_layout) module
diff --git a/files/en-us/web/css/content-position/index.md b/files/en-us/web/css/content-position/index.md
new file mode 100644
index 000000000000000..713036ab3b8936f
--- /dev/null
+++ b/files/en-us/web/css/content-position/index.md
@@ -0,0 +1,50 @@
+---
+title: <content-position>
+slug: Web/CSS/content-position
+page-type: css-type
+browser-compat: css.types.content-position
+---
+
+{{CSSRef}}
+
+The **`<content-position>`** {{glossary("enumerated")}} value type is used by {{cssxref("justify-content")}} and {{cssxref("align-content")}} properties, and the {{cssxref("place-content")}} shorthand, to align the box's contents within itself.
+
+## Syntax
+
+```plain
+<content-position> = center | start | end | flex-start | flex-end
+```
+
+## Values
+
+The `<content-position>` enumerated value type is specified using one of the following key terms.
+
+- `center`
+  - : Centers the {{glossary("alignment subject")}} within its {{glossary("alignment container")}}.
+- `start`
+  - : Aligns the alignment subject flush with the alignment container's start edge.
+- `end`
+  - : Aligns the alignment subject flush with the alignment container's end edge.
+- `flex-start`
+  - : In flex layout, aligns the alignment subject flush with the edge of the alignment container corresponding to the flex container's main-start or cross-start side, as appropriate. It is identical to `start` for layout modes other than flex layout.
+- `flex-end`
+  - : In flex layout, aligns the alignment subject flush with the edge of the alignment container corresponding to the flex container's main-end or cross-end side, as appropriate. Identical to `end` for layout modes other than flex layout.
+
+> [!NOTE]
+> The `left` and `right` keywords are excluded from `<content-position>`, despite being valid positional alignment values for the `justify-*` properties ({{cssxref("justify-content")}}, {{cssxref("justify-self")}}, and {{cssxref("justify-items")}}), because they are not allowed in the `align-*` properties ({{cssxref("align-content")}}, {{cssxref("align-self")}}, and {{cssxref("align-items")}}). They are instead explicitly included in the `justify-*` properties' grammars.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- Properties that use this data type: {{cssxref("align-content")}}, {{cssxref("justify-content")}}, {{cssxref("place-content")}}
+- Other box alignment data types: {{cssxref("baseline-position")}}, {{cssxref("content-distribution")}}, {{cssxref("content-position")}}, {{cssxref("overflow-position")}}, and {{cssxref("self-position")}}
+- [CSS box alignment](/en-US/docs/Web/CSS/CSS_box_alignment) module
+- [CSS flexible box layout](/en-US/docs/Web/CSS/CSS_flexible_box_layout) module
+- [CSS grid layout](/en-US/docs/Web/CSS/CSS_grid_layout) module
diff --git a/files/en-us/web/css/css_box_alignment/align-container-subjects.png b/files/en-us/web/css/css_box_alignment/box_alignment/align-container-subjects.png
similarity index 100%
rename from files/en-us/web/css/css_box_alignment/align-container-subjects.png
rename to files/en-us/web/css/css_box_alignment/box_alignment/align-container-subjects.png
diff --git a/files/en-us/web/css/css_box_alignment/box_alignment/index.md b/files/en-us/web/css/css_box_alignment/box_alignment/index.md
new file mode 100644
index 000000000000000..a4e5fa1dffabb24
--- /dev/null
+++ b/files/en-us/web/css/css_box_alignment/box_alignment/index.md
@@ -0,0 +1,288 @@
+---
+title: CSS box alignment overview
+slug: Web/CSS/CSS_box_alignment/Box_alignment
+page-type: guide
+---
+
+{{CSSRef}}
+
+The [CSS box alignment](/en-US/docs/Web/CSS/CSS_box_alignment) module specifies CSS features that relate to the alignment of boxes in the various CSS box layout models. The module aims to create a consistent method of alignment across all of CSS. The CSS box alignment properties provide full horizontal and vertical alignment capabilities.
+
+This guide details the general concepts found in this module. Additional guides provide more information on box alignment in [flexbox](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment_in_flexbox), [grid layout](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment_in_grid_layout), [multiple-column layout](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment_in_multi-column_layout), and [block, absolutely positioned and table layout](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment_in_block_abspos_tables). Alignment of text is covered by the [CSS text](/en-US/docs/Web/CSS/CSS_text) and [CSS inline layout](/en-US/docs/Web/CSS/CSS_inline_layout) modules.
+
+## Key concepts and terminology
+
+The specification details some alignment terminology to make it easier to discuss these alignment properties outside their implementation within a particular layout method. There are also some key concepts which are common to all layout methods.
+
+### Relationship to writing modes
+
+Alignment is linked to writing modes in that when we align an item we do not consider whether we are aligning it to the physical dimensions of top, right, bottom and left. Instead we describe alignment in terms of the start and end of the particular dimension we are working with. This ensures that alignment works in the same way whichever writing mode the document has.
+
+### Two dimensions of alignment
+
+When using the box alignment properties you will align content on one of two axes — the inline (or main) axis, and the block (or cross) axis. The inline axis is the axis along which words in a sentence flow in the writing mode being used. For English, for example, the inline axis is horizontal. The block axis is the axis along which blocks, such as paragraph elements, are laid out; it runs across the Inline axis.
+
+![Inline axis is the left / right, or horizontal, direction. Block axis is vertical, or top / bottom.](two-axes.png)
+
+When aligning items on the inline axis you will use the properties that begin with `justify-`:
+
+- {{cssxref("justify-items")}}
+- {{cssxref("justify-self")}}
+- {{cssxref("justify-content")}}
+
+When aligning items on the block axis you will use the properties that begin with `align-`:
+
+- {{cssxref("align-items")}}
+- {{cssxref("align-self")}}
+- {{cssxref("align-content")}}
+
+Flexbox adds an additional complication in that the above is true when {{cssxref("flex-direction")}} is set to `row`. The properties are swapped when flexbox is set to `column`. Therefore, when working with flexbox it is easier to think about the main and cross axis rather than inline and block. The `justify-` properties are always used to align on the main axis, the `align-` properties on the cross axis.
+
+### The alignment subject
+
+The **{{Glossary("alignment subject")}}** is the thing that is being aligned. For `justify-self` or `align-self`, or when setting these values as a group with `justify-items` or `align-items`, this will be the margin box of the element that this property is being used on. The `justify-content` and `align-content` properties differ per layout method.
+
+### The alignment container
+
+The **{{Glossary("alignment container")}}** is the box the subject is being aligned inside. This will typically be the alignment subject's containing block. An alignment container may contain one or many alignment subjects.
+
+The below image shows an alignment container with two alignment subjects inside.
+
+![A box containing two rectangles of the same width but different heights. The two rectangles are top aligned, meaning they both have their top lines about 10px inside the top of the box in which they are contained.](align-container-subjects.png)
+
+## Types of alignment
+
+There are three different types of alignment that the specification details; these use keyword values.
+
+- [Positional alignment](#positional-alignment)
+- [Baseline alignment](#baseline-alignment)
+- [Distributed alignment](#distributed-alignment)
+
+### Positional alignment
+
+**Positional alignment** is the position of an alignment subject with relation to its alignment container. The positional alignment keyword values are defined for positional alignment, and can be used as values for content alignment with `justify-content` and `align-content` and also for self alignment with `justify-self` and `align-self`.
+
+- `center`
+- `start`
+- `end`
+- `self-start`
+- `self-end`
+- `flex-start` for flexbox only
+- `flex-end` for flexbox only
+- `left`
+- `right`
+
+Other than the physical values of `left` and `right`, which relate to physical attributes of the screen, all of the other values, the {{cssxref("self-position")}} and {{cssxref("content-position")}} values, are logical values and relate to the writing mode of the content.
+
+For example, when working in CSS grid layout, if you are working in English and set `justify-content` to `start` this will move the items in the inline dimension to the start, which will be the left as sentences in English start on the left-hand side of the page. If you were using Arabic, a right-to-left language, then the same value of `start` would result in the items moving to the right, as sentences in Arabic start on the right-hand side of the page.
+
+![There are two boxes, each with 3 children of differing heights but similar widths. The first box has three children with the letters A, B, and C. These three boxes are all aligned to the left. The second box has three children with arabic letters in them. Those three boxes are all aligned to the right.](writing-mode-start.png)
+
+Both have `justify-content: start`, but the location of the two starts is different because of the writing mode.
+
+### Baseline alignment
+
+**Baseline alignment** is the relationship among the baselines of multiple alignment subjects within an alignment context. The Baseline alignment {{cssxref("baseline-position")}} keywords are used to align the baselines of boxes across a group of alignment subjects. They can be used as values for content alignment with `justify-content` and `align-content` and self-alignment with `justify-self` and `align-self`.
+
+- `baseline`
+- `first baseline`
+- `last baseline`
+
+Baseline content alignment — specifying a baseline alignment value for `justify-content` or `align-content` — works in layout methods that lay items out in rows. The alignment subjects are baseline aligned against each other by adding padding inside the boxes.
+
+Baseline self-alignment shifts the boxes to align by baseline by adding a margin outside the boxes. Self-alignment is done for singular boxes using `justify-self` or `align-self`, or for groups of boxes using `justify-items` and `align-items`.
+
+### Distributed alignment
+
+**Distributed alignment** defines alignment as a distribution of space among alignment subjects. The distributed alignment {{cssxref("content-distribution")}} keywords are used with the `align-content` and `justify-content` properties. These keywords define what happens to any additional space after alignment subjects have been displayed. The values are as follows:
+
+- `stretch`
+- `space-between`
+- `space-around`
+- `space-evenly`
+
+For example, in Flex Layout items are aligned with `flex-start` initially. Working in a horizontal top-to-bottom writing mode (with a language such as English), with `flex-direction` set to `row`, the items start on the far left, and any available space after displaying the items is placed after them.
+
+![Three rectangles of different widths are inside a box. They are all aligned to the left side of the containing box, with about 10px between them, and 10px between the left side of the first rectangle and the parent container.](justify-content-start.png)
+
+If you set `justify-content: space-between` on the flex container, the available space is now shared out and placed between the items.
+
+![Three rectangles of different widths are inside a box. The first rectangle is aligned to the left side of the containing box, the third rectangle is aligned right, and the middle rectangle is equally spaced between the first and last.](justify-content-space-between.png)
+
+For these keywords to take effect, space is required along the dimension in which you wish to align the items. With no space, there is nothing to distribute.
+
+### Basic examples
+
+The following examples demonstrate how some of the box alignment properties are applied in [Grid](/en-US/docs/Web/CSS/CSS_grid_layout) and [Flexbox](/en-US/docs/Web/CSS/CSS_flexible_box_layout).
+
+#### CSS grid layout alignment example
+
+In this grid layout example, there is extra space in the grid container after laying out the fixed-width tracks on the inline (main) axis. This space is distributed using {{cssxref("justify-content")}}. On the block (cross) axis, the alignment of the items inside their grid areas is controlled with {{cssxref("align-items")}}. The first item overrides the `align-items` value set on the group by setting {{cssxref("align-self")}} to `center`.
+
+```html live-sample___grid-align-items
+<div class="box">
+  <div>One</div>
+  <div>Two</div>
+  <div>Three <br />has <br />extra <br />text</div>
+  <div>Four</div>
+  <div>Five</div>
+  <div>Six</div>
+</div>
+```
+
+```css hidden live-sample___grid-align-items
+body {
+  font: 1.2em sans-serif;
+}
+
+.box {
+  border: 2px dotted rgb(96 139 168);
+}
+
+.box > * {
+  padding: 20px;
+  border: 2px solid rgb(96 139 168);
+  border-radius: 5px;
+  background-color: rgb(96 139 168 / 0.2);
+}
+```
+
+```css live-sample___grid-align-items
+.box {
+  display: grid;
+  grid-template-columns: 120px 120px 120px;
+  align-items: start;
+  justify-content: space-between;
+}
+
+.box :first-child {
+  align-self: center;
+}
+```
+
+{{EmbedLiveSample("grid-align-items", "", "200px")}}
+
+#### Flexbox Alignment Example
+
+In this example, three flex items are aligned on the main axis using `justify-content` and on the cross axis using `align-items`. The first item overrides the `align-items` set on the group by setting `align-self` to `center`.
+
+```html live-sample___flex-align-items
+<div class="box">
+  <div>One</div>
+  <div>Two</div>
+  <div>Three <br />has <br />extra <br />text</div>
+</div>
+```
+
+```css hidden live-sample___flex-align-items
+body {
+  font: 1.2em sans-serif;
+}
+
+.box {
+  border: 2px dotted rgb(96 139 168);
+}
+
+.box > * {
+  padding: 20px;
+  border: 2px solid rgb(96 139 168);
+  border-radius: 5px;
+  background-color: rgb(96 139 168 / 0.2);
+}
+```
+
+```css live-sample___flex-align-items
+.box {
+  display: flex;
+  align-items: flex-start;
+  justify-content: space-between;
+}
+
+.box :first-child {
+  align-self: center;
+}
+```
+
+{{EmbedLiveSample("flex-align-items")}}
+
+## Overflow alignment
+
+The {{cssxref("overflow-position")}} keywords `safe` and `unsafe` help define behavior when an alignment subject is larger than the alignment container. The `safe` keyword will align to `start` in the case of a specified alignment causing an overflow, the aim being to avoid "data loss" where part of the item is outside the boundaries of the alignment container and can't be scrolled to.
+
+If you specify `unsafe` then the alignment will be honoured even if it would cause such data loss.
+
+## Gaps between boxes
+
+The box alignment specification also includes the `gap`, `row-gap`, and `column-gap` properties. These properties enable the setting of a consistent gap between items in a row or column, in any layout method which has items arranged in this way.
+
+The `gap` property is a shorthand for `row-gap` and `column-gap`, which allows us to set these properties at once:
+
+- {{cssxref("row-gap")}}
+- {{cssxref("column-gap")}}
+- {{cssxref("gap")}}
+
+In the below example, a grid layout uses the `gap` shorthand to set a `10px` gap between row tracks, and a `2em` gap between column tracks.
+
+```html live-sample___grid-gap
+<div class="box">
+  <div>One</div>
+  <div>Two</div>
+  <div>Three</div>
+  <div>Four</div>
+  <div>Five</div>
+  <div>Six</div>
+</div>
+```
+
+```css hidden live-sample___grid-gap
+body {
+  font: 1.2em sans-serif;
+}
+
+.box {
+  border: 2px dotted rgb(96 139 168);
+}
+
+.box > * {
+  padding: 20px;
+  border: 2px solid rgb(96 139 168);
+  border-radius: 5px;
+  background-color: rgb(96 139 168 / 0.2);
+}
+```
+
+```css live-sample___grid-gap
+.box {
+  display: grid;
+  grid-template-columns: 1fr 1fr 1fr;
+  gap: 10px 2em;
+}
+
+.box :first-child {
+  align-self: center;
+}
+```
+
+{{EmbedLiveSample("grid-gap")}}
+
+Early grid implementations included `gap` properties prefixed with `grid-`. All browsers support the unprefixed properties, though you may see the following properties in a code-base: {{cssxref("row-gap", "grid-row-gap")}}, {{cssxref("column-gap", "grid-column-gap")}}, and {{cssxref("gap", "grid-gap")}}. The prefixed versions are aliases of the unprefixed ones.
+
+Be aware that other things may increase the visual gap displayed, for example using the space distribution keywords or adding margins to items.
+
+## Box-alignment by layout type
+
+As the CSS box alignment properties are implemented differently depending on the specification they interact with, refer to the following guides for details of how to use the alignment properties with each layout type:
+
+- [Box alignment in flexbox](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment_in_flexbox)
+- [Box alignment in CSS grid layout](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment_in_grid_layout)
+- [Box alignment in multiple-column layout](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment_in_multi-column_layout)
+- [Box alignment for block, absolutely positioned and table layout](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment_in_block_abspos_tables)
+
+## See also
+
+- [CSS display](/en-US/docs/Web/CSS/CSS_display) module
+- [CSS flex layout](/en-US/docs/Web/CSS/CSS_flexible_box_layout) module
+- [Basic concepts of flexbox](/en-US/docs/Web/CSS/CSS_flexible_box_layout/Basic_concepts_of_flexbox)
+- [Aligning items in a flex container](/en-US/docs/Web/CSS/CSS_flexible_box_layout/Aligning_items_in_a_flex_container)
+- [CSS grid layout](/en-US/docs/Web/CSS/CSS_grid_layout) module
+- [Box alignment in CSS grid layouts](/en-US/docs/Web/CSS/CSS_grid_layout/Box_alignment_in_grid_layout)
diff --git a/files/en-us/web/css/css_box_alignment/justify-content-space-between.png b/files/en-us/web/css/css_box_alignment/box_alignment/justify-content-space-between.png
similarity index 100%
rename from files/en-us/web/css/css_box_alignment/justify-content-space-between.png
rename to files/en-us/web/css/css_box_alignment/box_alignment/justify-content-space-between.png
diff --git a/files/en-us/web/css/css_box_alignment/justify-content-start.png b/files/en-us/web/css/css_box_alignment/box_alignment/justify-content-start.png
similarity index 100%
rename from files/en-us/web/css/css_box_alignment/justify-content-start.png
rename to files/en-us/web/css/css_box_alignment/box_alignment/justify-content-start.png
diff --git a/files/en-us/web/css/css_box_alignment/two-axes.png b/files/en-us/web/css/css_box_alignment/box_alignment/two-axes.png
similarity index 100%
rename from files/en-us/web/css/css_box_alignment/two-axes.png
rename to files/en-us/web/css/css_box_alignment/box_alignment/two-axes.png
diff --git a/files/en-us/web/css/css_box_alignment/writing-mode-start.png b/files/en-us/web/css/css_box_alignment/box_alignment/writing-mode-start.png
similarity index 100%
rename from files/en-us/web/css/css_box_alignment/writing-mode-start.png
rename to files/en-us/web/css/css_box_alignment/box_alignment/writing-mode-start.png
diff --git a/files/en-us/web/css/css_box_alignment/box_alignment_in_block_abspos_tables/index.md b/files/en-us/web/css/css_box_alignment/box_alignment_in_block_abspos_tables/index.md
index 750ee20c8c120bc..f5f57d0bdb8f610 100644
--- a/files/en-us/web/css/css_box_alignment/box_alignment_in_block_abspos_tables/index.md
+++ b/files/en-us/web/css/css_box_alignment/box_alignment_in_block_abspos_tables/index.md
@@ -4,7 +4,7 @@ slug: Web/CSS/CSS_box_alignment/Box_alignment_in_block_abspos_tables
 page-type: guide
 ---
 
-The [box alignment specification](/en-US/docs/Web/CSS/CSS_box_alignment) details how alignment works in various layout methods. In this page we explore how box alignment works in the context of block layout, including floated, positioned, and table elements. As this page aims to detail things which are specific to block layout and box alignment, it should be read in conjunction with the main [box alignment](/en-US/docs/Web/CSS/CSS_box_alignment) page, which details the common features of box alignment across layout methods.
+The [CSS box alignment](/en-US/docs/Web/CSS/CSS_box_alignment) module details how alignment works in various layout methods. In this guide, we explore how box alignment works in the context of block layout, including floated, positioned, and table elements. As this guide aims to detail things which are specific to block layout and box alignment, it should be read in conjunction with the [box alignment](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment) guide, which details the common features of box alignment across layout methods.
 
 ## align-content and justify-content
 
@@ -75,19 +75,9 @@ For many use cases, turning the block container into a flex item will give you t
 
 {{EmbedLiveSample("intro", "", "320px")}}
 
-## Reference
+## See also
 
-### CSS Properties
-
-- {{cssxref("justify-content")}}
-- {{cssxref("align-content")}}
-- {{cssxref("justify-self")}}
-- {{cssxref("align-self")}}
-
-### Glossary Entries
-
-- [Alignment subject](/en-US/docs/Glossary/Alignment_Subject)
-- [Alignment container](/en-US/docs/Glossary/Alignment_Container)
-- [Fallback alignment](/en-US/docs/Glossary/Fallback_Alignment)
-
-{{CSSRef}}
+- [Box alignment overview](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment)
+- [Box alignment in flexbox](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment_in_flexbox)
+- [Box alignment in CSS grid layout](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment_in_grid_layout)
+- [Box alignment in multiple-column layout](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment_in_multi-column_layout)
diff --git a/files/en-us/web/css/css_box_alignment/box_alignment_in_flexbox/index.md b/files/en-us/web/css/css_box_alignment/box_alignment_in_flexbox/index.md
index f624a620217c87d..c44819db54f7924 100644
--- a/files/en-us/web/css/css_box_alignment/box_alignment_in_flexbox/index.md
+++ b/files/en-us/web/css/css_box_alignment/box_alignment_in_flexbox/index.md
@@ -6,11 +6,11 @@ page-type: guide
 
 {{CSSRef}}
 
-The [box alignment](/en-US/docs/Web/CSS/CSS_box_alignment) Specification details how alignment works in various layout methods; on this page, we explore how box alignment works in the context of flexbox. As this page aims to detail things which are specific to flexbox and box alignment, it should be read in conjunction with the main [box alignment](/en-US/docs/Web/CSS/CSS_box_alignment) page which details the common features of box alignment across layout methods.
+The [box alignment](/en-US/docs/Web/CSS/CSS_box_alignment) module details how alignment works in various layout methods. In this guide, we explore how box alignment works in the context of [flexbox](/en-US/docs/Web/CSS/CSS_flexible_box_layout/Basic_concepts_of_flexbox). As this guide aims to detail things which are specific to flexbox and box alignment, it should be read in conjunction with the [box alignment overview](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment) guide, which details the common features of box alignment across layout methods.
 
 ## Basic example
 
-In this example, three flex items are aligned on the main axis using {{cssxref("justify-content")}} and on the cross axis using {{cssxref("align-items")}}. The first item overrides the `align-items` values set on the group by setting {{cssxref("align-self")}} to `center`.
+In this flexbox example, three flex items are aligned on the main axis using {{cssxref("justify-content")}} and on the cross axis using {{cssxref("align-items")}}. The first item overrides the `align-items` values set on the group by setting {{cssxref("align-self")}} to `center`.
 
 ```html live-sample___flex-align-items
 <div class="box">
@@ -51,7 +51,7 @@ Flexbox respects the writing mode of the document, therefore if you are working
 However, in flexbox you can change the main axis by setting `flex-direction` to `column`. In this case, `justify-content` will align items in the block direction. Therefore it is easiest to think about the main and cross axis when working in flexbox like so:
 
 - The main axis = direction set by `flex-direction` = alignment via `justify-content`
-- The cross axis = runs across the main axis = alignment via `align-content`, `align-self`/`align-items`
+- The cross axis = runs across the main axis = alignment via {{cssxref("align-content")}}, {{cssxref("align-self")}}/{{cssxref("align-items")}}
 
 ### Main Axis Alignment
 
@@ -65,7 +65,7 @@ However, in flexbox you can change the main axis by setting `flex-direction` to
 
 ### There is no justify-self in flexbox
 
-On the main axis, Flexbox deals with our content as a group. The amount of space required to lay out the items is calculated, and the leftover space is then available for distribution. The `justify-content` property controls how that leftover space is used. Set `justify-content: flex-end` and the extra space is placed before the items, `justify-content: space-around` and it is placed either side of the item in that dimension, etc.
+On the main axis, Flexbox deals with the flex items as a group. The amount of space required to lay out the items is calculated, and the leftover space is then available for distribution. The `justify-content` property controls how that leftover space is used. Set `justify-content: flex-end` and the extra space is placed before the items, `justify-content: space-around` and it is placed either side of the item in that dimension, etc.
 
 This means that a `justify-self` property does not make sense in flexbox as we are always dealing with moving the entire group of items around.
 
@@ -118,7 +118,7 @@ By setting a {{cssxref("margin")}} of `auto` on one item in a set of flex items
 
 On the main axis, the `column-gap` property creates fixed size gaps between adjacent items.
 
-On the cross axis the `row-gap` property creates spacing between adjacent flex lines, therefore `flex-wrap` must also be set to `wrap` for this to have any effect.
+On the cross axis the `row-gap` property creates spacing between adjacent flex lines, therefore {{cssxref("flex-wrap")}} must also be set to `wrap` for this to have any effect.
 
 ```html live-sample___gap
 <div class="box">
@@ -157,26 +157,12 @@ On the cross axis the `row-gap` property creates spacing between adjacent flex l
 
 {{EmbedLiveSample("gap")}}
 
-## Reference
-
-### CSS Properties
-
-- {{cssxref("justify-content")}}
-- {{cssxref("align-content")}}
-- {{cssxref("place-content")}}
-- {{cssxref("justify-items")}}
-- {{cssxref("align-items")}}
-- {{cssxref("place-items")}}
-- {{cssxref("align-self")}}
-- {{cssxref("row-gap")}}
-- {{cssxref("column-gap")}}
-- {{cssxref("gap")}}
-
-### Glossary Entries
+## See also
 
+- [Box alignment overview](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment)
+- [Box alignment in CSS grid layout](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment_in_grid_layout)
+- [Box alignment in multiple-column layout](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment_in_multi-column_layout)
+- [Box alignment for block, absolutely positioned and table layout](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment_in_block_abspos_tables)
+- [Alignment in flexbox](/en-US/docs/Web/CSS/CSS_flexible_box_layout/Aligning_items_in_a_flex_container)
 - {{Glossary("Cross axis")}}
 - {{Glossary("Main axis")}}
-
-## Guides
-
-- [Alignment in flexbox](/en-US/docs/Web/CSS/CSS_flexible_box_layout/Aligning_items_in_a_flex_container)
diff --git a/files/en-us/web/css/css_box_alignment/box_alignment_in_grid_layout/index.md b/files/en-us/web/css/css_box_alignment/box_alignment_in_grid_layout/index.md
index b18ef81173e3d18..a272fcf9689d18c 100644
--- a/files/en-us/web/css/css_box_alignment/box_alignment_in_grid_layout/index.md
+++ b/files/en-us/web/css/css_box_alignment/box_alignment_in_grid_layout/index.md
@@ -6,13 +6,13 @@ page-type: guide
 
 {{CSSRef}}
 
-The [box alignment](/en-US/docs/Web/CSS/CSS_box_alignment) specification details how alignment works in various layout methods. On this page we explore how box alignment works in the context of [CSS grid layout](/en-US/docs/Web/CSS/CSS_grid_layout).
+The [CSS box alignment](/en-US/docs/Web/CSS/CSS_box_alignment) module details how alignment works in various layout methods. On this page, we explore how box alignment works in the context of [CSS grid layout](/en-US/docs/Web/CSS/CSS_grid_layout).
 
-As this page aims to detail things which are specific to CSS grid layout and Box Alignment, it should be read in conjunction with the main [box alignment](/en-US/docs/Web/CSS/CSS_box_alignment) page which details the common features of box alignment across layout methods.
+As this guide aims to detail things which are specific to CSS grid layout and Box Alignment, it should be read in conjunction with the [box alignment overview](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment) guide, which details the common features of box alignment across layout methods.
 
 ## Basic example
 
-In this example using grid layout, there is extra space in the grid container after laying out the fixed width tracks on the inline (main) axis. This space is distributed using `justify-content`. On the block (cross) axis the alignment of the items inside their grid areas is controlled with `align-items`. The first item overrides the `align-items` value set on the group by setting `align-self` to `center`.
+In this example using [grid layout](/en-US/docs/Web/CSS/CSS_grid_layout/Basic_concepts_of_grid_layout), there is extra space in the {{glossary("grid container")}} after laying out the fixed-width tracks on the inline {{glossary("main axis")}}. This space is distributed using {{cssxref("justify-content")}}. On the block {{glossary("cross axis")}} the alignment of the items inside their grid areas is controlled with {{cssxref("align-items")}}. The first item overrides the `align-items` value set on the group by setting {{cssxref("align-self")}} to `center`.
 
 {{EmbedGHLiveSample("css-examples/box-alignment/overview/grid-align-items.html", '100%', 500)}}
 
@@ -20,13 +20,13 @@ In this example using grid layout, there is extra space in the grid container af
 
 As a two-dimensional layout method, when working with grid layout we always have two axes on which to align our items. We have access to all of the box alignment properties to help us achieve this.
 
-The inline axis is the axis that corresponds to the direction that words in a sentence would run in the writing mode used. Therefore, in a horizontal language such as English or Arabic the inline direction runs horizontally. Should you be in a vertical writing mode the inline axis will run vertically.
+The inline axis is the axis that corresponds to the direction that words in a sentence would run in the writing mode used. Therefore, in a horizontal language such as English or Arabic, the inline direction runs horizontally. Should you be in a vertical writing mode, the inline axis will run vertically.
 
 ![Inline axes are horizontal.](inline_axis.png)
 
-To align things on the inline axis you use the properties that start with `justify-`, {{cssxref("justify-content")}}, {{cssxref("justify-items")}} and {{cssxref("justify-self")}}.
+To align things on the inline axis you use the properties that start with `justify-`: {{cssxref("justify-content")}}, {{cssxref("justify-items")}} and {{cssxref("justify-self")}}.
 
-The block axis crosses the inline axis in the direction that blocks are displayed down the page — for example paragraphs in English are displayed one below the other vertically. This, therefore is the block dimension.
+The block axis crosses the inline axis in the direction that blocks are displayed down the page — for example, paragraphs in English are displayed one below the other vertically. This is the block dimension.
 
 To align things on the block axis you use the properties that start with `align-`, {{cssxref("align-content")}}, {{cssxref("align-items")}} and {{cssxref("align-self")}}.
 
@@ -34,6 +34,8 @@ To align things on the block axis you use the properties that start with `align-
 
 ## Self alignment
 
+These properties deal with aligning the item inside the grid area it is placed into:
+
 - {{cssxref("justify-self")}}
 - {{cssxref("align-self")}}
 - {{cssxref("place-self")}}
@@ -41,50 +43,35 @@ To align things on the block axis you use the properties that start with `align-
 - {{cssxref("align-items")}}
 - {{cssxref("place-items")}}
 
-These properties deal with aligning the item inside the grid area it is placed into. The properties `align-items` and `justify-items` are applied to the grid container and set the `align-self` and `justify-self` properties as a group. This means that you can set alignment for all of your grid items at once, then override any items that need a different alignment by applying the `align-self` or `justify-self` property to the rules for the individual grid items.
+The `*-items` properties, `align-items` and `justify-items`, are applied to the grid container and set alignment for all grid items as a group. The `*-self` properties, `align-self` and `justify-self`, are instead set on grid items. This means that you can set alignment on all grid items, and then override any items that need a different alignment by applying the `align-self` or `justify-self` property to the rules for the individual grid items.
 
-The initial value for `align-self` and `justify-self` is `stretch` so the item will stretch over the entire grid area. The exception to this rule is where the item has an intrinsic {{glossary("aspect ratio")}}, for example an image. In this case the item will be aligned to `start` in both dimensions in order that the image is not distorted.
+The initial value for `align-items` and `justify-items` is `stretch`, and the initial value for `align-self` and `justify-self` is `auto`, so the item will stretch over the entire grid area. The exception to this rule is where the item has an intrinsic {{glossary("aspect ratio")}}, for example an image. In this case the item will be aligned to `start` in both dimensions in order that the image is not distorted.
 
 ## Content alignment
 
+These properties deal with aligning the tracks of the grid when there is extra space to distribute:
+
 - {{cssxref("justify-content")}}
 - {{cssxref("align-content")}}
 - {{cssxref("place-content")}}
 
-These properties deal with aligning the tracks of the grid when there is extra space to distribute. This scenario will occur if the tracks that you have defined total less than the total width of the grid container.
+This scenario will occur if the tracks that you have defined total less than the total width of the grid container.
 
 ## Gap and legacy grid-gap properties
 
-- {{cssxref("row-gap")}}
-- {{cssxref("column-gap")}}
-- {{cssxref("gap")}}
-
-The grid specification originally contained the definition for the properties {{cssxref("row-gap", "grid-row-gap")}}, {{cssxref("column-gap", "grid-column-gap")}} and {{cssxref("gap", "grid-gap")}}. These have since been moved into the Box Alignment specification and renamed to {{cssxref("row-gap")}}, {{cssxref("column-gap")}}, and {{cssxref("gap")}}. This allows them to be used for other layout methods where a gap between items makes sense.
-
-The updated properties have not yet been implemented in all browsers. Therefore, to use the gap properties in grid layout, you should use the `grid-row-gap`, `grid-column-gap` and `grid-gap` versions to ensure full compatibility. You could double up the properties and use both as you would for vendor prefixes.
-
-## Reference
-
-### CSS Properties
+These properties define the spacing between grid items within a grid container:
 
-- {{cssxref("justify-content")}}
-- {{cssxref("align-content")}}
-- {{cssxref("place-content")}}
-- {{cssxref("justify-items")}}
-- {{cssxref("align-items")}}
-- {{cssxref("place-items")}}
-- {{cssxref("justify-self")}}
-- {{cssxref("align-self")}}
-- {{cssxref("place-self")}}
 - {{cssxref("row-gap")}}
 - {{cssxref("column-gap")}}
 - {{cssxref("gap")}}
 
-### Glossary Entries
+The grid specification originally contained the definition for the properties {{cssxref("row-gap", "grid-row-gap")}}, {{cssxref("column-gap", "grid-column-gap")}} and {{cssxref("gap", "grid-gap")}}. These have since been moved into the Box Alignment specification and aliased to {{cssxref("row-gap")}}, {{cssxref("column-gap")}}, and {{cssxref("gap")}}. This allows them to be used for other layout methods where a gap between items makes sense.
 
-- [Cross axis](/en-US/docs/Glossary/Cross_Axis)
-- [Main axis](/en-US/docs/Glossary/Main_Axis)
+## See also
 
-## Guides
+- [Box alignment overview](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment)
+- [Box alignment in flexbox](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment_in_flexbox)
+- [Box alignment in multiple-column layout](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment_in_multi-column_layout)
+- [Box alignment for block, absolutely positioned and table layout](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment_in_block_abspos_tables)
 
 - [Alignment in grid layout](/en-US/docs/Web/CSS/CSS_grid_layout/Box_alignment_in_grid_layout)
diff --git a/files/en-us/web/css/css_box_alignment/box_alignment_in_multi-column_layout/index.md b/files/en-us/web/css/css_box_alignment/box_alignment_in_multi-column_layout/index.md
index 6cc200127aaad36..f1cccb2de0d1649 100644
--- a/files/en-us/web/css/css_box_alignment/box_alignment_in_multi-column_layout/index.md
+++ b/files/en-us/web/css/css_box_alignment/box_alignment_in_multi-column_layout/index.md
@@ -6,33 +6,23 @@ page-type: guide
 
 {{CSSRef}}
 
-The [box alignment](/en-US/docs/Web/CSS/CSS_box_alignment) specification details how alignment works in various layout methods; on this page we explore how Box Alignment works in the context of [multi-column Layout](/en-US/docs/Web/CSS/CSS_multicol_layout). As this page aims to detail things which are specific to Multi-column Layout and Box Alignment, it should be read in conjunction with the main [box alignment](/en-US/docs/Web/CSS/CSS_box_alignment) page which details the common features of Box Alignment across layout methods.
+The [CSS box alignment](/en-US/docs/Web/CSS/CSS_box_alignment) module details how alignment works in various layout methods; in this guide, we explore how box alignment works in the context of [multi-column layout](/en-US/docs/Web/CSS/CSS_multicol_layout). As this guide aims to detail things that are specific to both modules, it should be read in conjunction with the [box alignment overview](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment) guide, which details the common features of box alignment across layout methods.
 
-In multi-column layout the alignment container is the content box of the multicol container. The alignment subject is the column box. The properties which apply to multi-column layouts are detailed below.
-
-> [!NOTE]
-> Multi-column layout predates the box alignment specification. And the properties listed here, while specified for Multicol, may not be supported in browsers.
+In [multi-column layout](/en-US/docs/Web/CSS/CSS_multicol_layout/Basic_concepts), the {{glossary("alignment container")}} is the content box of the multicol container. The {{glossary("alignment subject")}} is the column box. The properties which apply to multi-column layouts are detailed below.
 
 ## align-content and justify-content
 
-The {{cssxref("align-content")}} property applies to the block axis and {{cssxref("justify-content")}} to the inline axis. Any spacing added to the columns due to use of space distribution will be added to the gap between the columns, therefore making the gap larger than might be specified by the {{cssxref("column-gap")}} property.
+The {{cssxref("align-content")}} property applies to the block axis and {{cssxref("justify-content")}} to the inline axis. Any spacing added to the columns due to use of space distribution will be added to the gap between the columns, therefore making the gap larger than might be specified by the {{cssxref("column-gap")}} (or {{cssxref("gap")}} shorthand) property.
 
-Using a value of `justify-content` other than `normal` or `stretch` will cause column boxes to display at the {{cssxref("column-width")}} specified on the multicol container, and the remaining space distributed according to the value of justify-content.
+Using a value of `justify-content` other than `normal` or `stretch` will cause column boxes to display at the {{cssxref("column-width")}} specified on the multicol container, and the remaining space distributed according to the value of `justify-content`.
 
 ## column-gap
 
-The {{cssxref("column-gap")}} property was specified in earlier versions of the multiple-column layout specification, and has now been unified with the gap properties for other layout methods in box alignment. While other layout methods treat the initial value of column-gap as 0 multicol treats it as 1em, as in general you would not want to have no gap between columns.
-
-## Reference
-
-### CSS Properties
-
-- {{cssxref("justify-content")}}
-- {{cssxref("align-content")}}
-- {{cssxref("column-gap")}}
+The {{cssxref("column-gap")}} property was originally specified in the multiple-column layout specification and then later unified with the gap properties for other layout methods in box alignment. While other layout methods treat the initial value of `column-gap` as `0`, multi-column layout treats it as `1em` — you generally want a gap between columns.
 
-### Glossary Entries
+## See also
 
-- [Alignment subject](/en-US/docs/Glossary/Alignment_Subject)
-- [Alignment container](/en-US/docs/Glossary/Alignment_Container)
-- [Fallback alignment](/en-US/docs/Glossary/Fallback_Alignment)
+- [Box alignment overview](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment)
+- [Box alignment in flexbox](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment_in_flexbox)
+- [Box alignment in CSS grid layout](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment_in_grid_layout)
+- [Box alignment for block, absolutely positioned and table layout](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment_in_block_abspos_tables)
diff --git a/files/en-us/web/css/css_box_alignment/index.md b/files/en-us/web/css/css_box_alignment/index.md
index 136ca1e1e6021c3..2a46db4025c4119 100644
--- a/files/en-us/web/css/css_box_alignment/index.md
+++ b/files/en-us/web/css/css_box_alignment/index.md
@@ -7,320 +7,81 @@ spec-urls: https://drafts.csswg.org/css-align/
 
 {{CSSRef}}
 
-The **CSS box alignment** module specifies CSS features that relate to the alignment of boxes in the various CSS box layout models: block layout, table layout, flex layout, and grid layout. The module aims to create a consistent method of alignment across all of CSS. This document details the general concepts found in the specification.
+The **CSS box alignment** module specifies CSS features relating to the alignment of boxes within their containers. It defines the alignment of the various CSS box layout models including block layout, table layout, flexible box layout (flexbox), and grid layout, creating a consistent alignment method across all of CSS.
 
-> [!NOTE]
-> The documentation for each layout method will detail how Box Alignment is applied there.
+The module details alignment terminology, enabling alignment properties to be used in multiple layout modules, rather than limited to a particular layout method.
 
-## Older alignment methods
+Alignment is linked to writing modes in that when we align an item we do not consider whether we are aligning it to the physical dimensions of top, right, bottom, and left. Instead, we describe alignment in terms of the start and end of the particular dimension we are working with. This ensures that alignment works in the same way whichever writing mode the document has.
 
-CSS traditionally had very limited alignment capabilities. We were able to align text using {{cssxref("text-align")}}, center blocks using auto {{cssxref("margin")}}s, and in table or inline-block layouts using the {{cssxref("vertical-align")}} property. Alignment of text is now covered by the [Inline Layout](https://www.w3.org/TR/css-inline-3/) and [CSS Text](https://www.w3.org/TR/css-text-3/) modules, and for the first time in Box Alignment we have full horizontal and vertical alignment capabilities.
+The alignment of text and inline-level content is defined in [CSS text module](/en-US/docs/Web/CSS/CSS_text) and [CSS inline module](/en-US/docs/Web/CSS/CSS_inline_layout), respectively.
 
-If you initially learned [Flexbox](/en-US/docs/Web/CSS/CSS_flexible_box_layout) then you may consider these properties to be part of the flexbox specification, and some of the properties are indeed listed in Level 1 of flexbox. However the specification notes that the Box Alignment specification should be referred to as it may add additional capabilities over what is currently in flexbox.
-
-## Basic examples
-
-The following examples demonstrate how some of the Box Alignment Properties are applied in [Grid](/en-US/docs/Web/CSS/CSS_grid_layout) and [Flexbox](/en-US/docs/Web/CSS/CSS_flexible_box_layout).
-
-### CSS grid layout alignment example
-
-In this example using grid layout, there is extra space in the grid container after laying out the fixed width tracks on the inline (main) axis. This space is distributed using {{cssxref("justify-content")}}. On the block (cross) axis the alignment of the items inside their grid areas is controlled with {{cssxref("align-items")}}. The first item overrides the `align-items` value set on the group by setting {{cssxref("align-self")}} to `center`.
-
-```html live-sample___grid-align-items
-<div class="box">
-  <div>One</div>
-  <div>Two</div>
-  <div>Three <br />has <br />extra <br />text</div>
-  <div>Four</div>
-  <div>Five</div>
-  <div>Six</div>
-</div>
-```
-
-```css hidden live-sample___grid-align-items
-body {
-  font: 1.2em sans-serif;
-}
-
-.box {
-  border: 2px dotted rgb(96 139 168);
-}
-
-.box > * {
-  padding: 20px;
-  border: 2px solid rgb(96 139 168);
-  border-radius: 5px;
-  background-color: rgb(96 139 168 / 0.2);
-}
-```
-
-```css live-sample___grid-align-items
-.box {
-  display: grid;
-  grid-template-columns: 120px 120px 120px;
-  align-items: start;
-  justify-content: space-between;
-}
-
-.box :first-child {
-  align-self: center;
-}
-```
-
-{{EmbedLiveSample("grid-align-items", "", "200px")}}
-
-### Flexbox Alignment Example
-
-In this example, three flex items are aligned on the main axis using `justify-content` and on the Cross Axis using `align-items`. The first item overrides the `align-items` set on the group by setting `align-self` to `center`.
-
-```html live-sample___flex-align-items
-<div class="box">
-  <div>One</div>
-  <div>Two</div>
-  <div>Three <br />has <br />extra <br />text</div>
-</div>
-```
-
-```css hidden live-sample___flex-align-items
-body {
-  font: 1.2em sans-serif;
-}
-
-.box {
-  border: 2px dotted rgb(96 139 168);
-}
-
-.box > * {
-  padding: 20px;
-  border: 2px solid rgb(96 139 168);
-  border-radius: 5px;
-  background-color: rgb(96 139 168 / 0.2);
-}
-```
-
-```css live-sample___flex-align-items
-.box {
-  display: flex;
-  align-items: flex-start;
-  justify-content: space-between;
-}
-
-.box :first-child {
-  align-self: center;
-}
-```
-
-{{EmbedLiveSample("flex-align-items")}}
-
-## Key concepts and terminology
-
-The specification details some alignment terminology to make it easier to discuss these alignment properties outside their implementation within a particular layout method. There are also some key concepts which are common to all layout methods.
-
-### Relationship to writing modes
-
-Alignment is linked to writing modes in that when we align an item we do not consider whether we are aligning it to the physical dimensions of top, right, bottom and left. Instead we describe alignment in terms of the start and end of the particular dimension we are working with. This ensures that alignment works in the same way whichever writing mode the document has.
-
-### Two dimensions of alignment
-
-When using the box alignment properties you will align content on one of two axes — the inline (or main) axis, and the block (or cross) axis. The inline axis is the axis along which words in a sentence flow in the writing mode being used — for English, for example, the inline axis is horizontal. The block axis is the axis along which blocks, such as paragraph elements, are laid out and it runs across the Inline axis.
-
-![Inline axis is the left / right, or horizontal, direction. Block axis is vertical, or top / bottom.](two-axes.png)
-
-When aligning items on the inline axis you will use the properties which begin with `justify-`:
-
-- {{cssxref("justify-items")}}
-- {{cssxref("justify-self")}}
-- {{cssxref("justify-content")}}
+## Reference
 
-When aligning items on the block axis you will use the properties that begin `align-`:
+### CSS Properties
 
+- {{cssxref("align-content")}}
 - {{cssxref("align-items")}}
 - {{cssxref("align-self")}}
-- {{cssxref("align-content")}}
-
-Flexbox adds an additional complication in that the above is true when {{cssxref("flex-direction")}} is set to `row`. The properties are swapped when flexbox is set to `column`. Therefore, when working with flexbox it is easier to think about the main and cross axis rather than inline and block. The `justify-` properties are always used to align on the main axis, the `align-` properties on the cross axis.
-
-### The alignment subject
-
-The **alignment subject** is the thing that is being aligned. For `justify-self` or `align-self`, or when setting these values as a group with `justify-items` or `align-items`, this will be the margin box of the element that this property is being used on. The `justify-content` and `align-content` properties differ per layout method.
-
-### The alignment container
-
-The **alignment container** is the box the subject is being aligned inside. This will typically be the alignment subject's containing block. An alignment container may contain one or many alignment subjects.
-
-The below image shows an alignment container with two alignment subjects inside.
-
-![A box containing two rectangles of the same width but different heights. The two rectangles are top aligned, meaning they both have their top lines about 10px inside the top of the box in which they are contained.](align-container-subjects.png)
-
-### Fallback alignment
-
-If you set an alignment that cannot be fulfilled, then the **fallback alignment** will come into play and deal with the available space. This fallback alignment is specified individually for each layout method and detailed on the page for that method.
-
-## Types of alignment
-
-There are three different types of alignment that the specification details; these use keyword values.
-
-- **Positional alignment**: specifying the position of an alignment subject with relation to its alignment container.
-- **Baseline alignment**: These keywords define alignment as a relationship among the baselines of multiple alignment subjects within an alignment context.
-- **Distributed alignment**: These keywords define alignment as a distribution of space among alignment subjects.
-
-### Positional alignment keyword values
-
-The following values are defined for positional alignment, and can be used as values for content alignment with `justify-content` and `align-content` and also for self alignment with `justify-self` and `align-self`.
-
-- `center`
-- `start`
-- `end`
-- `self-start`
-- `self-end`
-- `flex-start` for flexbox only
-- `flex-end` for flexbox only
-- `left`
-- `right`
-
-Other than the physical values of `left` and `right`, which relate to physical attributes of the screen, all of the other values are logical values and relate to the writing mode of the content.
-
-For example, when working in CSS grid layout, if you are working in English and set `justify-content` to `start` this will move the items in the inline dimension to the start, which will be the left as sentences in English start on the left. If you were using Arabic, a right to left language, then the same value of `start` would result in the items moving to the right, as sentences in Arabic start on the right-hand side of the page.
-
-Both of these examples have `justify-content: start`, however the location of start changes according to the writing mode.
-
-![There are two boxes, each with 3 children of differing heights but similar widths. The first box has three children with the letters A, B, and C. These three boxes are all aligned to the left. The second box has three children with arabic letters in them. Those three boxes are all aligned to the right.](writing-mode-start.png)
-
-### Baseline alignment
-
-The Baseline alignment keywords are used to align the baselines of boxes across a group of alignment subjects. They can be used as values for content alignment with `justify-content` and `align-content` and also for self alignment with `justify-self` and `align-self`.
-
-- `baseline`
-- `first baseline`
-- `last baseline`
-
-Baseline content alignment — specifying a baseline alignment value for `justify-content` or `align-content` — works in layout methods that lay items out in rows. The alignment subjects are baseline aligned against each other by adding padding inside the boxes.
-
-Baseline self alignment shifts the boxes to align by baseline by adding a margin outside the boxes. Self alignment is when using `justify-self` or `align-self`, or when setting these values as a group with `justify-items` and `align-items`.
-
-### Distributed alignment
-
-The **distributed alignment keywords** are used with the `align-content` and `justify-content` properties. These keywords define what happens to any additional space after alignment subjects have been displayed. The values are as follows:
-
-- `stretch`
-- `space-between`
-- `space-around`
-- `space-evenly`
-
-For example, in Flex Layout items are aligned with `flex-start` initially. Working in a horizontal top to bottom writing mode such as English, with `flex-direction` as `row` the items start on the far left and any available space after displaying the items is placed after the items.
-
-![Three rectangles of different widths are inside a box. They are all aligned to the left side of the containing box, with about 10px between them, and 10px between the left side of the first rectangle and the parent container.](justify-content-start.png)
-
-If you set `justify-content: space-between` on the flex container, the available space is now shared out and placed between the items.
-
-![Three rectangles of different widths are inside a box. The first rectangle is aligned to the left side of the containing box, the third rectangle is aligned right, and the middle rectangle is equally spaced between the first and last.](justify-content-space-between.png)
-
-There needs to be space available in the dimension you wish to align the items in, in order for these keywords to take effect. With no space, there is nothing to distribute.
-
-## Overflow alignment
-
-The `safe` and `unsafe` keywords help define behavior when an alignment subject is larger than the alignment container. The `safe` keyword will align to `start` in the case of a specified alignment causing an overflow, the aim being to avoid "data loss" where part of the item is outside the boundaries of the alignment container and can't be scrolled to.
-
-If you specify `unsafe` then the alignment will be honoured even if it would cause such data loss.
-
-## Gaps between boxes
-
-The box alignment specification also includes the `gap`, `row-gap`, and `column-gap` properties. These properties enable the setting of a consistent gap between items in a row or column, in any layout method which has items arranged in this way.
-
-The `gap` property is a shorthand for `row-gap` and `column-gap`, which allows us to set these properties at once:
-
-- {{cssxref("row-gap")}}
 - {{cssxref("column-gap")}}
 - {{cssxref("gap")}}
+- {{cssxref("justify-content")}}
+- {{cssxref("justify-items")}}
+- {{cssxref("justify-self")}}
+- {{cssxref("place-content")}}
+- {{cssxref("place-items")}}
+- {{cssxref("place-self")}}
+- {{cssxref("row-gap")}}
 
-In the below example, a grid layout uses the `gap` shorthand to set a `10px` gap between row tracks, and a `2em` gap between column tracks.
-
-```html live-sample___grid-gap
-<div class="box">
-  <div>One</div>
-  <div>Two</div>
-  <div>Three</div>
-  <div>Four</div>
-  <div>Five</div>
-  <div>Six</div>
-</div>
-```
+### Data types
 
-```css hidden live-sample___grid-gap
-body {
-  font: 1.2em sans-serif;
-}
+- {{cssxref("baseline-position")}}
+- {{cssxref("content-distribution")}}
+- {{cssxref("content-position")}}
+- {{cssxref("overflow-position")}}
+- {{cssxref("self-position")}}
 
-.box {
-  border: 2px dotted rgb(96 139 168);
-}
+### Terms and definitions
 
-.box > * {
-  padding: 20px;
-  border: 2px solid rgb(96 139 168);
-  border-radius: 5px;
-  background-color: rgb(96 139 168 / 0.2);
-}
-```
+- {{Glossary("Alignment container")}}
+- {{Glossary("Alignment subject")}}
+- [Baseline alignment](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment#baseline_alignment)
+- [Distributed alignment](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment#distributed_alignment)
+- {{Glossary("Fallback alignment")}}
+- [Positional alignment](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment#positional_alignment)
 
-```css live-sample___grid-gap
-.box {
-  display: grid;
-  grid-template-columns: 1fr 1fr 1fr;
-  gap: 10px 2em;
-}
+## Guides
 
-.box :first-child {
-  align-self: center;
-}
-```
+- [Box alignment overview](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment)
 
-{{EmbedLiveSample("grid-gap")}}
+  - : Overview of the general concepts found in the CSS box alignment module.
 
-> [!NOTE]
-> The early grid implementation included `-gap` properties prefixed with `grid-`. All browsers now support the unprefixed properties, though you may see the following legacy properties in examples and tutorials: {{cssxref("row-gap", "grid-row-gap")}}, {{cssxref("column-gap", "grid-column-gap")}}, and {{cssxref("gap", "grid-gap")}}. The prefixed versions will be maintained as an alias of the unprefixed ones.
+- [Box alignment in flexbox](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment_in_flexbox)
 
-Be aware that other things may increase the visual gap displayed, for example using the space distribution keywords or adding margins to items.
+  - : How box alignment works in the context of flexbox.
 
-## Pages detailing individual alignment properties
+- [Box alignment in CSS grid layout](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment_in_grid_layout)
 
-As the CSS box alignment properties are implemented differently depending on the specification they interact with, refer to the following pages for each layout type for details of how to use the alignment properties with it:
+  - : How box alignment works in the context of grid layout.
 
-- [Box alignment in flexbox](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment_in_flexbox)
-- [Box alignment in CSS grid layout](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment_in_grid_layout)
 - [Box alignment in multiple-column layout](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment_in_multi-column_layout)
-- [Box alignment for block, absolutely positioned and table layout](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment_in_block_abspos_tables)
 
-## Reference
+  - : How box alignment works in the context of multi-column layout.
 
-### CSS Properties
+- [Box alignment for block, absolutely positioned and table layout](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment_in_block_abspos_tables)
 
-- {{cssxref("justify-content")}}
-- {{cssxref("align-content")}}
-- {{cssxref("place-content")}}
-- {{cssxref("justify-items")}}
-- {{cssxref("align-items")}}
-- {{cssxref("place-items")}}
-- {{cssxref("justify-self")}}
-- {{cssxref("align-self")}}
-- {{cssxref("place-self")}}
-- {{cssxref("row-gap")}}
-- {{cssxref("column-gap")}}
-- {{cssxref("gap")}}
+  - : How box alignment works in the context of block layout, including floated, positioned, and table elements.
 
-### Glossary Entries
+## Related concepts
 
+- {{cssxref("alignment-baseline")}}
+- {{cssxref("dominant-baseline")}}
+- {{cssxref("grid-column-gap")}}
+- {{cssxref("grid-gap")}}
+- {{cssxref("grid-row-gap")}}
+- {{cssxref("scroll-snap-align")}}
+- SVG {{SVGAttr("dominant-baseline")}} attribute
 - {{Glossary("Cross axis")}}
 - {{Glossary("Main axis")}}
-- {{Glossary("Alignment container")}}
-- {{Glossary("Alignment subject")}}
-- {{Glossary("Fallback alignment")}}
-
-## Guides
-
-- [Basic concepts of flexbox](/en-US/docs/Web/CSS/CSS_flexible_box_layout/Basic_concepts_of_flexbox)
-- [Aligning items in a flex container](/en-US/docs/Web/CSS/CSS_flexible_box_layout/Aligning_items_in_a_flex_container)
-- [Box alignment in CSS grid layouts](/en-US/docs/Web/CSS/CSS_grid_layout/Box_alignment_in_grid_layout)
 
 ## Specifications
 
@@ -328,6 +89,9 @@ As the CSS box alignment properties are implemented differently depending on the
 
 ## See also
 
+- [Basic concepts of flexbox](/en-US/docs/Web/CSS/CSS_flexible_box_layout/Basic_concepts_of_flexbox)
+- [Aligning items in a flex container](/en-US/docs/Web/CSS/CSS_flexible_box_layout/Aligning_items_in_a_flex_container)
+- [Box alignment in CSS grid layouts](/en-US/docs/Web/CSS/CSS_grid_layout/Box_alignment_in_grid_layout)
 - [CSS display](/en-US/docs/Web/CSS/CSS_display) module
-- [CSS flex layout](/en-US/docs/Web/CSS/CSS_flexible_box_layout) module
+- [CSS flexible box layout](/en-US/docs/Web/CSS/CSS_flexible_box_layout) module
 - [CSS grid layout](/en-US/docs/Web/CSS/CSS_grid_layout) module
diff --git a/files/en-us/web/css/css_flexible_box_layout/aligning_items_in_a_flex_container/index.md b/files/en-us/web/css/css_flexible_box_layout/aligning_items_in_a_flex_container/index.md
index e462ae603d42677..83687c0cdee7a4f 100644
--- a/files/en-us/web/css/css_flexible_box_layout/aligning_items_in_a_flex_container/index.md
+++ b/files/en-us/web/css/css_flexible_box_layout/aligning_items_in_a_flex_container/index.md
@@ -190,7 +190,7 @@ You can try this out in the example below, which has a flex container with `flex
 
 ## Aligning content on the cross axis with the `align-content` property
 
-So far, we have focused on aligning items or an individual items inside the area defined by a {{glossary("flex_container")}} containing a single line of flex items. When flex items are allowed to wrap across multiple lines, the {{cssxref("align-content")}} property can be used to control the distribution of space between the lines, also known as **packing flex lines**.
+So far, we have focused on aligning items or individual items inside the area defined by a {{glossary("flex container")}} containing a single line of flex items. When flex items are allowed to wrap across multiple lines, the {{cssxref("align-content")}} property can be used to control the distribution of space between the lines, also known as **packing flex lines**.
 
 For `align-content` to have an effect, the cross axis dimension (the height in this case) of the flex container must be greater than needed to display the items. It then works on all the items as a set. The `align-content` values dictate what happens with the extra available space and the alignment of the entire set of items within it.
 
@@ -307,7 +307,7 @@ In our initial example with `display: flex` on the container, the items display
 
 ![Three items, each 100 pixels wide in a 500 pixel container. The available space is at the end of the items.](align6.png)
 
-The `baseline` values aren't relevant in this dimension. Otherwise, `justify-content` property accepts the same values as `align-content`.
+The `baseline` values aren't relevant in this dimension. Otherwise, the `justify-content` property accepts the same values as `align-content`.
 
 - `justify-content: flex-start`
 - `justify-content: flex-end`
@@ -514,7 +514,7 @@ In this live example, the flex items are arranged in a row with the basic flex v
 To create a gap between flex items, use the {{cssxref("gap")}}, {{cssxref("column-gap")}}, and {{cssxref("row-gap")}} properties. The {{cssxref("column-gap")}} property creates gaps between items in a row. The {{cssxref("row-gap")}} property creates gaps between flex lines when you have {{cssxref("flex-wrap")}} set to `wrap`.
 
 The {{cssxref("gap")}} property is a shorthand that sets both `row-gap` and `column-gap`.
-The gap between flex items or between flex line depends on the direction. If the {{cssxref("flex-direction")}} property creates rows, the first value defines the gap between flex lines, and the second value defines the gap between items within each line. With columns (when `flex-direction` is set to `column` or `column-reverse`), the first value defines the gap between flex items, and the second value defines the gaps between flex lines.
+The gaps between flex items or flex lines depend on the direction. If the {{cssxref("flex-direction")}} property creates rows, the first value defines the gap between flex lines, and the second value defines the gap between items within each line. With columns (when `flex-direction` is set to `column` or `column-reverse`), the first value defines the gap between flex items, and the second value defines the gaps between flex lines.
 
 ```html live-sample___gap
 <div class="box">
diff --git a/files/en-us/web/css/css_flexible_box_layout/basic_concepts_of_flexbox/index.md b/files/en-us/web/css/css_flexible_box_layout/basic_concepts_of_flexbox/index.md
index fc85d54f56c87f0..f834f49fe7bbdd4 100644
--- a/files/en-us/web/css/css_flexible_box_layout/basic_concepts_of_flexbox/index.md
+++ b/files/en-us/web/css/css_flexible_box_layout/basic_concepts_of_flexbox/index.md
@@ -292,7 +292,7 @@ Using `flex: auto` is the same as using `flex: 1 1 auto`; this is similar to `fl
 
 Using `flex: none` will create fully inflexible flex items. It is as if you wrote `flex: 0 0 auto`. The items cannot grow or shrink and will be laid out using flexbox with a `flex-basis` of `auto`.
 
-The shorthand you often see in tutorials is `flex: 1` or `flex: 2` and so on. This is the same as writing `flex: 1 1 0` or `flex: 2 1 0` and so on, respectively. The items can grow and shrink from a `flex-basis` of `0`.
+The shorthand you often see in tutorials is `flex: 1` or `flex: 2` and so on. This is the same as writing `flex: 1 1 0` or `flex: 2 1 0` and so on, respectively. The items get minimum size due to `flex-basis: 0` and then proportionally grow to fill the available space. In this case, the `flex-shrink` value of `1` is redundant because the items start with minimum size — they're not given any size that could cause them to overflow the flex container.
 
 Try these shorthand values in the live sample below.
 
diff --git a/files/en-us/web/css/css_flexible_box_layout/index.md b/files/en-us/web/css/css_flexible_box_layout/index.md
index d80f2b0a57309f1..1cd2e2fa998f5e3 100644
--- a/files/en-us/web/css/css_flexible_box_layout/index.md
+++ b/files/en-us/web/css/css_flexible_box_layout/index.md
@@ -121,5 +121,6 @@ body {
 
 ## See also
 
+- [CSS grid layout](/en-US/docs/Web/CSS/CSS_grid_layout) module
 - [CSS writing modes](/en-US/docs/Web/CSS/CSS_writing_modes) module
 - [Using the multi-keyword syntax with CSS display](/en-US/docs/Web/CSS/display/multi-keyword_syntax_of_display)
diff --git a/files/en-us/web/css/css_grid_layout/basic_concepts_of_grid_layout/index.md b/files/en-us/web/css/css_grid_layout/basic_concepts_of_grid_layout/index.md
index 929807521258323..a2dfa522f8e0844 100644
--- a/files/en-us/web/css/css_grid_layout/basic_concepts_of_grid_layout/index.md
+++ b/files/en-us/web/css/css_grid_layout/basic_concepts_of_grid_layout/index.md
@@ -10,7 +10,7 @@ page-type: guide
 
 ## What is a grid?
 
-A grid is a set of intersecting horizontal and vertical lines defining columns and rows. Elements can be placed onto the grid within these column and row lines. CSS grid layout has the following features:
+A grid is a set of intersecting horizontal and vertical lines defining rows and columns. Elements can be placed onto the grid within these column and row lines. CSS grid layout has the following features:
 
 ### Fixed and flexible track sizes
 
diff --git a/files/en-us/web/css/css_overflow/index.md b/files/en-us/web/css/css_overflow/index.md
index 59a8120532db5b6..b94c2a392155219 100644
--- a/files/en-us/web/css/css_overflow/index.md
+++ b/files/en-us/web/css/css_overflow/index.md
@@ -3,8 +3,8 @@ title: CSS overflow
 slug: Web/CSS/CSS_overflow
 page-type: css-module
 spec-urls:
-  - https://drafts.csswg.org/css-overflow-3
-  - https://drafts.csswg.org/css-overflow-4
+  - https://drafts.csswg.org/css-overflow-3/
+  - https://drafts.csswg.org/css-overflow-4/
 ---
 
 {{CSSRef}}
diff --git a/files/en-us/web/css/flex-basis/index.md b/files/en-us/web/css/flex-basis/index.md
index d0a842d09136451..2524fde44c6ef5d 100644
--- a/files/en-us/web/css/flex-basis/index.md
+++ b/files/en-us/web/css/flex-basis/index.md
@@ -176,7 +176,7 @@ This example demonstrates the difference between a `flex-basis` of `0` versus a
 
 #### HTML
 
-We include two same-structure flex containers. These which will be styled similarly, except for their `flex-basis` values. The containers each have two children: a heading `<div>` and a `<section>`. The `<section>` element has a content `<div>` child, which will not be set as a flex item but will be given a height.
+We include two same-structure flex containers, which will be styled similarly except for their `flex-basis` values. The containers each have two children: a heading `<div>` and a `<section>`. The `<section>` element has a content `<div>` child, which will not be set as a flex item but will be given a height.
 
 ```html
 <div class="container basis-0">
@@ -197,7 +197,7 @@ We include two same-structure flex containers. These which will be styled simila
 
 #### CSS
 
-We style the containers as inline flex containers that will appear side by side to better enable comparing them. We set the `flex-direction` to the column. The first container's flex items have a `flex-basis` value of `0` and the second container's flex item have a `flex-basis` value of `0%`. Neither the flex containers nor their flex items have a height explicitly set, but the heights of `section` elements can not exceed `200px` and their children have height `300px`.
+We style the containers as inline flex containers that will appear side by side to better enable comparing them. We set the `flex-direction` to `column`. The first container's flex items have a `flex-basis` value of `0`, while the second container's flex items have a `flex-basis` value of `0%`. Neither the flex containers nor their flex items have a height explicitly set, but the heights of `section` elements cannot exceed `200px` and their children have a height of `300px`.
 
 ```css
 .container {
diff --git a/files/en-us/web/css/justify-items/index.md b/files/en-us/web/css/justify-items/index.md
index 2874c0b27f5805d..d7b4619668dc5c4 100644
--- a/files/en-us/web/css/justify-items/index.md
+++ b/files/en-us/web/css/justify-items/index.md
@@ -75,7 +75,7 @@ This property can take one of four different forms:
     - In absolutely-positioned layouts, the keyword behaved like `start` on _replaced_ absolutely-positioned boxes, and as `stretch` on _all other_ absolutely-positioned boxes.
     - In table cell layouts, this keyword has no meaning as this property is _ignored_.
     - In flexbox layouts, this keyword has no meaning as this property is _ignored._
-    - In grid layouts, this keyword leads to a behavior similar to the one of `stretch`, except for boxes with an aspect ratio or an intrinsic sizes where it behaves like `start`.
+    - In grid layouts, this keyword leads to a behavior similar to the one of `stretch`, except for boxes with an aspect ratio or an intrinsic size where it behaves like `start`.
 - `start`
   - : The item is packed flush to each other toward the start edge of the alignment container in the appropriate axis.
 - `end`
diff --git a/files/en-us/web/css/justify-self/index.md b/files/en-us/web/css/justify-self/index.md
index bff8949755cce3c..735151fd70670a0 100644
--- a/files/en-us/web/css/justify-self/index.md
+++ b/files/en-us/web/css/justify-self/index.md
@@ -77,7 +77,7 @@ This property can take one of three different forms:
     - In absolutely-positioned layouts, the keyword behaves like `start` on _replaced_ absolutely-positioned boxes, and as `stretch` on _all other_ absolutely-positioned boxes.
     - In table cell layouts, this keyword has no meaning as this property is _ignored_.
     - In flexbox layouts, this keyword has no meaning as this property is _ignored._
-    - In grid layouts, this keyword leads to a behavior similar to the one of `stretch`, except for boxes with an aspect ratio or an intrinsic sizes where it behaves like `start`.
+    - In grid layouts, this keyword leads to a behavior similar to the one of `stretch`, except for boxes with an aspect ratio or an intrinsic size where it behaves like `start`.
 
 - `start`
   - : The item is packed flush to each other toward the start edge of the alignment container in the appropriate axis.
diff --git a/files/en-us/web/css/order/index.md b/files/en-us/web/css/order/index.md
index 2a86349fb6dd375..33506e12dc81a6b 100644
--- a/files/en-us/web/css/order/index.md
+++ b/files/en-us/web/css/order/index.md
@@ -30,9 +30,9 @@ order: revert-layer;
 order: unset;
 ```
 
-Since `order` is only meant to affect the _visual order_ of elements and not their logical or tab order. `order` must not be used on non-visual media such as [speech](/en-US/docs/Web/CSS/@media#speech).
+Since `order` is only meant to affect the _visual order_ of elements and not their logical or tab order, it must not be used on non-visual media such as [speech](/en-US/docs/Web/CSS/@media#speech).
 
-Defined in the [CSS display](/en-US/docs/Web/CSS/CSS_display) module, this property impacts only grid and flex items. When `order` is set on an element whose parent's {{cssxref("display")}} property is not creating a flex or grid container, the `order` property has no effect.
+Defined in the [CSS display](/en-US/docs/Web/CSS/CSS_display) module, this property impacts only grid and flex items. When `order` is set on an element whose parent's {{cssxref("display")}} property is not creating a flex or grid container, it has no effect.
 
 ### Values
 
diff --git a/files/en-us/web/css/overflow-position/index.md b/files/en-us/web/css/overflow-position/index.md
new file mode 100644
index 000000000000000..a8202bb6872cbc0
--- /dev/null
+++ b/files/en-us/web/css/overflow-position/index.md
@@ -0,0 +1,46 @@
+---
+title: <overflow-position>
+slug: Web/CSS/overflow-position
+page-type: css-type
+browser-compat: css.types.overflow-position
+---
+
+{{CSSRef}}
+
+The **`<overflow-position>`** {{glossary("enumerated")}} value type defines how an alignment subject that is larger than its alignment container will overflow that container. For example, if centered items are wider than their container, the overflow may be displayed beyond the viewport's start edge, which can't be scrolled to. The `<overflow-position>` value defines whether the alignment mode should be overridden to ensure the content is visible (`safe`) or if the alignment mode must be adhered to (`unsafe`).
+
+This data type is valid for the {{cssxref("align-content")}}, {{cssxref("align-items")}}, {{cssxref("align-self")}}, {{cssxref("justify-items")}} and {{cssxref("justify-self")}} properties as well as the {{cssxref("place-content")}}, {{cssxref("place-items")}}, and {{cssxref("place-self")}} shorthand properties.
+If omitted, the default overflow alignment is a blend of `safe` and `unsafe`.
+
+## Syntax
+
+```plain
+<overflow-position> = unsafe | safe
+```
+
+## Values
+
+The following keyword values are represented by the `<overflow-position>` grammar term:
+
+- `safe`
+
+  - : If the size of the {{glossary("alignment subject")}} overflows the {{glossary("alignment container")}}, the alignment subject is instead aligned as if the alignment mode were `start`.
+
+- `unsafe`
+  - : Regardless of the relative sizes of the alignment subject and alignment container, the given alignment value is honored.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- Properties that use this data type: {{cssxref("align-content")}}, {{cssxref("align-items")}}, {{cssxref("align-self")}}, {{cssxref("justify-content")}} {{cssxref("justify-items")}}, {{cssxref("justify-self")}}, {{cssxref("place-content")}}, {{cssxref("place-items")}}, and {{cssxref("place-self")}}
+- Other box alignment data types: {{cssxref("content-distribution")}}, {{cssxref("content-position")}}, {{cssxref("baseline-position")}}, and {{cssxref("self-position")}}
+- [CSS box alignment](/en-US/docs/Web/CSS/CSS_box_alignment) module
+- [CSS flexible box layout](/en-US/docs/Web/CSS/CSS_flexible_box_layout) module
+- [CSS grid layout](/en-US/docs/Web/CSS/CSS_grid_layout) module
diff --git a/files/en-us/web/css/place-self/index.md b/files/en-us/web/css/place-self/index.md
index 45bb89dccc9d189..5502b2b40f00d2c 100644
--- a/files/en-us/web/css/place-self/index.md
+++ b/files/en-us/web/css/place-self/index.md
@@ -58,7 +58,7 @@ place-self: unset;
     - In absolutely-positioned layouts, the keyword behaves like `start` on _replaced_ absolutely-positioned boxes, and as `stretch` on _all other_ absolutely-positioned boxes.
     - In static position of absolutely-positioned layouts, the keyword behaves as `stretch`.
     - For flex items, the keyword behaves as `stretch`.
-    - For grid items, this keyword leads to a behavior similar to the one of `stretch`, except for boxes with an {{glossary("aspect ratio")}} or an intrinsic sizes where it behaves like `start`.
+    - For grid items, this keyword leads to a behavior similar to the one of `stretch`, except for boxes with an {{glossary("aspect ratio")}} or an intrinsic size where it behaves like `start`.
     - The property doesn't apply to block-level boxes, and to table cells.
 
 - `self-start`
diff --git a/files/en-us/web/css/scroll-snap-align/index.md b/files/en-us/web/css/scroll-snap-align/index.md
index 1c414d91b4498ab..ef34a380d869635 100644
--- a/files/en-us/web/css/scroll-snap-align/index.md
+++ b/files/en-us/web/css/scroll-snap-align/index.md
@@ -7,7 +7,7 @@ browser-compat: css.properties.scroll-snap-align
 
 {{CSSRef}}
 
-The `scroll-snap-align` property specifies the box's snap position as an alignment of its [snap area](/en-US/docs/Glossary/Scroll_snap#snap_area) (as the alignment subject) within its snap container's snap port (as the alignment container).
+The `scroll-snap-align` property specifies the box's snap position as an alignment of its [snap area](/en-US/docs/Glossary/Scroll_snap#snap_area) (as the {{glossary("alignment subject")}}) within its snap container's snap port (as the {{glossary("alignment container")}}).
 
 {{EmbedInteractiveExample("pages/css/scroll-snap-align.html")}}
 
diff --git a/files/en-us/web/css/self-position/index.md b/files/en-us/web/css/self-position/index.md
new file mode 100644
index 000000000000000..82970a3231d3909
--- /dev/null
+++ b/files/en-us/web/css/self-position/index.md
@@ -0,0 +1,54 @@
+---
+title: <self-position>
+slug: Web/CSS/self-position
+page-type: css-type
+browser-compat: css.types.self-position
+---
+
+{{CSSRef}}
+
+The **`<self-position>`** {{glossary("enumerated")}} value data type is used by the {{cssxref("justify-self")}} and {{cssxref("align-self")}} properties, and the {{cssxref("place-self")}} shorthand, to align the box within its alignment container. It is also used by the {{cssxref("justify-items")}} and {{cssxref("align-items")}} properties, and the {{cssxref("place-items")}} shorthand, to specify default values for `justify-self` and `align-self`.
+
+## Syntax
+
+```plain
+<self-position> = center | start | end | self-start | self-end | flex-start | flex-end
+```
+
+## Values
+
+The following keyword values are represented by the `<self-position>` grammar term:
+
+- `center`
+  - : Centers the {{glossary("alignment subject")}} within its {{glossary("alignment container")}}.
+- `start`
+  - : Aligns the alignment subject flush with the alignment container's start edge.
+- `end`
+  - : Aligns the alignment subject flush with the alignment container's end edge.
+- `self-start`
+  - : Aligns the alignment subject flush with the edge of the alignment container corresponding to the alignment subject's start side.
+- `self-end`
+  - : Aligns the alignment subject flush with the edge of the alignment container corresponding to the alignment subject's end side.
+- `flex-start`
+  - : In flex layout, aligns the alignment subject flush with the edge of the alignment container corresponding to the flex container's main-start or cross-start side, as appropriate. It is identical to `start` for layout modes other than flex layout.
+- `flex-end`
+  - : In flex layout, aligns the alignment subject flush with the edge of the alignment container corresponding to the flex container's main-end or cross-end side, as appropriate. Identical to `end` for layout modes other than flex layout.
+
+> [!NOTE]
+> The `left` and `right` keywords are excluded from `<self-position>`, despite being valid positional alignment values for the `justify-*` properties ({{cssxref("justify-content")}}, {{cssxref("justify-self")}}, and {{cssxref("justify-items")}}), because they are not allowed in the `align-*` properties ({{cssxref("align-content")}}, {{cssxref("align-self")}}, and {{cssxref("align-items")}}). They are instead explicitly included in the `justify-*` properties' grammars.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- Properties that use this data type: {{cssxref("align-self")}}, {{cssxref("justify-self")}}, {{cssxref("place-self")}}, {{cssxref("align-items")}}, {{cssxref("justify-items")}}, {{cssxref("place-items")}}
+- Other box alignment data types: {{cssxref("baseline-position")}}, {{cssxref("content-distribution")}}, {{cssxref("overflow-position")}}, and {{cssxref("content-position")}}
+- [CSS box alignment](/en-US/docs/Web/CSS/CSS_box_alignment) module
+- [CSS flexible box layout](/en-US/docs/Web/CSS/CSS_flexible_box_layout) module
+- [CSS grid layout](/en-US/docs/Web/CSS/CSS_grid_layout) module
diff --git a/files/en-us/web/css/writing-mode/index.md b/files/en-us/web/css/writing-mode/index.md
index 163427922e34acd..85de61f2926558f 100644
--- a/files/en-us/web/css/writing-mode/index.md
+++ b/files/en-us/web/css/writing-mode/index.md
@@ -20,6 +20,8 @@ This property specifies the _block flow direction_, which is the direction in wh
 writing-mode: horizontal-tb;
 writing-mode: vertical-rl;
 writing-mode: vertical-lr;
+writing-mode: sideways-rl;
+writing-mode: sideways-lr;
 
 /* Global values */
 writing-mode: inherit;
@@ -51,7 +53,7 @@ The `writing-mode` property is specified as one of the values listed below. The
   - : Deprecated except for SVG1 documents. For CSS, use `horizontal-tb` instead.
 - `tb`
   - : Deprecated except for SVG1 documents. For CSS, use `vertical-lr` instead.
-- `tb-lr`
+- `tb-lr` {{Deprecated_Inline}}
   - : Deprecated except for SVG1 documents. For CSS, use `vertical-lr` instead.
 - `tb-rl`
   - : Deprecated except for SVG1 documents. For CSS, use `vertical-rl` instead.
diff --git a/files/en-us/web/html/date_and_time_formats/index.md b/files/en-us/web/html/date_and_time_formats/index.md
index 37b11741315b27b..bd5e6ba08279a11 100644
--- a/files/en-us/web/html/date_and_time_formats/index.md
+++ b/files/en-us/web/html/date_and_time_formats/index.md
@@ -430,6 +430,6 @@ Why worry about the Y10K problem if it is going to happen many centuries after y
 - {{HTMLElement("input")}}
 - {{HTMLElement("ins")}} and {{HTMLElement("del")}}: see the `datetime` attribute, which specifies either a date or a local date and time at which the content was inserted or deleted
 - [The ISO 8601 specification](https://www.iso.org/iso-8601-date-and-time-format.html)
-- [Numbers and Dates](/en-US/docs/Web/JavaScript/Guide/Numbers_and_dates) in the [JavaScript Guide](/en-US/docs/Web/JavaScript/Guide)
+- [Representing dates & times](/en-US/docs/Web/JavaScript/Guide/Representing_dates_times) in the [JavaScript Guide](/en-US/docs/Web/JavaScript/Guide)
 - The JavaScript {{jsxref("Date")}} object
 - The [`Intl.DateTimeFormat`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat) object for formatting dates and times for a given locale
diff --git a/files/en-us/web/html/element/input/submit/index.md b/files/en-us/web/html/element/input/submit/index.md
index 0c51a87c7df5300..1f6abc9ca68bb6b 100644
--- a/files/en-us/web/html/element/input/submit/index.md
+++ b/files/en-us/web/html/element/input/submit/index.md
@@ -52,7 +52,7 @@ A string that identifies the encoding method to use when submitting the form dat
 - `text/plain`
   - : Plain text; mostly useful only for debugging, so you can easily see the data that's to be submitted.
 
-If specified, the value of the `formenctype` attribute overrides the owning form's [`action`](/en-US/docs/Web/HTML/Element/form#action) attribute.
+If specified, the value of the `formenctype` attribute overrides the owning form's [`enctype`](/en-US/docs/Web/HTML/Element/form#enctype) attribute.
 
 This attribute is also available on [`<input type="image">`](/en-US/docs/Web/HTML/Element/input/image) and {{HTMLElement("button")}} elements.
 
diff --git a/files/en-us/web/html/element/input/time/index.md b/files/en-us/web/html/element/input/time/index.md
index 9a0669844bef623..8f37eabaa5dee24 100644
--- a/files/en-us/web/html/element/input/time/index.md
+++ b/files/en-us/web/html/element/input/time/index.md
@@ -284,7 +284,7 @@ In this example, we create an interface element for choosing time using the nati
 ### CSS
 
 ```css
-input[type="number"] {
+input[type="time"] {
   width: 100px;
 }
 
diff --git a/files/en-us/web/html/element/pre/index.md b/files/en-us/web/html/element/pre/index.md
index b707d9c8c363a65..edf71d114a288cf 100644
--- a/files/en-us/web/html/element/pre/index.md
+++ b/files/en-us/web/html/element/pre/index.md
@@ -7,7 +7,9 @@ browser-compat: html.elements.pre
 
 {{HTMLSidebar}}
 
-The **`<pre>`** [HTML](/en-US/docs/Web/HTML) element represents preformatted text which is to be presented exactly as written in the HTML file. The text is typically rendered using a non-proportional, or [monospaced](https://en.wikipedia.org/wiki/Monospaced_font), font. Whitespace inside this element is displayed as written.
+The **`<pre>`** [HTML](/en-US/docs/Web/HTML) element represents preformatted text which is to be presented exactly as written in the HTML file. The text is typically rendered using a non-proportional, or [monospaced](https://en.wikipedia.org/wiki/Monospaced_font) font.
+
+Whitespace inside this element is displayed as written, with one exception. If one or more leading newline characters are included immediately following the opening `<pre>` tag, the _first_ newline character is stripped.
 
 By default, `<pre>` is a [block-level](/en-US/docs/Glossary/Block-level_content) element, i.e. its default {{cssxref("display")}} value is `block`.
 
diff --git a/files/en-us/web/html/element/script/type/speculationrules/index.md b/files/en-us/web/html/element/script/type/speculationrules/index.md
index c4d111109b238b0..e25ec3d9b8e31fa 100644
--- a/files/en-us/web/html/element/script/type/speculationrules/index.md
+++ b/files/en-us/web/html/element/script/type/speculationrules/index.md
@@ -463,6 +463,9 @@ If a link is hovered over, the browser will start prefetching that specific link
 
 If the user hovers over another link before the prefetch completes, the `expects_no_vary_search` pattern tells the browser that there is no need to cancel the current prefetch, because all `/users` URLs with `id` URL parameter values effectively point to the same page for this context (and for caching purposes).
 
+> [!WARNING]
+> Additional care must be taken when using prerender with `No-Vary-Search` since the page may initially be prerendered with different URL parameters. `No-Vary-Search` is used for URL parameters that deliver the same resource from the server, but are used by the client for various reasons (client-side rendering, UTM parameters for analytics measurement, etc.). As the initial prerender may be for different URL parameters, any code depending on them should only run after prerender activation.
+
 ### `eagerness` example
 
 The following set of document rules shows how `eagerness` can be used to hint at the eagerness with which the browser should prerender each matching set of links.
diff --git a/files/en-us/web/html/element/time/index.md b/files/en-us/web/html/element/time/index.md
index abeb4cbc33f2cc2..9f94218d7a60727 100644
--- a/files/en-us/web/html/element/time/index.md
+++ b/files/en-us/web/html/element/time/index.md
@@ -74,7 +74,7 @@ The _datetime value_ (the machine-readable value of the datetime) is the value o
     <tr>
       <td>Valid local date and time string</td>
       <td>
-        <code><em>YYYY</em>-<em>MM</em>-<em>DD</em><em>HH</em>:<em>MM</em></code><br />
+        <code><em>YYYY</em>-<em>MM</em>-<em>DD</em> <em>HH</em>:<em>MM</em></code><br />
         <code><em>YYYY</em>-<em>MM</em>-<em>DD</em> <em>HH</em>:<em>MM</em>:<em>SS</em></code><br />
         <code><em>YYYY</em>-<em>MM</em>-<em>DD</em> <em>HH</em>:<em>MM</em>:<em>SS</em>.<em>mmm</em></code><br />
         <code><em>YYYY</em>-<em>MM</em>-<em>DD</em>T<em>HH</em>:<em>MM</em></code><br />
diff --git a/files/en-us/web/http/headers/content-security-policy/index.md b/files/en-us/web/http/headers/content-security-policy/index.md
index 2bfdd877f718cd9..3443265a5b127b2 100644
--- a/files/en-us/web/http/headers/content-security-policy/index.md
+++ b/files/en-us/web/http/headers/content-security-policy/index.md
@@ -1,5 +1,6 @@
 ---
-title: Content-Security-Policy
+title: Content-Security-Policy (CSP)
+short-title: Content-Security-Policy
 slug: Web/HTTP/Headers/Content-Security-Policy
 page-type: http-header
 browser-compat: http.headers.Content-Security-Policy
@@ -10,7 +11,7 @@ browser-compat: http.headers.Content-Security-Policy
 The HTTP **`Content-Security-Policy`** response header allows website administrators to control resources the user agent is allowed to load for a given page. With a few exceptions, policies mostly involve specifying server origins and script endpoints.
 This helps guard against {{Glossary("cross-site scripting")}} attacks.
 
-For more information, see the introductory article on [Content Security Policy (CSP)](/en-US/docs/Web/HTTP/CSP).
+See the [Content Security Policy (CSP)](/en-US/docs/Web/HTTP/CSP) guide for details about how a CSP is delivered to the browser, what it looks like, along with use cases and deployment strategies.
 
 <table class="properties">
   <tbody>
@@ -206,7 +207,8 @@ If a directive contains a nonce and `unsafe-inline`, then the browser ignores `u
 
 See [Nonces](/en-US/docs/Web/HTTP/CSP#nonces) in the CSP guide for more usage information.
 
-> [!NOTE] Nonce source expressions are only applicable to {{htmlelement("script")}} and {{htmlelement("style")}} elements.
+> [!NOTE]
+> Nonce source expressions are only applicable to {{htmlelement("script")}} and {{htmlelement("style")}} elements.
 
 ### '\<hash_algorithm>-<hash_value>'
 
@@ -229,7 +231,8 @@ If a directive contains a hash and `unsafe-inline`, then the browser ignores `un
 
 See [Hashes](/en-US/docs/Web/HTTP/CSP#hashes) in the CSP guide for more usage information.
 
-> [!NOTE] Hash source expressions are only applicable to {{htmlelement("script")}} and {{htmlelement("style")}} elements.
+> [!NOTE]
+> Hash source expressions are only applicable to {{htmlelement("script")}} and {{htmlelement("style")}} elements.
 
 ### \<host-source>
 
@@ -280,7 +283,8 @@ By default, if a CSP contains a `default-src` or a `script-src` directive, then
 
 The `unsafe-eval` keyword can be used to undo this protection, allowing dynamic evaluation of strings as JavaScript.
 
-> [!WARNING] Developers should avoid `'unsafe-eval'`, because it defeats much of the purpose of having a CSP.
+> [!WARNING]
+> Developers should avoid `'unsafe-eval'`, because it defeats much of the purpose of having a CSP.
 
 See [`eval()` and similar APIs](/en-US/docs/Web/HTTP/CSP#eval_and_similar_apis) in the CSP guide for more usage information.
 
@@ -305,7 +309,8 @@ Similarly, if a CSP contains `default-src` or a `style-src` directive, then inli
 
 The `unsafe-inline` keyword can be used to undo this protection, allowing all these forms to be loaded.
 
-> [!WARNING] Developers should avoid `'unsafe-inline'`, because it defeats much of the purpose of having a CSP.
+> [!WARNING]
+> Developers should avoid `'unsafe-inline'`, because it defeats much of the purpose of having a CSP.
 
 See [Inline JavaScript](/en-US/docs/Web/HTTP/CSP#inline_javascript) in the CSP guide for more usage information.
 
@@ -321,7 +326,8 @@ script-src 'unsafe-hashes' 'sha256-cd9827ad...'
 
 If the hash value matches the hash of an inline event handler attribute value or of a `style` attribute value, then the code will be allowed to execute.
 
-> [!WARNING] The `'unsafe-hashes'` value is unsafe.
+> [!WARNING]
+> The `'unsafe-hashes'` value is unsafe.
 >
 > In particular, it enables an attack in which the content of the inline event handler attribute is injected into the document as an inline `<script>` element. Suppose the inline event handler is:
 >
diff --git a/files/en-us/web/http/headers/content-security-policy/report-to/index.md b/files/en-us/web/http/headers/content-security-policy/report-to/index.md
index d536fabe5cba918..231b7c788974a68 100644
--- a/files/en-us/web/http/headers/content-security-policy/report-to/index.md
+++ b/files/en-us/web/http/headers/content-security-policy/report-to/index.md
@@ -73,7 +73,7 @@ The JSON for a single report might look like this:
 ## Usage notes
 
 The `report-to` directive is intended to replace `report-uri`, and browsers that support `report-to` ignore the `report-uri` directive.
-However, until `report-to` is broadly supported you can specify both headers as shown:
+However, until `report-to` is broadly supported you can specify both directives as shown:
 
 ```http
 Content-Security-Policy: …; report-uri https://endpoint.example.com; report-to endpoint_name
diff --git a/files/en-us/web/http/headers/no-vary-search/index.md b/files/en-us/web/http/headers/no-vary-search/index.md
index a2ab1fe58514c7b..44e2e1eccb2c407 100644
--- a/files/en-us/web/http/headers/no-vary-search/index.md
+++ b/files/en-us/web/http/headers/no-vary-search/index.md
@@ -5,7 +5,6 @@ page-type: http-header
 status:
   - experimental
 browser-compat: http.headers.No-Vary-Search
-spec-urls: https://wicg.github.io/nav-speculation/no-vary-search.html
 ---
 
 {{HTTPSidebar}}{{SeeCompatTable}}
@@ -13,9 +12,7 @@ spec-urls: https://wicg.github.io/nav-speculation/no-vary-search.html
 The HTTP **`No-Vary-Search`** {{Glossary("response header")}} specifies a set of rules that define how a URL's query parameters will affect cache matching.
 These rules dictate whether the same URL with different URL parameters should be saved as separate browser cache entries.
 
-> [!NOTE]
-> The [Speculation Rules API](/en-US/docs/Web/API/Speculation_Rules_API) can include an `expects_no_vary_search` field, which indicates to the browser what the expected `No-Vary-Search` value will be (if any) for documents that it is receiving prefetch/prerender requests for via the speculation rules.
-> The browser can use this to determine ahead of time whether it is more useful to wait for an existing prefetch/prerender to finish, or start a new fetch request when the speculation rule is matched.
+This allows the browser to reuse existing resources despite mismatching URL parameters to avoid the expense of fetching the resource again, when the same content will be returned.
 
 <table class="properties">
   <tbody>
@@ -57,6 +54,17 @@ No-Vary-Search: key-order, params, except=("param1")
     A boolean `params` directive has to be included for it to take effect (`params, except=("param1" "param2")`).
     The presence of other parameters that are not in the `except=` list _won't_ cause URLs to be cached as separate entries.
 
+## Description
+
+### Relationship with the Speculation Rules API
+
+The [Speculation Rules API](/en-US/docs/Web/API/Speculation_Rules_API) supports using the `No-Vary-Search` header to reuse an existing prefetched or prerendered page for different URL parameters — if they are included in the `No-Vary-Search` header.
+
+> [!WARNING]
+> Additional care must be taken when using prerender with `No-Vary-Search` since the page may initially be prerendered with different URL parameters. `No-Vary-Search` is used for URL parameters that deliver the same resource from the server, but are used by the client for various reasons (client-side rendering, UTM parameters for analytics measurement, etc.). As the initial prerender may be for different URL parameters, any code depending on them should only run after prerender activation.
+
+The Speculation Rules API can also include an `expects_no_vary_search` field, which indicates to the browser what the expected `No-Vary-Search` value will be (if any) for documents that it is receiving prefetch/prerender requests for via the speculation rules. The browser can use this to determine ahead of time whether it is more useful to wait for an existing prefetch/prerender to finish, or start a new fetch request when the speculation rule is matched. See the ["expects_no_vary_search" example](/en-US/docs/Web/HTML/Element/script/type/speculationrules#expects_no_vary_search_example) for an explanation of how this can be used.
+
 ## Examples
 
 ### Allowing responses from URLs with differently ordered params to match the same cache entry
@@ -109,6 +117,9 @@ You could get the browser to ignore all of these when considering cache matching
 No-Vary-Search: params=("id" "order" "lang")
 ```
 
+> [!NOTE]
+> As a [structured field](https://www.rfc-editor.org/rfc/rfc8941) the array of parameters should be space-separated quoted strings as shown above, and not comma-separated, which developers may be more used to.
+
 If you wanted the browser to ignore all of them _and_ any others that might be present when cache matching, you could use the boolean form of `params`:
 
 ```http
diff --git a/files/en-us/web/http/headers/x-frame-options/index.md b/files/en-us/web/http/headers/x-frame-options/index.md
index e3146f11bf1c43b..5e09c97a233aafd 100644
--- a/files/en-us/web/http/headers/x-frame-options/index.md
+++ b/files/en-us/web/http/headers/x-frame-options/index.md
@@ -2,15 +2,11 @@
 title: X-Frame-Options
 slug: Web/HTTP/Headers/X-Frame-Options
 page-type: http-header
-status:
-  - deprecated
 browser-compat: http.headers.X-Frame-Options
 ---
 
-{{HTTPSidebar}}{{deprecated_header}}
-
-> [!WARNING]
-> Instead of this header, use the {{HTTPHeader("Content-Security-Policy/frame-ancestors", "frame-ancestors")}} directive in a {{HTTPHeader("Content-Security-Policy")}} header.
+> [!NOTE]
+> For more comprehensive options than offered by this header, see the {{HTTPHeader("Content-Security-Policy/frame-ancestors", "frame-ancestors")}} directive in a {{HTTPHeader("Content-Security-Policy")}} header.
 
 The HTTP **`X-Frame-Options`** {{Glossary("response header")}} can be used to indicate whether a browser should be allowed to render a page in a {{HTMLElement("frame")}}, {{HTMLElement("iframe")}}, {{HTMLElement("embed")}} or {{HTMLElement("object")}}. Sites can use this to avoid [clickjacking](/en-US/docs/Web/Security/Types_of_attacks#clickjacking) attacks, by ensuring that their content is not embedded into other sites.
 
diff --git a/files/en-us/web/javascript/data_structures/index.md b/files/en-us/web/javascript/data_structures/index.md
index 266b7f8ad49cc62..14555fbee8c7da0 100644
--- a/files/en-us/web/javascript/data_structures/index.md
+++ b/files/en-us/web/javascript/data_structures/index.md
@@ -197,7 +197,7 @@ Objects are ad-hoc key-value pairs, so they are often used as maps. However, the
 
 ### Dates
 
-When representing dates, the best choice is to use the built-in [`Date`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date) utility in JavaScript.
+JavaScript provides two sets of APIs for representing dates: the legacy {{jsxref("Date")}} object and the modern {{jsxref("Temporal")}} object. `Date` has many undesirable design choices and should be avoided in new code if possible.
 
 ### Indexed collections: Arrays and typed Arrays
 
diff --git a/files/en-us/web/javascript/guide/expressions_and_operators/index.md b/files/en-us/web/javascript/guide/expressions_and_operators/index.md
index d30eaf61df658da..28436b950b8569c 100644
--- a/files/en-us/web/javascript/guide/expressions_and_operators/index.md
+++ b/files/en-us/web/javascript/guide/expressions_and_operators/index.md
@@ -4,7 +4,7 @@ slug: Web/JavaScript/Guide/Expressions_and_operators
 page-type: guide
 ---
 
-{{jsSidebar("JavaScript Guide")}} {{PreviousNext("Web/JavaScript/Guide/Functions", "Web/JavaScript/Guide/Numbers_and_dates")}}
+{{jsSidebar("JavaScript Guide")}} {{PreviousNext("Web/JavaScript/Guide/Functions", "Web/JavaScript/Guide/Numbers_and_strings")}}
 
 This chapter describes JavaScript's expressions and operators, including assignment, comparison, arithmetic, bitwise, logical, string, ternary and more.
 
@@ -1038,16 +1038,16 @@ if the specified object is of the specified object type. The syntax is:
 object instanceof objectType
 ```
 
-where `object` is the object to test against `objectType`, and `objectType` is a constructor representing a type, such as {{jsxref("Date")}} or {{jsxref("Array")}}.
+where `object` is the object to test against `objectType`, and `objectType` is a constructor representing a type, such as {{jsxref("Map")}} or {{jsxref("Array")}}.
 
 Use `instanceof` when you need to confirm the type of an object at runtime.
 For example, when catching exceptions, you can branch to different exception-handling code depending on the type of exception thrown.
 
-For example, the following code uses `instanceof` to determine whether `theDay` is a `Date` object. Because `theDay` is a `Date` object, the statements in the `if` statement execute.
+For example, the following code uses `instanceof` to determine whether `obj` is a `Map` object. Because `obj` is a `Map` object, the statements inside the `if` block execute.
 
 ```js
-const theDay = new Date(1995, 12, 17);
-if (theDay instanceof Date) {
+const obj = new Map();
+if (obj instanceof Map) {
   // statements to execute
 }
 ```
@@ -1148,4 +1148,4 @@ super(args); // calls the parent constructor.
 super.functionOnParent(args);
 ```
 
-{{PreviousNext("Web/JavaScript/Guide/Functions", "Web/JavaScript/Guide/Numbers_and_dates")}}
+{{PreviousNext("Web/JavaScript/Guide/Functions", "Web/JavaScript/Guide/Numbers_and_strings")}}
diff --git a/files/en-us/web/javascript/guide/index.md b/files/en-us/web/javascript/guide/index.md
index 519ddda2756fb4f..42bb63e60f2f8f8 100644
--- a/files/en-us/web/javascript/guide/index.md
+++ b/files/en-us/web/javascript/guide/index.md
@@ -73,24 +73,33 @@ Overview: [Expressions and operators](/en-US/docs/Web/JavaScript/Guide/Expressio
 - [Bitwise](/en-US/docs/Web/JavaScript/Guide/Expressions_and_operators#bitwise_operators) & [logical operators](/en-US/docs/Web/JavaScript/Guide/Expressions_and_operators#logical_operators)
 - [Conditional (ternary) operator](</en-US/docs/Web/JavaScript/Guide/Expressions_and_operators#conditional_(ternary)_operator>)
 
-## Numbers and dates
+## Numbers and strings
 
-Overview: [Numbers and dates](/en-US/docs/Web/JavaScript/Guide/Numbers_and_dates)
+Overview: [Numbers and strings](/en-US/docs/Web/JavaScript/Guide/Numbers_and_strings)
 
-- [Number literals](/en-US/docs/Web/JavaScript/Guide/Numbers_and_dates#numbers)
-- [`Number` object](/en-US/docs/Web/JavaScript/Guide/Numbers_and_dates#number_object)
-- [`Math` object](/en-US/docs/Web/JavaScript/Guide/Numbers_and_dates#math_object)
-- [`Date` object](/en-US/docs/Web/JavaScript/Guide/Numbers_and_dates#date_object)
+- [Numbers](/en-US/docs/Web/JavaScript/Guide/Numbers_and_strings#numbers)
+- [`Number` object](/en-US/docs/Web/JavaScript/Guide/Numbers_and_strings#number_object)
+- [`Math` object](/en-US/docs/Web/JavaScript/Guide/Numbers_and_strings#math_object)
+- [Strings](/en-US/docs/Web/JavaScript/Guide/Numbers_and_strings#strings)
+- [`String` object](/en-US/docs/Web/JavaScript/Guide/Numbers_and_strings#string_object)
+- [Template literals](/en-US/docs/Web/JavaScript/Guide/Numbers_and_strings#template_literals)
 
-## Text formatting
+## Representing dates & times
 
-Overview: [Text formatting](/en-US/docs/Web/JavaScript/Guide/Text_formatting)
+Overview: [Representing dates & times](/en-US/docs/Web/JavaScript/Guide/Representing_dates_times)
 
-- [String literals](/en-US/docs/Web/JavaScript/Guide/Text_formatting#string_literals)
-- [`String` object](/en-US/docs/Web/JavaScript/Guide/Text_formatting#string_objects)
-- [Template literals](/en-US/docs/Web/JavaScript/Guide/Text_formatting#multi-line_template_literals)
-- [Internationalization](/en-US/docs/Web/JavaScript/Guide/Text_formatting#internationalization)
-- [Regular Expressions](/en-US/docs/Web/JavaScript/Guide/Regular_expressions)
+- [`Date` object](/en-US/docs/Web/JavaScript/Guide/Representing_dates_times#date_object)
+
+## Regular expressions
+
+Overview: [Regular expressions](/en-US/docs/Web/JavaScript/Guide/Regular_expressions)
+
+- [Creating a regular expression](/en-US/docs/Web/JavaScript/Guide/Regular_expressions#creating_a_regular_expression)
+- [Writing a regular expression pattern](/en-US/docs/Web/JavaScript/Guide/Regular_expressions#writing_a_regular_expression_pattern)
+  - [Assertions](/en-US/docs/Web/JavaScript/Guide/Regular_expressions/Assertions)
+  - [Character classes](/en-US/docs/Web/JavaScript/Guide/Regular_expressions/Character_classes)
+  - [Groups and backreferences](/en-US/docs/Web/JavaScript/Guide/Regular_expressions/Groups_and_backreferences)
+  - [Quantifiers](/en-US/docs/Web/JavaScript/Guide/Regular_expressions/Quantifiers)
 
 ## Indexed collections
 
@@ -145,6 +154,14 @@ Overview: [Iterators and generators](/en-US/docs/Web/JavaScript/Guide/Iterators_
 - [Iterables](/en-US/docs/Web/JavaScript/Guide/Iterators_and_generators#iterables)
 - [Generators](/en-US/docs/Web/JavaScript/Guide/Iterators_and_generators#generator_functions)
 
+## Internationalization
+
+Overview: [Internationalization](/en-US/docs/Web/JavaScript/Guide/Internationalization)
+
+- [Date and time formatting](/en-US/docs/Web/JavaScript/Guide/Internationalization#date_and_time_formatting)
+- [Number formatting](/en-US/docs/Web/JavaScript/Guide/Internationalization#number_formatting)
+- [Collation](/en-US/docs/Web/JavaScript/Guide/Internationalization#collation)
+
 ## Meta programming
 
 Overview: [Meta programming](/en-US/docs/Web/JavaScript/Guide/Meta_programming)
diff --git a/files/en-us/web/javascript/guide/internationalization/index.md b/files/en-us/web/javascript/guide/internationalization/index.md
new file mode 100644
index 000000000000000..ebf923b3902742f
--- /dev/null
+++ b/files/en-us/web/javascript/guide/internationalization/index.md
@@ -0,0 +1,84 @@
+---
+title: Internationalization
+slug: Web/JavaScript/Guide/Internationalization
+page-type: guide
+---
+
+{{jsSidebar("JavaScript Guide")}} {{PreviousNext("Web/JavaScript/Guide/Iterators_and_generators", "Web/JavaScript/Guide/Meta_programming")}}
+
+The {{jsxref("Intl")}} object is the namespace for the ECMAScript Internationalization API, which provides a wide range of locale- and culture-sensitive data and operations.
+
+## Date and time formatting
+
+The {{jsxref("Intl.DateTimeFormat")}} object is useful for formatting date and time. The following formats a date for English as used in the United States. (The result is different in another time zone.)
+
+```js
+// July 17, 2014 00:00:00 UTC:
+const july172014 = new Date("2014-07-17");
+
+const options = {
+  year: "2-digit",
+  month: "2-digit",
+  day: "2-digit",
+  hour: "2-digit",
+  minute: "2-digit",
+  timeZoneName: "short",
+};
+const americanDateTime = new Intl.DateTimeFormat("en-US", options).format;
+
+// Local timezone vary depending on your settings
+// In CEST, logs: 07/17/14, 02:00 AM GMT+2
+// In PDT, logs: 07/16/14, 05:00 PM GMT-7
+console.log(americanDateTime(july172014));
+```
+
+## Number formatting
+
+The {{jsxref("Intl.NumberFormat")}} object is useful for formatting numbers, for example currencies.
+
+```js
+const gasPrice = new Intl.NumberFormat("en-US", {
+  style: "currency",
+  currency: "USD",
+  minimumFractionDigits: 3,
+});
+
+console.log(gasPrice.format(5.259)); // $5.259
+
+const hanDecimalRMBInChina = new Intl.NumberFormat("zh-CN-u-nu-hanidec", {
+  style: "currency",
+  currency: "CNY",
+});
+
+console.log(hanDecimalRMBInChina.format(1314.25)); // ￥ 一,三一四.二五
+```
+
+## Collation
+
+The {{jsxref("Intl.Collator")}} object is useful for comparing and sorting strings.
+
+For example, there are actually two different sort orders in German, _phonebook_ and _dictionary_. Phonebook sort emphasizes sound, and it's as if "ä", "ö", and so on were expanded to "ae", "oe", and so on prior to sorting.
+
+```js
+const names = ["Hochberg", "Hönigswald", "Holzman"];
+
+const germanPhonebook = new Intl.Collator("de-DE-u-co-phonebk");
+
+// as if sorting ["Hochberg", "Hoenigswald", "Holzman"]:
+console.log(names.sort(germanPhonebook.compare).join(", "));
+// "Hochberg, Hönigswald, Holzman"
+```
+
+Some German words conjugate with extra umlauts, so in dictionaries it's sensible to order ignoring umlauts (except when ordering words differing _only_ by umlauts: _schon_ before _schön_).
+
+```js
+const germanDictionary = new Intl.Collator("de-DE-u-co-dict");
+
+// as if sorting ["Hochberg", "Honigswald", "Holzman"]:
+console.log(names.sort(germanDictionary.compare).join(", "));
+// "Hochberg, Holzman, Hönigswald"
+```
+
+For more information about the {{jsxref("Intl")}} API, see also [Introducing the JavaScript Internationalization API](https://hacks.mozilla.org/2014/12/introducing-the-javascript-internationalization-api/).
+
+{{PreviousNext("Web/JavaScript/Guide/Iterators_and_generators", "Web/JavaScript/Guide/Meta_programming")}}
diff --git a/files/en-us/web/javascript/guide/introduction/index.md b/files/en-us/web/javascript/guide/introduction/index.md
index 03774af06de7e99..78ada46ed2e8454 100644
--- a/files/en-us/web/javascript/guide/introduction/index.md
+++ b/files/en-us/web/javascript/guide/introduction/index.md
@@ -28,7 +28,7 @@ The JavaScript documentation on MDN includes the following:
 
 JavaScript is a cross-platform, object-oriented scripting language used to make webpages interactive (e.g., having complex animations, clickable buttons, popup menus, etc.). There are also more advanced server side versions of JavaScript such as Node.js, which allow you to add more functionality to a website than downloading files (such as realtime collaboration between multiple computers). Inside a host environment (for example, a web browser), JavaScript can be connected to the objects of its environment to provide programmatic control over them.
 
-JavaScript contains a standard library of objects, such as `Array`, `Date`, and `Math`, and a core set of language elements such as operators, control structures, and statements. Core JavaScript can be extended for a variety of purposes by supplementing it with additional objects; for example:
+JavaScript contains a standard library of objects, such as `Array`, `Map`, and `Math`, and a core set of language elements such as operators, control structures, and statements. Core JavaScript can be extended for a variety of purposes by supplementing it with additional objects; for example:
 
 - _Client-side JavaScript_ extends the core language by supplying objects to control a browser and its _Document Object Model_ (DOM). For example, client-side extensions allow an application to place elements on an HTML form and respond to user events such as mouse clicks, form input, and page navigation.
 - _Server-side JavaScript_ extends the core language by supplying objects relevant to running JavaScript on a server. For example, server-side extensions allow an application to communicate with a database, provide continuity of information from one invocation to another of the application, or perform file manipulations on a server.
diff --git a/files/en-us/web/javascript/guide/iterators_and_generators/index.md b/files/en-us/web/javascript/guide/iterators_and_generators/index.md
index 8753c53ab4755e2..cff573845cd0145 100644
--- a/files/en-us/web/javascript/guide/iterators_and_generators/index.md
+++ b/files/en-us/web/javascript/guide/iterators_and_generators/index.md
@@ -4,7 +4,7 @@ slug: Web/JavaScript/Guide/Iterators_and_generators
 page-type: guide
 ---
 
-{{jsSidebar("JavaScript Guide")}} {{PreviousNext("Web/JavaScript/Guide/Typed_arrays", "Web/JavaScript/Guide/Meta_programming")}}
+{{jsSidebar("JavaScript Guide")}} {{PreviousNext("Web/JavaScript/Guide/Typed_arrays", "Web/JavaScript/Guide/Internationalization")}}
 
 Iterators and Generators bring the concept of iteration directly into the core language and provide a mechanism for customizing the behavior of {{jsxref("Statements/for...of", "for...of")}} loops.
 
@@ -234,4 +234,4 @@ If the exception is not caught from within the generator, it will propagate up t
 
 Generators have a {{jsxref("Generator/return", "return()")}} method that returns the given value and finishes the generator itself.
 
-{{PreviousNext("Web/JavaScript/Guide/Typed_arrays", "Web/JavaScript/Guide/Meta_programming")}}
+{{PreviousNext("Web/JavaScript/Guide/Typed_arrays", "Web/JavaScript/Guide/Internationalization")}}
diff --git a/files/en-us/web/javascript/guide/meta_programming/index.md b/files/en-us/web/javascript/guide/meta_programming/index.md
index 57e311e4a0851cf..3ded1b7f589eec1 100644
--- a/files/en-us/web/javascript/guide/meta_programming/index.md
+++ b/files/en-us/web/javascript/guide/meta_programming/index.md
@@ -4,7 +4,7 @@ slug: Web/JavaScript/Guide/Meta_programming
 page-type: guide
 ---
 
-{{jsSidebar("JavaScript Guide")}}{{PreviousNext("Web/JavaScript/Guide/Iterators_and_generators", "Web/JavaScript/Guide/Modules")}}
+{{jsSidebar("JavaScript Guide")}}{{PreviousNext("Web/JavaScript/Guide/Internationalization", "Web/JavaScript/Guide/Modules")}}
 
 The {{jsxref("Proxy")}} and {{jsxref("Reflect")}} objects allow you to intercept and define custom behavior for fundamental language operations (e.g. property lookup, assignment, enumeration, function invocation, etc.). With the help of these two objects you are able to program at the meta level of JavaScript.
 
@@ -282,4 +282,4 @@ if (Reflect.defineProperty(target, property, attributes)) {
 }
 ```
 
-{{PreviousNext("Web/JavaScript/Guide/Iterators_and_generators", "Web/JavaScript/Guide/Modules")}}
+{{PreviousNext("Web/JavaScript/Guide/Internationalization", "Web/JavaScript/Guide/Modules")}}
diff --git a/files/en-us/web/javascript/guide/numbers_and_dates/index.md b/files/en-us/web/javascript/guide/numbers_and_strings/index.md
similarity index 70%
rename from files/en-us/web/javascript/guide/numbers_and_dates/index.md
rename to files/en-us/web/javascript/guide/numbers_and_strings/index.md
index f3e63d33f23f483..c54bb98603eb34a 100644
--- a/files/en-us/web/javascript/guide/numbers_and_dates/index.md
+++ b/files/en-us/web/javascript/guide/numbers_and_strings/index.md
@@ -1,12 +1,12 @@
 ---
-title: Numbers and dates
-slug: Web/JavaScript/Guide/Numbers_and_dates
+title: Numbers and strings
+slug: Web/JavaScript/Guide/Numbers_and_strings
 page-type: guide
 ---
 
-{{jsSidebar("JavaScript Guide")}} {{PreviousNext("Web/JavaScript/Guide/Expressions_and_operators", "Web/JavaScript/Guide/Text_formatting")}}
+{{jsSidebar("JavaScript Guide")}} {{PreviousNext("Web/JavaScript/Guide/Expressions_and_operators", "Web/JavaScript/Guide/Representing_dates_times")}}
 
-This chapter introduces the concepts, objects and functions used to work with and perform calculations using numbers and dates in JavaScript. This includes using numbers written in various bases including decimal, binary, and hexadecimal, as well as the use of the global {{jsxref("Math")}} object to perform a wide variety of mathematical operations on numbers.
+This chapter introduces the two most fundamental data types in JavaScript: numbers and strings. We will introduce their underlying representations, and functions used to work with and perform calculations on them.
 
 ## Numbers
 
@@ -310,106 +310,120 @@ Choosing between BigInt and number depends on your use-case and your input's ran
 
 Read more about what you can do with BigInt values in the [Expressions and Operators](/en-US/docs/Web/JavaScript/Guide/Expressions_and_operators#bigint_operators) section, or the [BigInt reference](/en-US/docs/Web/JavaScript/Reference/Global_Objects/BigInt).
 
-## Date object
+## Strings
 
-JavaScript does not have a date data type. However, you can use the {{jsxref("Date")}} object and its methods to work with dates and times in your applications. The `Date` object has a large number of methods for setting, getting, and manipulating dates. It does not have any properties.
+JavaScript's [String](/en-US/docs/Glossary/String) type is used to represent textual data. It is a set of "elements" of 16-bit unsigned integer values (UTF-16 code units). Each element in the String occupies a position in the String. The first element is at index 0, the next at index 1, and so on. The length of a String is the number of elements in it. You can create strings using string literals or string objects.
 
-JavaScript handles dates similarly to Java. The two languages have many of the same date methods, and both languages store dates as the number of milliseconds since midnight at the beginning of January 1, 1970, UTC, with a Unix Timestamp being the number of seconds since the same instant. The instant at the midnight at the beginning of January 1, 1970, UTC is called the [epoch](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date#the_epoch_timestamps_and_invalid_date).
+### String literals
 
-The `Date` object range is -100,000,000 days to 100,000,000 days relative to the epoch.
+You can declare strings in source code using either single or double quotes:
 
-To create a `Date` object:
+```js-nolint
+'foo'
+"bar"
+```
 
-```js
-const dateObjectName = new Date([parameters]);
+Within a string literal, most characters can be entered literally. The only exceptions are the backslash (`\`, which starts an escape sequence), the quote character being used to enclose the string, which terminates the string, and the newline character, which is a syntax error if not preceded by a backslash.
+
+More advanced strings can be created using escape sequences:
+
+#### Hexadecimal escape sequences
+
+The number after \x is interpreted as a [hexadecimal](https://en.wikipedia.org/wiki/Hexadecimal) number.
+
+```js-nolint
+"\xA9" // "©"
 ```
 
-where `dateObjectName` is the name of the `Date` object being created; it can be a new object or a property of an existing object.
+#### Unicode escape sequences
 
-Calling `Date` without the `new` keyword returns a string representing the current date and time.
+The Unicode escape sequences require at least four hexadecimal digits following `\u`.
 
-The `parameters` in the preceding syntax can be any of the following:
+```js-nolint
+"\u00A9" // "©"
+```
 
-- Nothing: creates today's date and time. For example, `today = new Date();`.
-- A string representing a date, in many different forms. The exact forms supported differ among engines, but the following form is always supported: `YYYY-MM-DDTHH:mm:ss.sssZ`. For example, `xmas95 = new Date("1995-12-25")`. If you omit hours, minutes, or seconds, the value will be set to zero.
-- A set of integer values for year, month, and day. For example, `xmas95 = new Date(1995, 11, 25)`.
-- A set of integer values for year, month, day, hour, minute, and seconds. For example, `xmas95 = new Date(1995, 11, 25, 9, 30, 0);`.
+#### Unicode code point escapes
 
-### Methods of the Date object
+With Unicode code point escapes, any character can be escaped using hexadecimal numbers so that it is possible to use Unicode code points up to `0x10FFFF`. With the four-digit Unicode escapes it is often necessary to write the surrogate halves separately to achieve the same result.
 
-The `Date` object methods for handling dates and times fall into these broad categories:
+See also {{jsxref("String.fromCodePoint()")}} or {{jsxref("String.prototype.codePointAt()")}}.
 
-- "set" methods, for setting date and time values in `Date` objects.
-- "get" methods, for getting date and time values from `Date` objects.
-- "to" methods, for returning string values from `Date` objects.
-- parse and UTC methods, for parsing `Date` strings.
+```js-nolint
+"\u{2F804}"
 
-With the "get" and "set" methods you can get and set seconds, minutes, hours, day of the month, day of the week, months, and years separately. There is a `getDay` method that returns the day of the week, but no corresponding `setDay` method, because the day of the week is set automatically. These methods use integers to represent these values as follows:
+// the same with simple Unicode escapes
+"\uD87E\uDC04"
+```
 
-- Seconds and minutes: 0 to 59
-- Hours: 0 to 23
-- Day: 0 (Sunday) to 6 (Saturday)
-- Date: 1 to 31 (day of the month)
-- Months: 0 (January) to 11 (December)
-- Year: years since 1900
+## String object
 
-For example, suppose you define the following date:
+You can call methods directly on a string value:
 
 ```js
-const xmas95 = new Date("1995-12-25");
+console.log("hello".toUpperCase()); // HELLO
 ```
 
-Then `xmas95.getMonth()` returns 11, and `xmas95.getFullYear()` returns 1995.
+The following methods are available on {{jsxref("String")}} values:
+
+- Query: get the character or character code at a particular string index. Methods include {{jsxref("String/at", "at()")}}, {{jsxref("String/charAt", "charAt()")}}, {{jsxref("String/charCodeAt", "charCodeAt()")}}, and {{jsxref("String/codePointAt", "codePointAt()")}}.
+- Search: get information about a substring that conforms to a pattern, or test if a particular substring exists. Methods include {{jsxref("String/indexOf", "indexOf()")}}, {{jsxref("String/lastIndexOf", "lastIndexOf()")}}, {{jsxref("String/startsWith", "startsWith()")}}, {{jsxref("String/endsWith", "endsWith()")}}, {{jsxref("String/includes", "includes()")}}, {{jsxref("String/match", "match()")}}, {{jsxref("String/matchAll", "matchAll()")}}, and {{jsxref("String/search", "search()")}}
+- Composition: combine strings into a longer string. Methods include {{jsxref("String/padStart", "padStart()")}}, {{jsxref("String/padEnd", "padEnd()")}}, {{jsxref("String/concat", "concat()")}}, and {{jsxref("String/repeat", "repeat()")}}.
+- Decomposition: break a string into smaller strings. Methods include {{jsxref("String/split", "split()")}}, {{jsxref("String/slice", "slice()")}}, {{jsxref("String/substring", "substring()")}}, {{jsxref("String/substr", "substr()")}}, {{jsxref("String/trim", "trim()")}}, {{jsxref("String/trimStart", "trimStart()")}}, and {{jsxref("String/trimEnd", "trimEnd()")}}.
+- Transformation: return a new string based on the current string's content. Methods include {{jsxref("String/toLowerCase", "toLowerCase()")}}, {{jsxref("String/toUpperCase", "toUpperCase()")}}, {{jsxref("String/toLocaleLowerCase", "toLocaleLowerCase()")}}, {{jsxref("String/toLocaleUpperCase", "toLocaleUpperCase()")}}, {{jsxref("String/normalize", "normalize()")}}, and {{jsxref("String/toWellFormed", "toWellFormed()")}}.
+
+When working with strings, there are two other objects that provide important functionality for string manipulation: {{jsxref("RegExp")}} and {{jsxref("Intl")}}. They are introduced in [regular expressions](/en-US/docs/Web/JavaScript/Guide/Regular_expressions) and [internationalization](/en-US/docs/Web/JavaScript/Guide/Internationalization) respectively.
+
+## Template literals
+
+[Template literals](/en-US/docs/Web/JavaScript/Reference/Template_literals) are string literals allowing embedded expressions. You can use multi-line strings and string interpolation features with them.
 
-The `getTime` and `setTime` methods are useful for comparing dates. The `getTime` method returns the number of milliseconds since the epoch for a `Date` object.
+Template literals are enclosed by backtick ([grave accent](https://en.wikipedia.org/wiki/Grave_accent)) characters (`` ` ``) instead of double or single quotes. Template literals can contain placeholders. These are indicated by the dollar sign and curly braces (`${expression}`).
 
-For example, the following code displays the number of days left in the current year:
+### Multi-lines
+
+Any new line characters inserted in the source are part of the template literal. Using normal strings, you would have to use the following syntax in order to get multi-line strings:
 
 ```js
-const today = new Date();
-const endYear = new Date(1995, 11, 31, 23, 59, 59, 999); // Set day and month
-endYear.setFullYear(today.getFullYear()); // Set year to this year
-const msPerDay = 24 * 60 * 60 * 1000; // Number of milliseconds per day
-let daysLeft = (endYear.getTime() - today.getTime()) / msPerDay;
-daysLeft = Math.round(daysLeft); // Returns days left in the year
+console.log(
+  "string text line 1\n\
+string text line 2",
+);
+// "string text line 1
+// string text line 2"
 ```
 
-This example creates a `Date` object named `today` that contains today's date. It then creates a `Date` object named `endYear` and sets the year to the current year. Then, using the number of milliseconds per day, it computes the number of days between `today` and `endYear`, using `getTime` and rounding to a whole number of days.
-
-The `parse` method is useful for assigning values from date strings to existing `Date` objects. For example, the following code uses `parse` and `setTime` to assign a date value to the `ipoDate` object:
+To get the same effect with multi-line strings, you can now write:
 
 ```js
-const ipoDate = new Date();
-ipoDate.setTime(Date.parse("Aug 9, 1995"));
+console.log(`string text line 1
+string text line 2`);
+// "string text line 1
+// string text line 2"
 ```
 
-### Example
+### Embedded expressions
 
-In the following example, the function `JSClock()` returns the time in the format of a digital clock.
+In order to embed expressions within normal strings, you would use the following syntax:
 
 ```js
-function JSClock() {
-  const time = new Date();
-  const hour = time.getHours();
-  const minute = time.getMinutes();
-  const second = time.getSeconds();
-  let temp = String(hour % 12);
-  if (temp === "0") {
-    temp = "12";
-  }
-  temp += (minute < 10 ? ":0" : ":") + minute;
-  temp += (second < 10 ? ":0" : ":") + second;
-  temp += hour >= 12 ? " P.M." : " A.M.";
-  return temp;
-}
+const five = 5;
+const ten = 10;
+console.log(
+  "Fifteen is " + (five + ten) + " and not " + (2 * five + ten) + ".",
+);
+// "Fifteen is 15 and not 20."
 ```
 
-The `JSClock` function first creates a new `Date` object called `time`; since no arguments are given, time is created with the current date and time. Then calls to the `getHours`, `getMinutes`, and `getSeconds` methods assign the value of the current hour, minute, and second to `hour`, `minute`, and `second`.
-
-The following statements build a string value based on the time. The first statement creates a variable `temp`. Its value is `hour % 12`, which is `hour` in the 12-hour system. Then, if the hour is `0`, it gets re-assigned to `12`, so that midnights and noons are displayed as `12:00` instead of `0:00`.
+Now, with template literals, you are able to make use of the syntactic sugar making substitutions like this more readable:
 
-The next statement appends a `minute` value to `temp`. If the value of `minute` is less than 10, the conditional expression adds a string with a preceding zero; otherwise it adds a string with a demarcating colon. Then a statement appends a seconds value to `temp` in the same way.
+```js
+const five = 5;
+const ten = 10;
+console.log(`Fifteen is ${five + ten} and not ${2 * five + ten}.`);
+// "Fifteen is 15 and not 20."
+```
 
-Finally, a conditional expression appends "P.M." to `temp` if `hour` is 12 or greater; otherwise, it appends "A.M." to `temp`.
+For more information, read about [Template literals](/en-US/docs/Web/JavaScript/Reference/Template_literals) in the [JavaScript reference](/en-US/docs/Web/JavaScript/Reference).
 
-{{PreviousNext("Web/JavaScript/Guide/Expressions_and_operators", "Web/JavaScript/Guide/Text_formatting")}}
+{{PreviousNext("Web/JavaScript/Guide/Expressions_and_operators", "Web/JavaScript/Guide/Representing_dates_times")}}
diff --git a/files/en-us/web/javascript/guide/regular_expressions/index.md b/files/en-us/web/javascript/guide/regular_expressions/index.md
index 07ab0d0913ab478..b49f40514e82984 100644
--- a/files/en-us/web/javascript/guide/regular_expressions/index.md
+++ b/files/en-us/web/javascript/guide/regular_expressions/index.md
@@ -4,7 +4,7 @@ slug: Web/JavaScript/Guide/Regular_expressions
 page-type: guide
 ---
 
-{{jsSidebar("JavaScript Guide")}} {{PreviousNext("Web/JavaScript/Guide/Text_formatting", "Web/JavaScript/Guide/Indexed_collections")}}
+{{jsSidebar("JavaScript Guide")}} {{PreviousNext("Web/JavaScript/Guide/Representing_dates_times", "Web/JavaScript/Guide/Indexed_collections")}}
 
 Regular expressions are patterns used to match character combinations in strings.
 In JavaScript, regular expressions are also objects. These patterns are used with the {{jsxref("RegExp/exec", "exec()")}} and {{jsxref("RegExp/test", "test()")}} methods of {{jsxref("RegExp")}}, and with the {{jsxref("String/match", "match()")}}, {{jsxref("String/matchAll", "matchAll()")}}, {{jsxref("String/replace", "replace()")}}, {{jsxref("String/replaceAll", "replaceAll()")}}, {{jsxref("String/search", "search()")}}, and {{jsxref("String/split", "split()")}} methods of {{jsxref("String")}}.
@@ -456,4 +456,4 @@ form.addEventListener("submit", (event) => {
 - [Regex visualizer](https://extendsclass.com/regex-tester.html)
   - : An online visual regex tester.
 
-{{PreviousNext("Web/JavaScript/Guide/Text_formatting", "Web/JavaScript/Guide/Indexed_collections")}}
+{{PreviousNext("Web/JavaScript/Guide/Representing_dates_times", "Web/JavaScript/Guide/Indexed_collections")}}
diff --git a/files/en-us/web/javascript/guide/representing_dates_times/index.md b/files/en-us/web/javascript/guide/representing_dates_times/index.md
new file mode 100644
index 000000000000000..ee14cc0053a3286
--- /dev/null
+++ b/files/en-us/web/javascript/guide/representing_dates_times/index.md
@@ -0,0 +1,114 @@
+---
+title: Representing dates & times
+slug: Web/JavaScript/Guide/Representing_dates_times
+page-type: guide
+---
+
+{{jsSidebar("JavaScript Guide")}} {{PreviousNext("Web/JavaScript/Guide/Numbers_and_strings", "Web/JavaScript/Guide/Regular_expressions")}}
+
+> [!NOTE]
+> The `Date` object is now considered legacy and should be avoided in new code. We will update this page with modern alternatives soon.
+
+## Date object
+
+JavaScript does not have a date data type. However, you can use the {{jsxref("Date")}} object and its methods to work with dates and times in your applications. The `Date` object has a large number of methods for setting, getting, and manipulating dates. It does not have any properties.
+
+JavaScript handles dates similarly to Java. The two languages have many of the same date methods, and both languages store dates as the number of milliseconds since midnight at the beginning of January 1, 1970, UTC, with a Unix Timestamp being the number of seconds since the same instant. The instant at the midnight at the beginning of January 1, 1970, UTC is called the [epoch](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date#the_epoch_timestamps_and_invalid_date).
+
+The `Date` object range is -100,000,000 days to 100,000,000 days relative to the epoch.
+
+To create a `Date` object:
+
+```js
+const dateObjectName = new Date([parameters]);
+```
+
+where `dateObjectName` is the name of the `Date` object being created; it can be a new object or a property of an existing object.
+
+Calling `Date` without the `new` keyword returns a string representing the current date and time.
+
+The `parameters` in the preceding syntax can be any of the following:
+
+- Nothing: creates today's date and time. For example, `today = new Date();`.
+- A string representing a date, in many different forms. The exact forms supported differ among engines, but the following form is always supported: `YYYY-MM-DDTHH:mm:ss.sssZ`. For example, `xmas95 = new Date("1995-12-25")`. If you omit hours, minutes, or seconds, the value will be set to zero.
+- A set of integer values for year, month, and day. For example, `xmas95 = new Date(1995, 11, 25)`.
+- A set of integer values for year, month, day, hour, minute, and seconds. For example, `xmas95 = new Date(1995, 11, 25, 9, 30, 0);`.
+
+### Methods of the Date object
+
+The `Date` object methods for handling dates and times fall into these broad categories:
+
+- "set" methods, for setting date and time values in `Date` objects.
+- "get" methods, for getting date and time values from `Date` objects.
+- "to" methods, for returning string values from `Date` objects.
+- parse and UTC methods, for parsing `Date` strings.
+
+With the "get" and "set" methods you can get and set seconds, minutes, hours, day of the month, day of the week, months, and years separately. There is a `getDay` method that returns the day of the week, but no corresponding `setDay` method, because the day of the week is set automatically. These methods use integers to represent these values as follows:
+
+- Seconds and minutes: 0 to 59
+- Hours: 0 to 23
+- Day: 0 (Sunday) to 6 (Saturday)
+- Date: 1 to 31 (day of the month)
+- Months: 0 (January) to 11 (December)
+- Year: years since 1900
+
+For example, suppose you define the following date:
+
+```js
+const xmas95 = new Date("1995-12-25");
+```
+
+Then `xmas95.getMonth()` returns 11, and `xmas95.getFullYear()` returns 1995.
+
+The `getTime` and `setTime` methods are useful for comparing dates. The `getTime` method returns the number of milliseconds since the epoch for a `Date` object.
+
+For example, the following code displays the number of days left in the current year:
+
+```js
+const today = new Date();
+const endYear = new Date(1995, 11, 31, 23, 59, 59, 999); // Set day and month
+endYear.setFullYear(today.getFullYear()); // Set year to this year
+const msPerDay = 24 * 60 * 60 * 1000; // Number of milliseconds per day
+let daysLeft = (endYear.getTime() - today.getTime()) / msPerDay;
+daysLeft = Math.round(daysLeft); // Returns days left in the year
+```
+
+This example creates a `Date` object named `today` that contains today's date. It then creates a `Date` object named `endYear` and sets the year to the current year. Then, using the number of milliseconds per day, it computes the number of days between `today` and `endYear`, using `getTime` and rounding to a whole number of days.
+
+The `parse` method is useful for assigning values from date strings to existing `Date` objects. For example, the following code uses `parse` and `setTime` to assign a date value to the `ipoDate` object:
+
+```js
+const ipoDate = new Date();
+ipoDate.setTime(Date.parse("Aug 9, 1995"));
+```
+
+### Example
+
+In the following example, the function `JSClock()` returns the time in the format of a digital clock.
+
+```js
+function JSClock() {
+  const time = new Date();
+  const hour = time.getHours();
+  const minute = time.getMinutes();
+  const second = time.getSeconds();
+  let temp = String(hour % 12);
+  if (temp === "0") {
+    temp = "12";
+  }
+  temp += (minute < 10 ? ":0" : ":") + minute;
+  temp += (second < 10 ? ":0" : ":") + second;
+  temp += hour >= 12 ? " P.M." : " A.M.";
+  return temp;
+}
+```
+
+The `JSClock` function first creates a new `Date` object called `time`; since no arguments are given, time is created with the current date and time. Then calls to the `getHours`, `getMinutes`, and `getSeconds` methods assign the value of the current hour, minute, and second to `hour`, `minute`, and `second`.
+
+The following statements build a string value based on the time. The first statement creates a variable `temp`. Its value is `hour % 12`, which is `hour` in the 12-hour system. Then, if the hour is `0`, it gets re-assigned to `12`, so that midnights and noons are displayed as `12:00` instead of `0:00`.
+
+The next statement appends a `minute` value to `temp`. If the value of `minute` is less than 10, the conditional expression adds a string with a preceding zero; otherwise it adds a string with a demarcating colon. Then a statement appends a seconds value to `temp` in the same way.
+
+Finally, a conditional expression appends "P.M." to `temp` if `hour` is 12 or greater; otherwise, it appends "A.M." to `temp`.
+
+{{PreviousNext("Web/JavaScript/Guide/Numbers_and_strings", "Web/JavaScript/Guide/Regular_expressions")}}
diff --git a/files/en-us/web/javascript/guide/text_formatting/index.md b/files/en-us/web/javascript/guide/text_formatting/index.md
deleted file mode 100644
index 18a0fb312ee54f0..000000000000000
--- a/files/en-us/web/javascript/guide/text_formatting/index.md
+++ /dev/null
@@ -1,326 +0,0 @@
----
-title: Text formatting
-slug: Web/JavaScript/Guide/Text_formatting
-page-type: guide
----
-
-{{jsSidebar("JavaScript Guide")}} {{PreviousNext("Web/JavaScript/Guide/Numbers_and_dates", "Web/JavaScript/Guide/Regular_expressions")}}
-
-This chapter introduces how to work with strings and text in JavaScript.
-
-## Strings
-
-JavaScript's [String](/en-US/docs/Glossary/String) type is used to represent textual data. It is a set of "elements" of 16-bit unsigned integer values (UTF-16 code units). Each element in the String occupies a position in the String. The first element is at index 0, the next at index 1, and so on. The length of a String is the number of elements in it. You can create strings using string literals or string objects.
-
-### String literals
-
-You can declare strings in source code using either single or double quotes:
-
-```js-nolint
-'foo'
-"bar"
-```
-
-More advanced strings can be created using escape sequences:
-
-#### Hexadecimal escape sequences
-
-The number after \x is interpreted as a [hexadecimal](https://en.wikipedia.org/wiki/Hexadecimal) number.
-
-```js-nolint
-"\xA9" // "©"
-```
-
-#### Unicode escape sequences
-
-The Unicode escape sequences require at least four hexadecimal digits following `\u`.
-
-```js-nolint
-"\u00A9" // "©"
-```
-
-#### Unicode code point escapes
-
-With Unicode code point escapes, any character can be escaped using hexadecimal numbers so that it is possible to use Unicode code points up to `0x10FFFF`. With the four-digit Unicode escapes it is often necessary to write the surrogate halves separately to achieve the same result.
-
-See also {{jsxref("String.fromCodePoint()")}} or {{jsxref("String.prototype.codePointAt()")}}.
-
-```js-nolint
-"\u{2F804}"
-
-// the same with simple Unicode escapes
-"\uD87E\uDC04"
-```
-
-### String objects
-
-The {{jsxref("String")}} object is a wrapper around the string primitive data type.
-
-```js
-const foo = new String("foo"); // Creates a String object
-console.log(foo); // [String: 'foo']
-typeof foo; // 'object'
-```
-
-You can call any of the methods of the `String` object on a string literal value—JavaScript automatically converts the string literal to a temporary `String` object, calls the method, then discards the temporary `String` object. You can also use the `length` property with a string literal.
-
-You should use string literals unless you specifically need to use a `String` object, because `String` objects can have counterintuitive behavior. For example:
-
-```js
-const firstString = "2 + 2"; // Creates a string literal value
-const secondString = new String("2 + 2"); // Creates a String object
-eval(firstString); // Returns the number 4
-eval(secondString); // Returns a String object containing "2 + 2"
-```
-
-A `String` object has one property, `length`, that indicates the number of UTF-16 code units in the string. For example, the following code assigns `helloLength` the value 13, because "Hello, World!" has 13 characters, each represented by one UTF-16 code unit. You can access each code unit using an array bracket style. You can't change individual characters because strings are immutable array-like objects:
-
-```js
-const hello = "Hello, World!";
-const helloLength = hello.length;
-hello[0] = "L"; // This has no effect, because strings are immutable
-hello[0]; // This returns "H"
-```
-
-Characters whose Unicode scalar values are greater than U+FFFF (such as some rare Chinese/Japanese/Korean/Vietnamese characters and some emoji) are stored in UTF-16 with two surrogate code units each. For example, a string containing the single character U+1F600 "Emoji grinning face" will have length 2. Accessing the individual code units in such a string using square brackets may have undesirable consequences such as the formation of strings with unmatched surrogate code units, in violation of the Unicode standard. (Examples should be added to this page after MDN bug 857438 is fixed.) See also {{jsxref("String.fromCodePoint()")}} or {{jsxref("String.prototype.codePointAt()")}}.
-
-A `String` object has a variety of methods: for example those that return a variation on the string itself, such as `substring` and `toUpperCase`.
-
-The following table summarizes the methods of {{jsxref("String")}} objects.
-
-<table class="standard-table">
-  <caption>
-    <h4 id="Methods_of_String">Methods of <code>String</code></h4>
-  </caption>
-  <thead>
-    <tr>
-      <th scope="col">Method</th>
-      <th scope="col">Description</th>
-    </tr>
-  </thead>
-  <tbody>
-    <tr>
-      <td>
-        {{jsxref("String/charAt", "charAt()")}}, {{jsxref("String/charCodeAt", "charCodeAt()")}},
-        {{jsxref("String/codePointAt", "codePointAt()")}}
-      </td>
-      <td>
-        Return the character or character code at the specified position in
-        string.
-      </td>
-    </tr>
-    <tr>
-      <td>
-        {{jsxref("String/indexOf", "indexOf()")}},
-        {{jsxref("String/lastIndexOf", "lastIndexOf()")}}
-      </td>
-      <td>
-        Return the position of specified substring in the string or last
-        position of specified substring, respectively.
-      </td>
-    </tr>
-    <tr>
-      <td>
-        {{jsxref("String/startsWith", "startsWith()")}},
-        {{jsxref("String/endsWith", "endsWith()")}},
-        {{jsxref("String/includes", "includes()")}}
-      </td>
-      <td>
-        Returns whether or not the string starts, ends or contains a specified
-        string.
-      </td>
-    </tr>
-    <tr>
-      <td>{{jsxref("String/concat", "concat()")}}</td>
-      <td>Combines the text of two strings and returns a new string.</td>
-    </tr>
-    <tr>
-      <td>{{jsxref("String/split", "split()")}}</td>
-      <td>
-        Splits a <code>String</code> object into an array of strings by
-        separating the string into substrings.
-      </td>
-    </tr>
-    <tr>
-      <td>{{jsxref("String/slice", "slice()")}}</td>
-      <td>Extracts a section of a string and returns a new string.</td>
-    </tr>
-    <tr>
-      <td>
-        {{jsxref("String/substring", "substring()")}},
-        {{jsxref("String/substr", "substr()")}}
-      </td>
-      <td>
-        Return the specified subset of the string, either by specifying the
-        start and end indexes or the start index and a length.
-      </td>
-    </tr>
-    <tr>
-      <td>
-        {{jsxref("String/match", "match()")}}, {{jsxref("String/matchAll", "matchAll()")}},
-        {{jsxref("String/replace", "replace()")}}, {{jsxref("String/replaceAll", "replaceAll()")}},
-        {{jsxref("String/search", "search()")}}
-      </td>
-      <td>Work with regular expressions.</td>
-    </tr>
-    <tr>
-      <td>
-        {{jsxref("String/toLowerCase", "toLowerCase()")}},
-        {{jsxref("String/toUpperCase", "toUpperCase()")}}
-      </td>
-      <td>
-        <p>
-          Return the string in all lowercase or all uppercase, respectively.
-        </p>
-      </td>
-    </tr>
-    <tr>
-      <td>{{jsxref("String/normalize", "normalize()")}}</td>
-      <td>
-        Returns the Unicode Normalization Form of the calling string value.
-      </td>
-    </tr>
-    <tr>
-      <td>{{jsxref("String/repeat", "repeat()")}}</td>
-      <td>
-        Returns a string consisting of the elements of the object repeated the
-        given times.
-      </td>
-    </tr>
-    <tr>
-      <td>{{jsxref("String/trim", "trim()")}}</td>
-      <td>Trims whitespace from the beginning and end of the string.</td>
-    </tr>
-  </tbody>
-</table>
-
-### Multi-line template literals
-
-[Template literals](/en-US/docs/Web/JavaScript/Reference/Template_literals) are string literals allowing embedded expressions. You can use multi-line strings and string interpolation features with them.
-
-Template literals are enclosed by backtick ([grave accent](https://en.wikipedia.org/wiki/Grave_accent)) characters (`` ` ``) instead of double or single quotes. Template literals can contain placeholders. These are indicated by the dollar sign and curly braces (`${expression}`).
-
-#### Multi-lines
-
-Any new line characters inserted in the source are part of the template literal. Using normal strings, you would have to use the following syntax in order to get multi-line strings:
-
-```js
-console.log(
-  "string text line 1\n\
-string text line 2",
-);
-// "string text line 1
-// string text line 2"
-```
-
-To get the same effect with multi-line strings, you can now write:
-
-```js
-console.log(`string text line 1
-string text line 2`);
-// "string text line 1
-// string text line 2"
-```
-
-#### Embedded expressions
-
-In order to embed expressions within normal strings, you would use the following syntax:
-
-```js
-const five = 5;
-const ten = 10;
-console.log(
-  "Fifteen is " + (five + ten) + " and not " + (2 * five + ten) + ".",
-);
-// "Fifteen is 15 and not 20."
-```
-
-Now, with template literals, you are able to make use of the syntactic sugar making substitutions like this more readable:
-
-```js
-const five = 5;
-const ten = 10;
-console.log(`Fifteen is ${five + ten} and not ${2 * five + ten}.`);
-// "Fifteen is 15 and not 20."
-```
-
-For more information, read about [Template literals](/en-US/docs/Web/JavaScript/Reference/Template_literals) in the [JavaScript reference](/en-US/docs/Web/JavaScript/Reference).
-
-## Internationalization
-
-The {{jsxref("Intl")}} object is the namespace for the ECMAScript Internationalization API, which provides language sensitive string comparison, number formatting, and date and time formatting. The constructors for {{jsxref("Intl.Collator")}}, {{jsxref("Intl.NumberFormat")}}, and {{jsxref("Intl.DateTimeFormat")}} objects are properties of the `Intl` object.
-
-### Date and time formatting
-
-The {{jsxref("Intl.DateTimeFormat")}} object is useful for formatting date and time. The following formats a date for English as used in the United States. (The result is different in another time zone.)
-
-```js
-// July 17, 2014 00:00:00 UTC:
-const july172014 = new Date("2014-07-17");
-
-const options = {
-  year: "2-digit",
-  month: "2-digit",
-  day: "2-digit",
-  hour: "2-digit",
-  minute: "2-digit",
-  timeZoneName: "short",
-};
-const americanDateTime = new Intl.DateTimeFormat("en-US", options).format;
-
-// Local timezone vary depending on your settings
-// In CEST, logs: 07/17/14, 02:00 AM GMT+2
-// In PDT, logs: 07/16/14, 05:00 PM GMT-7
-console.log(americanDateTime(july172014));
-```
-
-### Number formatting
-
-The {{jsxref("Intl.NumberFormat")}} object is useful for formatting numbers, for example currencies.
-
-```js
-const gasPrice = new Intl.NumberFormat("en-US", {
-  style: "currency",
-  currency: "USD",
-  minimumFractionDigits: 3,
-});
-
-console.log(gasPrice.format(5.259)); // $5.259
-
-const hanDecimalRMBInChina = new Intl.NumberFormat("zh-CN-u-nu-hanidec", {
-  style: "currency",
-  currency: "CNY",
-});
-
-console.log(hanDecimalRMBInChina.format(1314.25)); // ￥ 一,三一四.二五
-```
-
-### Collation
-
-The {{jsxref("Intl.Collator")}} object is useful for comparing and sorting strings.
-
-For example, there are actually two different sort orders in German, _phonebook_ and _dictionary_. Phonebook sort emphasizes sound, and it's as if "ä", "ö", and so on were expanded to "ae", "oe", and so on prior to sorting.
-
-```js
-const names = ["Hochberg", "Hönigswald", "Holzman"];
-
-const germanPhonebook = new Intl.Collator("de-DE-u-co-phonebk");
-
-// as if sorting ["Hochberg", "Hoenigswald", "Holzman"]:
-console.log(names.sort(germanPhonebook.compare).join(", "));
-// "Hochberg, Hönigswald, Holzman"
-```
-
-Some German words conjugate with extra umlauts, so in dictionaries it's sensible to order ignoring umlauts (except when ordering words differing _only_ by umlauts: _schon_ before _schön_).
-
-```js
-const germanDictionary = new Intl.Collator("de-DE-u-co-dict");
-
-// as if sorting ["Hochberg", "Honigswald", "Holzman"]:
-console.log(names.sort(germanDictionary.compare).join(", "));
-// "Hochberg, Holzman, Hönigswald"
-```
-
-For more information about the {{jsxref("Intl")}} API, see also [Introducing the JavaScript Internationalization API](https://hacks.mozilla.org/2014/12/introducing-the-javascript-internationalization-api/).
-
-{{PreviousNext("Web/JavaScript/Guide/Numbers_and_dates", "Web/JavaScript/Guide/Regular_expressions")}}
diff --git a/files/en-us/web/javascript/guide/using_classes/index.md b/files/en-us/web/javascript/guide/using_classes/index.md
index bc279fb3b7ee37f..28f7b6b09c00428 100644
--- a/files/en-us/web/javascript/guide/using_classes/index.md
+++ b/files/en-us/web/javascript/guide/using_classes/index.md
@@ -16,7 +16,7 @@ This chapter assumes that you are already somewhat familiar with JavaScript and
 
 ## Overview of classes
 
-If you have some hands-on experience with JavaScript, or have followed along with the guide, you probably have already used classes, even if you haven't created one. For example, this [may seem familiar to you](/en-US/docs/Web/JavaScript/Guide/Numbers_and_dates):
+If you have some hands-on experience with JavaScript, or have followed along with the guide, you probably have already used classes, even if you haven't created one. For example, this [may seem familiar to you](/en-US/docs/Web/JavaScript/Guide/Representing_dates_times):
 
 ```js
 const bigDay = new Date(2019, 6, 19);
diff --git a/files/en-us/web/javascript/index.md b/files/en-us/web/javascript/index.md
index 27d4180a6cf2f14..8eb66ce4904f71e 100644
--- a/files/en-us/web/javascript/index.md
+++ b/files/en-us/web/javascript/index.md
@@ -74,7 +74,7 @@ Learn how to program in JavaScript from the ground up with our beginner's tutori
 Browse the complete [JavaScript reference](/en-US/docs/Web/JavaScript/Reference) documentation.
 
 - [Standard objects](/en-US/docs/Web/JavaScript/Reference/Global_Objects)
-  - : Get to know standard built-in objects {{jsxref("Array")}}, {{jsxref("Boolean")}}, {{jsxref("Date")}}, {{jsxref("Error")}}, {{jsxref("Function")}}, {{jsxref("JSON")}}, {{jsxref("Math")}}, {{jsxref("Number")}}, {{jsxref("Object")}}, {{jsxref("RegExp")}}, {{jsxref("String")}}, {{jsxref("Map")}}, {{jsxref("Set")}}, {{jsxref("WeakMap")}}, {{jsxref("WeakSet")}}, and others.
+  - : Get to know standard built-in objects: {{jsxref("Array")}}, {{jsxref("Boolean")}}, {{jsxref("Error")}}, {{jsxref("Function")}}, {{jsxref("JSON")}}, {{jsxref("Math")}}, {{jsxref("Number")}}, {{jsxref("Object")}}, {{jsxref("RegExp")}}, {{jsxref("String")}}, {{jsxref("Map")}}, {{jsxref("Set")}}, {{jsxref("WeakMap")}}, {{jsxref("WeakSet")}}, and others.
 - [Expressions and operators](/en-US/docs/Web/JavaScript/Reference/Operators)
   - : Learn more about the behavior of JavaScript's operators {{jsxref("Operators/instanceof", "instanceof")}}, {{jsxref("Operators/typeof", "typeof")}}, {{jsxref("Operators/new", "new")}}, {{jsxref("Operators/this", "this")}}, the [operator precedence](/en-US/docs/Web/JavaScript/Reference/Operators/Operator_precedence), and more.
 - [Statements and declarations](/en-US/docs/Web/JavaScript/Reference/Statements)
diff --git a/files/en-us/web/javascript/language_overview/index.md b/files/en-us/web/javascript/language_overview/index.md
index 423a1ade6b3e2da..4a61a7c4db0834f 100644
--- a/files/en-us/web/javascript/language_overview/index.md
+++ b/files/en-us/web/javascript/language_overview/index.md
@@ -26,7 +26,7 @@ Everything else is known as an [Object](/en-US/docs/Web/JavaScript/Data_structur
 
 - {{jsxref("Function")}}
 - {{jsxref("Array")}}
-- {{jsxref("Date")}}
+- {{jsxref("Map")}}
 - {{jsxref("RegExp")}}
 - {{jsxref("Error")}}
 
diff --git a/files/en-us/web/javascript/reference/classes/public_class_fields/index.md b/files/en-us/web/javascript/reference/classes/public_class_fields/index.md
index eabe0329c8e2d70..4db72aca2439121 100644
--- a/files/en-us/web/javascript/reference/classes/public_class_fields/index.md
+++ b/files/en-us/web/javascript/reference/classes/public_class_fields/index.md
@@ -7,7 +7,7 @@ browser-compat: javascript.classes.public_class_fields
 
 {{jsSidebar("Classes")}}
 
-**Public fields** are writable, enumerable, and configurable properties. As such, unlike their private counterparts, they participate in prototype inheritance.
+**Public fields** are writable, enumerable, and configurable properties defined on each class instance or class constructor.
 
 ## Syntax
 
@@ -177,7 +177,7 @@ const instance2 = new DerivedWithConstructor(); // Logs 1
 
 ### Using class fields
 
-Class fields cannot depend on arguments of the constructor, so field initializers usually evaluate to the same value for each instance (unless the same expression can evaluate to different values each time, such as {{jsxref("Date.now()")}} or object initializers).
+Class fields cannot depend on arguments of the constructor, so field initializers usually evaluate to the same value for each instance (unless the same expression can evaluate to different values each time, such as {{jsxref("Math.random()")}} or object initializers).
 
 ```js example-bad
 class Person {
diff --git a/files/en-us/web/javascript/reference/errors/identifier_after_number/index.md b/files/en-us/web/javascript/reference/errors/identifier_after_number/index.md
index 611be8a22a681c1..26fe9e474635760 100644
--- a/files/en-us/web/javascript/reference/errors/identifier_after_number/index.md
+++ b/files/en-us/web/javascript/reference/errors/identifier_after_number/index.md
@@ -42,9 +42,6 @@ const 1life = "foo";
 
 const foo = 1life;
 // SyntaxError: identifier starts immediately after numeric literal
-
-alert(1.foo);
-// SyntaxError: identifier starts immediately after numeric literal
 ```
 
 You will need to rename your variable to avoid the leading number.
@@ -54,6 +51,26 @@ const life1 = "foo";
 const foo = life1;
 ```
 
+In JavaScript, there is a syntactic peculiarity when calling properties or methods on numbers. If you want to call a method on an integer, you cannot immediately use a dot after the number because the dot is interpreted as the start of a decimal fraction, causing the parser to see the method's name as an identifier immediately after a number literal. To avoid this, you need to either wrap the number in parentheses or use a double dot, where the first dot is a decimal point for the number literal and the second dot is the property accessor.
+
+```js-nolint example-bad
+alert(typeof 1.toString())
+// SyntaxError: identifier starts immediately after numeric literal
+```
+
+Correct ways to call methods on numbers:
+
+```js-nolint example-good
+// Wrap the number in parentheses
+alert(typeof (1).toString());
+
+// Add an extra dot for the number literal
+alert(typeof 2..toString());
+
+// Use square brackets
+alert(typeof 3["toString"]());
+```
+
 ## See also
 
 - [Lexical grammar](/en-US/docs/Web/JavaScript/Reference/Lexical_grammar)
diff --git a/files/en-us/web/javascript/reference/global_objects/array/find/index.md b/files/en-us/web/javascript/reference/global_objects/array/find/index.md
index 7857b6fc9543dae..33f1af624771ae4 100644
--- a/files/en-us/web/javascript/reference/global_objects/array/find/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/array/find/index.md
@@ -86,9 +86,9 @@ const result = inventory.find(({ name }) => name === "cherries");
 console.log(result); // { name: 'cherries', quantity: 5 }
 ```
 
-### Find a prime number in an array
+### Find the first prime number in an array
 
-The following example finds an element in the array that is a prime number (or returns {{jsxref("undefined")}} if there is no prime number):
+The following example returns the first element in the array that is a prime number, or {{jsxref("undefined")}} if there is no prime number.
 
 ```js
 function isPrime(element, index, array) {
diff --git a/files/en-us/web/javascript/reference/global_objects/array/findindex/index.md b/files/en-us/web/javascript/reference/global_objects/array/findindex/index.md
index d182016756f7205..0b01a1b63e6d3ec 100644
--- a/files/en-us/web/javascript/reference/global_objects/array/findindex/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/array/findindex/index.md
@@ -48,7 +48,7 @@ The `findIndex()` method is [generic](/en-US/docs/Web/JavaScript/Reference/Globa
 
 ## Examples
 
-### Find the index of a prime number in an array
+### Find the index of the first prime number in an array
 
 The following example returns the index of the first element in the array that is a prime number, or `-1` if there is no prime number.
 
diff --git a/files/en-us/web/javascript/reference/global_objects/array/tolocalestring/index.md b/files/en-us/web/javascript/reference/global_objects/array/tolocalestring/index.md
index b6bec81d1d68740..335e063886c9340 100644
--- a/files/en-us/web/javascript/reference/global_objects/array/tolocalestring/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/array/tolocalestring/index.md
@@ -27,7 +27,7 @@ toLocaleString(locales, options)
 - `locales` {{optional_inline}}
   - : A string with a BCP 47 language tag, or an array of such strings. For the general form and interpretation of the `locales` argument, see [the parameter description on the `Intl` main page](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl#locales_argument).
 - `options` {{optional_inline}}
-  - : An object with configuration properties. For numbers, see {{jsxref("Number.prototype.toLocaleString()")}}; for dates, see {{jsxref("Date.prototype.toLocaleString()")}}.
+  - : An object with configuration properties. What you can pass here depends on what elements are being converted. For example, for numbers, see {{jsxref("Number.prototype.toLocaleString()")}}.
 
 ### Return value
 
@@ -47,15 +47,7 @@ The `toLocaleString()` method is [generic](/en-US/docs/Web/JavaScript/Reference/
 
 ### Using locales and options
 
-The elements of the array are converted to strings using their
-`toLocaleString` methods.
-
-- `Object`: {{jsxref("Object.prototype.toLocaleString()")}}
-- `Number`: {{jsxref("Number.prototype.toLocaleString()")}}
-- `Date`: {{jsxref("Date.prototype.toLocaleString()")}}
-
-Always display the currency for the strings and numbers in the `prices`
-array:
+The elements of the array are converted to strings using their `toLocaleString` methods. For example, this snippet implicitly calls the {{jsxref("Number.prototype.toLocaleString()")}} method to display the currency for the strings and numbers in the `prices` array:
 
 ```js
 const prices = ["￥7", 500, 8123, 12];
@@ -64,8 +56,6 @@ prices.toLocaleString("ja-JP", { style: "currency", currency: "JPY" });
 // "￥7,￥500,￥8,123,￥12"
 ```
 
-For more examples, see also the [`Intl.NumberFormat`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/NumberFormat) and [`Intl.DateTimeFormat`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat) pages.
-
 ### Using toLocaleString() on sparse arrays
 
 `toLocaleString()` treats empty slots the same as `undefined` and produces an extra separator:
@@ -108,4 +98,4 @@ console.log(Array.prototype.toLocaleString.call(arrayLike));
 - {{jsxref("Intl.ListFormat")}}
 - {{jsxref("Object.prototype.toLocaleString()")}}
 - {{jsxref("Number.prototype.toLocaleString()")}}
-- {{jsxref("Date.prototype.toLocaleString()")}}
+- {{jsxref("Temporal/PlainDate/toLocaleString", "Temporal.PlainDate.prototype.toLocaleString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/atomics/index.md b/files/en-us/web/javascript/reference/global_objects/atomics/index.md
index a1c4a9fb4bbe664..e7d50665472a446 100644
--- a/files/en-us/web/javascript/reference/global_objects/atomics/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/atomics/index.md
@@ -104,7 +104,9 @@ const sab = new SharedArrayBuffer(1024);
 const int32 = new Int32Array(sab);
 ```
 
-A reading thread is sleeping and waiting on location 0 which is expected to be 0. As long as that is true, it will not go on. However, once the writing thread has stored a new value, it will be notified by the writing thread and return the new value (123).
+A reading thread is sleeping and waiting on location 0 because the provided value matches what is stored at the provided index.
+The reading thread will not move on until the writing thread has called `Atomics.notify()` on position 0 of the provided typed array.
+Note that if, after being woken up, the value of location 0 has not been changed by the writing thread, the reading thread will **not** go back to sleep, but will continue on.
 
 ```js
 Atomics.wait(int32, 0, 0);
diff --git a/files/en-us/web/javascript/reference/global_objects/atomics/notify/index.md b/files/en-us/web/javascript/reference/global_objects/atomics/notify/index.md
index eb6a92727c16cd0..dd3d6bede9ec91e 100644
--- a/files/en-us/web/javascript/reference/global_objects/atomics/notify/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/atomics/notify/index.md
@@ -52,9 +52,9 @@ const sab = new SharedArrayBuffer(1024);
 const int32 = new Int32Array(sab);
 ```
 
-A reading thread is sleeping and waiting on location 0 which is expected to be 0. As
-long as that is true, it will not go on. However, once the writing thread has stored a
-new value, it will be notified by the writing thread and return the new value (123).
+A reading thread is sleeping and waiting on location 0 because the provided `value` matches what is stored at the provided `index`.
+The reading thread will not move on until the writing thread has called `Atomics.notify()` on position 0 of the provided `typedArray`.
+Note that if, after being woken up, the value of location 0 has not been changed by the writing thread, the reading thread will **not** go back to sleep, but will continue on.
 
 ```js
 Atomics.wait(int32, 0, 0);
diff --git a/files/en-us/web/javascript/reference/global_objects/atomics/wait/index.md b/files/en-us/web/javascript/reference/global_objects/atomics/wait/index.md
index b5894231a7d8368..070c7e49a174bd7 100644
--- a/files/en-us/web/javascript/reference/global_objects/atomics/wait/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/atomics/wait/index.md
@@ -38,6 +38,10 @@ Atomics.wait(typedArray, index, value, timeout)
 
 A string which is either `"ok"`, `"not-equal"`, or `"timed-out"`.
 
+- `"ok"` is returned if woken up by a call to `Atomics.notify()`, **regardless of if the expected value has changed**
+- `"not-equal"` is returned immediately if the initial `value` does not equal what is stored at `index`
+- `"timed-out"` is returned if a sleeping wait exceeds the specified `timeout` without being woken up by `Atomics.notify()`
+
 ### Exceptions
 
 - {{jsxref("TypeError")}}
@@ -58,9 +62,9 @@ const sab = new SharedArrayBuffer(1024);
 const int32 = new Int32Array(sab);
 ```
 
-A reading thread is sleeping and waiting on location 0 which is expected to be 0. As
-long as that is true, it will not go on. However, once the writing thread has stored a
-new value, it will be notified by the writing thread and return the new value (123).
+A reading thread is sleeping and waiting on location 0 because the provided `value` matches what is stored at the provided `index`.
+The reading thread will not move on until the writing thread has called `Atomics.notify()` on position 0 of the provided `typedArray`.
+Note that if, after being woken up, the value of location 0 has not been changed by the writing thread, the reading thread will **not** go back to sleep, but will continue on.
 
 ```js
 Atomics.wait(int32, 0, 0);
diff --git a/files/en-us/web/javascript/reference/global_objects/bigint/index.md b/files/en-us/web/javascript/reference/global_objects/bigint/index.md
index 726a8345d7bbabd..56b5f333ec3e9fa 100644
--- a/files/en-us/web/javascript/reference/global_objects/bigint/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/bigint/index.md
@@ -7,7 +7,7 @@ browser-compat: javascript.builtins.BigInt
 
 {{JSRef}}
 
-**`BigInt`** values represent numeric values which are [too large](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/MAX_SAFE_INTEGER) to be represented by the `number` {{Glossary("Primitive", "primitive")}}.
+**`BigInt`** values represent integer values which are [too high](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/MAX_SAFE_INTEGER) or [too low](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/MIN_SAFE_INTEGER) to be represented by the `number` {{Glossary("Primitive", "primitive")}}.
 
 ## Description
 
diff --git a/files/en-us/web/javascript/reference/global_objects/bigint/tolocalestring/index.md b/files/en-us/web/javascript/reference/global_objects/bigint/tolocalestring/index.md
index 17c2730f718b872..527b21baec1c088 100644
--- a/files/en-us/web/javascript/reference/global_objects/bigint/tolocalestring/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/bigint/tolocalestring/index.md
@@ -7,7 +7,7 @@ browser-compat: javascript.builtins.BigInt.toLocaleString
 
 {{JSRef}}
 
-The **`toLocaleString()`** method of {{jsxref("BigInt")}} values returns a string with a language-sensitive representation of this BigInt. In implementations with [`Intl.NumberFormat` API](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/NumberFormat) support, this method simply calls `Intl.NumberFormat`.
+The **`toLocaleString()`** method of {{jsxref("BigInt")}} values returns a string with a language-sensitive representation of this BigInt. In implementations with [`Intl.NumberFormat` API](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/NumberFormat) support, this method delegates to `Intl.NumberFormat`.
 
 Every time `toLocaleString` is called, it has to perform a search in a big database of localization strings, which is potentially inefficient. When the method is called many times with the same arguments, it is better to create a {{jsxref("Intl.NumberFormat")}} object and use its {{jsxref("Intl/NumberFormat/format", "format()")}} method, because a `NumberFormat` object remembers the arguments passed to it and may decide to cache a slice of the database, so future `format` calls can search for localization strings within a more constrained context.
 
diff --git a/files/en-us/web/javascript/reference/global_objects/date/index.md b/files/en-us/web/javascript/reference/global_objects/date/index.md
index f296369a003378d..54c4a7cbc2a9ae7 100644
--- a/files/en-us/web/javascript/reference/global_objects/date/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/date/index.md
@@ -10,7 +10,7 @@ browser-compat: javascript.builtins.Date
 JavaScript **`Date`** objects represent a single moment in time in a platform-independent format. `Date` objects encapsulate an integral number that represents milliseconds since the midnight at the beginning of January 1, 1970, UTC (the _epoch_).
 
 > [!NOTE]
-> TC39 is working on [Temporal](https://tc39.es/proposal-temporal/docs/index.html), a new Date/Time API. Read more about it on the [Igalia blog](https://blogs.igalia.com/compilers/2020/06/23/dates-and-times-in-javascript/). It is not yet ready for production use!
+> With the introduction of the {{jsxref("Temporal")}} API, the `Date` object is considered a legacy feature. Consider using `Temporal` for new code and migrate existing code over to it if possible (check the [browser compatibility](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#browser_compatibility). We will be writing a usage guide soon!
 
 ## Description
 
@@ -275,7 +275,7 @@ These properties are defined on `Date.prototype` and shared by all `Date` instan
 - {{jsxref("Date.prototype.toISOString()")}}
   - : Converts a date to a string following the ISO 8601 Extended Format.
 - {{jsxref("Date.prototype.toJSON()")}}
-  - : Returns a string representing the `Date` using {{jsxref("Date/toISOString", "toISOString()")}}. Intended for use by {{jsxref("JSON.stringify()")}}.
+  - : Returns a string representing the `Date` using {{jsxref("Date/toISOString", "toISOString()")}}. Intended to be implicitly called by {{jsxref("JSON.stringify()")}}.
 - {{jsxref("Date.prototype.toLocaleDateString()")}}
   - : Returns a string with a locality sensitive representation of the date portion of this date based on system settings.
 - {{jsxref("Date.prototype.toLocaleString()")}}
@@ -284,6 +284,8 @@ These properties are defined on `Date.prototype` and shared by all `Date` instan
   - : Returns a string with a locality-sensitive representation of the time portion of this date, based on system settings.
 - {{jsxref("Date.prototype.toString()")}}
   - : Returns a string representing the specified `Date` object. Overrides the {{jsxref("Object.prototype.toString()")}} method.
+- {{jsxref("Date.prototype.toTemporalInstant()")}} {{experimental_inline}}
+  - : Returns a new {{jsxref("Temporal.Instant")}} object with the same {{jsxref("Temporal/Instant/epochMilliseconds", "epochMilliseconds")}} value as this date's [timestamp](#the_epoch_timestamps_and_invalid_date).
 - {{jsxref("Date.prototype.toTimeString()")}}
   - : Returns the "time" portion of the `Date` as a human-readable string.
 - {{jsxref("Date.prototype.toUTCString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/date/tolocaledatestring/index.md b/files/en-us/web/javascript/reference/global_objects/date/tolocaledatestring/index.md
index e0cafc2310ff220..e842f57bddac281 100644
--- a/files/en-us/web/javascript/reference/global_objects/date/tolocaledatestring/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/date/tolocaledatestring/index.md
@@ -7,7 +7,7 @@ browser-compat: javascript.builtins.Date.toLocaleDateString
 
 {{JSRef}}
 
-The **`toLocaleDateString()`** method of {{jsxref("Date")}} instances returns a string with a language-sensitive representation of the date portion of this date in the local timezone. In implementations with [`Intl.DateTimeFormat` API](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat) support, this method simply calls `Intl.DateTimeFormat`.
+The **`toLocaleDateString()`** method of {{jsxref("Date")}} instances returns a string with a language-sensitive representation of the date portion of this date in the local timezone. In implementations with [`Intl.DateTimeFormat` API](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat) support, this method delegates to `Intl.DateTimeFormat`.
 
 Every time `toLocaleString` is called, it has to perform a search in a big database of localization strings, which is potentially inefficient. When the method is called many times with the same arguments, it is better to create a {{jsxref("Intl.DateTimeFormat")}} object and use its {{jsxref("Intl/DateTimeFormat/format", "format()")}} method, because a `DateTimeFormat` object remembers the arguments passed to it and may decide to cache a slice of the database, so future `format` calls can search for localization strings within a more constrained context.
 
diff --git a/files/en-us/web/javascript/reference/global_objects/date/tolocalestring/index.md b/files/en-us/web/javascript/reference/global_objects/date/tolocalestring/index.md
index fafc7e069b86eb8..06f1693de776b7d 100644
--- a/files/en-us/web/javascript/reference/global_objects/date/tolocalestring/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/date/tolocalestring/index.md
@@ -7,7 +7,7 @@ browser-compat: javascript.builtins.Date.toLocaleString
 
 {{JSRef}}
 
-The **`toLocaleString()`** method of {{jsxref("Date")}} instances returns a string with a language-sensitive representation of this date in the local timezone. In implementations with [`Intl.DateTimeFormat` API](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat) support, this method simply calls `Intl.DateTimeFormat`.
+The **`toLocaleString()`** method of {{jsxref("Date")}} instances returns a string with a language-sensitive representation of this date in the local timezone. In implementations with [`Intl.DateTimeFormat` API](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat) support, this method delegates to `Intl.DateTimeFormat`.
 
 Every time `toLocaleString` is called, it has to perform a search in a big database of localization strings, which is potentially inefficient. When the method is called many times with the same arguments, it is better to create a {{jsxref("Intl.DateTimeFormat")}} object and use its {{jsxref("Intl/DateTimeFormat/format", "format()")}} method, because a `DateTimeFormat` object remembers the arguments passed to it and may decide to cache a slice of the database, so future `format` calls can search for localization strings within a more constrained context.
 
diff --git a/files/en-us/web/javascript/reference/global_objects/date/tolocaletimestring/index.md b/files/en-us/web/javascript/reference/global_objects/date/tolocaletimestring/index.md
index 8e23159d839150d..232301895eb9ee9 100644
--- a/files/en-us/web/javascript/reference/global_objects/date/tolocaletimestring/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/date/tolocaletimestring/index.md
@@ -7,7 +7,7 @@ browser-compat: javascript.builtins.Date.toLocaleTimeString
 
 {{JSRef}}
 
-The **`toLocaleTimeString()`** method of {{jsxref("Date")}} instances returns a string with a language-sensitive representation of the time portion of this date in the local timezone. In implementations with [`Intl.DateTimeFormat` API](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat) support, this method simply calls `Intl.DateTimeFormat`.
+The **`toLocaleTimeString()`** method of {{jsxref("Date")}} instances returns a string with a language-sensitive representation of the time portion of this date in the local timezone. In implementations with [`Intl.DateTimeFormat` API](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat) support, this method delegates to `Intl.DateTimeFormat`.
 
 Every time `toLocaleTimeString` is called, it has to perform a search in a big database of localization strings, which is potentially inefficient. When the method is called many times with the same arguments, it is better to create a {{jsxref("Intl.DateTimeFormat")}} object and use its {{jsxref("Intl/DateTimeFormat/format", "format()")}} method, because a `DateTimeFormat` object remembers the arguments passed to it and may decide to cache a slice of the database, so future `format` calls can search for localization strings within a more constrained context.
 
diff --git a/files/en-us/web/javascript/reference/global_objects/date/totemporalinstant/index.md b/files/en-us/web/javascript/reference/global_objects/date/totemporalinstant/index.md
new file mode 100644
index 000000000000000..b0b90de73c3792f
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/date/totemporalinstant/index.md
@@ -0,0 +1,61 @@
+---
+title: Date.prototype.toTemporalInstant()
+slug: Web/JavaScript/Reference/Global_Objects/Date/toTemporalInstant
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Date.toTemporalInstant
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toTemporalInstant()`** method of {{jsxref("Date")}} instances returns a new {{jsxref("Temporal.Instant")}} object with the same {{jsxref("Temporal/Instant/epochMilliseconds", "epochMilliseconds")}} value as this date's [timestamp](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date#the_epoch_timestamps_and_invalid_date).
+
+Use this method to convert legacy `Date` values to the `Temporal` API, then further convert it to other {{jsxref("Temporal")}} classes as necessary.
+
+## Syntax
+
+```js-nolint
+toTemporalInstant()
+```
+
+### Parameters
+
+None.
+
+### Return value
+
+A new {{jsxref("Temporal.Instant")}} object with the same {{jsxref("Temporal/Instant/epochMilliseconds", "epochMilliseconds")}} value as this date's timestamp. Its microsecond and nanosecond components are always `0`.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown if the date is [invalid](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date#the_epoch_timestamps_and_invalid_date) (it has a timestamp of `NaN`).
+
+## Examples
+
+### Using toTemporalInstant()
+
+```js
+const legacyDate = new Date("2021-07-01T12:34:56.789Z");
+const instant = legacyDate.toTemporalInstant();
+
+// Further convert it to other objects
+const zdt = instant.toZonedDateTimeISO("UTC");
+const date = zdt.toPlainDate();
+console.log(date.toString()); // 2021-07-01
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Instant")}}
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/Instant/fromEpochMilliseconds", "Temporal.Instant.fromEpochMilliseconds()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/eval/index.md b/files/en-us/web/javascript/reference/global_objects/eval/index.md
index d05bc71853619fb..a29bece55fcdf7c 100644
--- a/files/en-us/web/javascript/reference/global_objects/eval/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/eval/index.md
@@ -192,7 +192,7 @@ Consider this code:
 function looseJsonParse(obj) {
   return eval(`(${obj})`);
 }
-console.log(looseJsonParse("{ a: 4 - 1, b: function () {}, c: new Date() }"));
+console.log(looseJsonParse("{ a: 4 - 1, b: function () {}, c: new Map() }"));
 ```
 
 Simply using indirect eval and forcing strict mode can make the code much better:
@@ -201,22 +201,22 @@ Simply using indirect eval and forcing strict mode can make the code much better
 function looseJsonParse(obj) {
   return eval?.(`"use strict";(${obj})`);
 }
-console.log(looseJsonParse("{ a: 4 - 1, b: function () {}, c: new Date() }"));
+console.log(looseJsonParse("{ a: 4 - 1, b: function () {}, c: new Map() }"));
 ```
 
 The two code snippets above may seem to work the same way, but they do not; the first one using direct eval suffers from multiple problems.
 
-- It is a great deal slower, due to more scope inspections. Notice `c: new Date()` in the evaluated string. In the indirect eval version, the object is being evaluated in the global scope, so it is safe for the interpreter to assume that `Date` refers to the global `Date()` constructor instead of a local variable called `Date`. However, in the code using direct eval, the interpreter cannot assume this. For example, in the following code, `Date` in the evaluated string doesn't refer to `window.Date()`.
+- It is a great deal slower, due to more scope inspections. Notice `c: new Map()` in the evaluated string. In the indirect eval version, the object is being evaluated in the global scope, so it is safe for the interpreter to assume that `Map` refers to the global `Map()` constructor instead of a local variable called `Map`. However, in the code using direct eval, the interpreter cannot assume this. For example, in the following code, `Map` in the evaluated string doesn't refer to `window.Map()`.
 
   ```js
   function looseJsonParse(obj) {
-    function Date() {}
+    class Map {}
     return eval(`(${obj})`);
   }
-  console.log(looseJsonParse(`{ a: 4 - 1, b: function () {}, c: new Date() }`));
+  console.log(looseJsonParse(`{ a: 4 - 1, b: function () {}, c: new Map() }`));
   ```
 
-  Thus, in the `eval()` version of the code, the browser is forced to make the expensive lookup call to check to see if there are any local variables called `Date()`.
+  Thus, in the `eval()` version of the code, the browser is forced to make the expensive lookup call to check to see if there are any local variables called `Map()`.
 
 - If not using strict mode, `var` declarations within the `eval()` source becomes variables in the surrounding scope. This leads to hard-to-debug issues if the string is acquired from external input, especially if there's an existing variable with the same name.
 - Direct eval can read and mutate bindings in the surrounding scope, which may lead to external input corrupting local data.
@@ -233,21 +233,13 @@ The difference between `eval()` and `Function()` is that the source string passe
 The `Function()` constructor is useful if you wish to create local bindings within your eval source, by passing the variables as parameter bindings.
 
 ```js
-function Date(n) {
-  return [
-    "Monday",
-    "Tuesday",
-    "Wednesday",
-    "Thursday",
-    "Friday",
-    "Saturday",
-    "Sunday",
-  ][n % 7 || 0];
+function add(a, b) {
+  return a + b;
 }
-function runCodeWithDateFunction(obj) {
-  return Function("Date", `"use strict";return (${obj});`)(Date);
+function runCodeWithAddFunction(obj) {
+  return Function("add", `"use strict";return (${obj});`)(add);
 }
-console.log(runCodeWithDateFunction("Date(5)")); // Saturday
+console.log(runCodeWithAddFunction("add(5, 7)")); // 12
 ```
 
 Both `eval()` and `Function()` implicitly evaluate arbitrary code, and are forbidden in strict [CSP](/en-US/docs/Web/HTTP/CSP) settings. There are also additional safer (and faster!) alternatives to `eval()` or `Function()` for common use-cases.
diff --git a/files/en-us/web/javascript/reference/global_objects/index.md b/files/en-us/web/javascript/reference/global_objects/index.md
index bd8819add21d8c9..5dd36ec400b14ff 100644
--- a/files/en-us/web/javascript/reference/global_objects/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/index.md
@@ -74,6 +74,7 @@ These are the base objects representing numbers, dates, and mathematical calcula
 - {{jsxref("BigInt")}}
 - {{jsxref("Math")}}
 - {{jsxref("Date")}}
+- {{jsxref("Temporal")}}
 
 ### Text processing
 
diff --git a/files/en-us/web/javascript/reference/global_objects/intl/collator/collator/index.md b/files/en-us/web/javascript/reference/global_objects/intl/collator/collator/index.md
index ca077462efc0163..5cea914b98bdc0c 100644
--- a/files/en-us/web/javascript/reference/global_objects/intl/collator/collator/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/intl/collator/collator/index.md
@@ -55,7 +55,7 @@ Intl.Collator(locales, options)
     - `localeMatcher`
       - : The locale matching algorithm to use. Possible values are `"lookup"` and `"best fit"`; the default is `"best fit"`. For information about this option, see [Locale identification and negotiation](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl#locale_identification_and_negotiation).
     - `collation`
-      - : Variant collations for certain locales, such as `"emoji"`, `"pinyin"`, `"stroke"`, and so on. For a list of supported collation types, see [`Intl.Locale.prototype.getCollations()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/Locale/getCollations#supported_collation_types); the default is `"default"`. This option can also be set through the `co` Unicode extension key; if both are provided, this `options` property takes precedence.
+      - : Variant collations for certain locales, such as `"emoji"`, `"pinyin"`, `"stroke"`, and so on. For a list of supported collation types, see [`Intl.supportedValuesOf()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/supportedValuesOf#supported_collation_types); the default is `"default"`. This option can also be set through the `co` Unicode extension key; if both are provided, this `options` property takes precedence.
     - `numeric`
       - : Whether numeric collation should be used, such that "1" < "2" < "10". Possible values are `true` and `false`; the default is `false`. This option can also be set through the `kn` Unicode extension key; if both are provided, this `options` property takes precedence.
     - `caseFirst`
diff --git a/files/en-us/web/javascript/reference/global_objects/intl/collator/index.md b/files/en-us/web/javascript/reference/global_objects/intl/collator/index.md
index 43ce7b0ce3d026a..75a17861b177057 100644
--- a/files/en-us/web/javascript/reference/global_objects/intl/collator/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/intl/collator/index.md
@@ -90,3 +90,4 @@ console.log(new Intl.Collator("sv", { sensitivity: "base" }).compare("ä", "a"))
 ## See also
 
 - {{jsxref("Intl")}}
+- {{jsxref("String.prototype.localeCompare()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/intl/collator/resolvedoptions/index.md b/files/en-us/web/javascript/reference/global_objects/intl/collator/resolvedoptions/index.md
index 35d47fcf7def884..8c148e706c3d4fe 100644
--- a/files/en-us/web/javascript/reference/global_objects/intl/collator/resolvedoptions/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/intl/collator/resolvedoptions/index.md
@@ -34,7 +34,7 @@ A new object with properties reflecting the options computed during the initiali
 - `ignorePunctuation`
   - : The value provided for this property in the `options` argument, with default filled in as needed. It is a boolean. The default is `true` for Thai (`th`) and `false` for all other languages.
 - `collation`
-  - : The value provided for this property in the `options` argument, or using the Unicode extension key `"co"`, with default filled in as needed. It is a supported [collation type](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/Locale/getCollations#supported_collation_types) for this locale. The default is `"default"`.
+  - : The value provided for this property in the `options` argument, or using the Unicode extension key `"co"`, with default filled in as needed. It is a supported [collation type](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/supportedValuesOf#supported_collation_types) for this locale. The default is `"default"`.
 - `numeric`
   - : The value provided for this property in the `options` argument, or using the Unicode extension key `"kn"`, with default filled in as needed. It is a boolean. The default is `false`. If the implementation does not support this Unicode extension key, this property is omitted.
 - `caseFirst`
diff --git a/files/en-us/web/javascript/reference/global_objects/intl/datetimeformat/datetimeformat/index.md b/files/en-us/web/javascript/reference/global_objects/intl/datetimeformat/datetimeformat/index.md
index c646588331233ac..8476044ae94a143 100644
--- a/files/en-us/web/javascript/reference/global_objects/intl/datetimeformat/datetimeformat/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/intl/datetimeformat/datetimeformat/index.md
@@ -51,9 +51,9 @@ Intl.DateTimeFormat(locales, options)
 - `localeMatcher`
   - : The locale matching algorithm to use. Possible values are `"lookup"` and `"best fit"`; the default is `"best fit"`. For information about this option, see [Locale identification and negotiation](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl#locale_identification_and_negotiation).
 - `calendar`
-  - : The calendar to use, such as `"chinese"`, `"gregory"`, `"persian"`, and so on. For a list of supported calendar types, see [`Intl.Locale.prototype.getCalendars()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/Locale/getCalendars#supported_calendar_types). This option can also be set through the `ca` Unicode extension key; if both are provided, this `options` property takes precedence.
+  - : The calendar to use, such as `"chinese"`, `"gregory"`, `"persian"`, and so on. For a list of supported calendar types, see [`Intl.supportedValuesOf()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/supportedValuesOf#supported_calendar_types). This option can also be set through the `ca` Unicode extension key; if both are provided, this `options` property takes precedence.
 - `numberingSystem`
-  - : The numbering system to use for number formatting, such as `"arab"`, `"hans"`, `"mathsans"`, and so on. For a list of supported numbering system types, see [`Intl.Locale.prototype.getNumberingSystems()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/Locale/getNumberingSystems#supported_numbering_system_types). This option can also be set through the `nu` Unicode extension key; if both are provided, this `options` property takes precedence.
+  - : The numbering system to use for number formatting, such as `"arab"`, `"hans"`, `"mathsans"`, and so on. For a list of supported numbering system types, see [`Intl.supportedValuesOf()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/supportedValuesOf#supported_numbering_system_types). This option can also be set through the `nu` Unicode extension key; if both are provided, this `options` property takes precedence.
 - `hour12`
   - : Whether to use 12-hour time (as opposed to 24-hour time). Possible values are `true` and `false`; the default is locale dependent. When `true`, this option sets `hourCycle` to either `"h11"` or `"h12"`, depending on the locale. When `false`, it sets `hourCycle` to `"h23"`. `hour12` overrides both the `hc` locale extension tag and the `hourCycle` option, should either or both of those be present.
 - `hourCycle`
@@ -131,31 +131,48 @@ Intl.DateTimeFormat(locales, options)
     > [!NOTE]
     > Timezone display may fall back to another format if a required string is unavailable. For example, the non-location formats should display the timezone without a specific country/city location like "Pacific Time", but may fall back to a timezone like "Los Angeles Time".
 
-The default value for each date-time component option is {{jsxref("undefined")}}, but if all component properties are {{jsxref("undefined")}}, then `year`, `month`, and `day` default to `"numeric"`. If any of the date-time component options is specified, then `dateStyle` and `timeStyle` must be `undefined`.
+##### Date-time component default values
 
-- `formatMatcher`
+If any of the date-time component options are specified, then `dateStyle` and `timeStyle` must be `undefined`. If all date-time component options and `dateStyle`/`timeStyle` are `undefined`, some default options for date-time components are set, which depend on the object that the formatting method was called with:
+
+- When formatting {{jsxref("Temporal.PlainDate")}} and {{jsxref("Date")}}, `year`, `month`, and `day` default to `"numeric"`.
+- When formatting {{jsxref("Temporal.PlainTime")}}, `hour`, `minute`, and `second` default to `"numeric"`.
+- When formatting {{jsxref("Temporal.PlainYearMonth")}}, `year` and `month` default to `"numeric"`.
+- When formatting {{jsxref("Temporal.PlainMonthDay")}}, `month` and `day` default to `"numeric"`.
+- When formatting {{jsxref("Temporal.PlainDateTime")}} and {{jsxref("Temporal.Instant")}}, `year`, `month`, `day`, `hour`, `minute`, and `second` default to `"numeric"`.
 
-  - : The format matching algorithm to use. Possible values are `"basic"` and `"best fit"`; the default is `"best fit"`. Implementations are required to support displaying at least the following subsets of date-time components:
+##### Format matching
 
-    - `weekday`, `year`, `month`, `day`, `hour`, `minute`, `second`
-    - `weekday`, `year`, `month`, `day`
-    - `year`, `month`, `day`
-    - `year`, `month`
-    - `month`, `day`
-    - `hour`, `minute`, `second`
-    - `hour`, `minute`
+Implementations are required to support displaying at least the following subsets of date-time components:
 
-    Implementations may support other subsets, and requests will be negotiated against all available subset-representation combinations to find the best match. The algorithm for `"best fit"` is implementation-defined, and `"basic"` is [defined by the spec](https://tc39.es/ecma402/#sec-basicformatmatcher). This option is only used when both `dateStyle` and `timeStyle` are `undefined` (so that each date-time component's format is individually customizable).
+- `weekday`, `year`, `month`, `day`, `hour`, `minute`, `second`
+- `weekday`, `year`, `month`, `day`
+- `year`, `month`, `day`
+- `year`, `month`
+- `month`, `day`
+- `hour`, `minute`, `second`
+- `hour`, `minute`
+
+The date-time component styles requested might not directly correspond to a valid format supported by the locale, so the format matcher allows you to specify how to match the requested styles to the closest supported format.
+
+- `formatMatcher`
+  - : The format matching algorithm to use. Possible values are `"basic"` and `"best fit"`; the default is `"best fit"`. The algorithm for `"best fit"` is implementation-defined, and `"basic"` is [defined by the spec](https://tc39.es/ecma402/#sec-basicformatmatcher). This option is only used when both `dateStyle` and `timeStyle` are `undefined` (so that each date-time component's format is individually customizable).
 
 #### Style shortcuts
 
 - `dateStyle`
-  - : The [date formatting style](https://cldr.unicode.org/translation/date-time/date-time-patterns#h.aa5zjyepm6vh) to use. Possible values are `"full"`, `"long"`, `"medium"`, and `"short"`. It expands to styles for `weekday`, `day`, `month`, `year`, and `era`, with the exact combination of values depending on the locale.
+  - : The [date formatting style](https://cldr.unicode.org/translation/date-time/date-time-patterns#h.aa5zjyepm6vh) to use. Possible values are `"full"`, `"long"`, `"medium"`, and `"short"`. It expands to styles for `weekday`, `day`, `month`, `year`, and `era`, with the exact combination of values depending on the locale. When formatting objects such as {{jsxref("Temporal.PlainDate")}}, {{jsxref("Temporal.PlainYearMonth")}}, and {{jsxref("Temporal.PlainMonthDay")}}, `dateStyle` will resolve to only those fields relevant to the object.
 - `timeStyle`
   - : The [time formatting style](https://cldr.unicode.org/translation/date-time/date-time-patterns#h.588vo3awdscu) to use. Possible values are `"full"`, `"long"`, `"medium"`, and `"short"`. It expands to styles for `hour`, `minute`, `second`, and `timeZoneName`, with the exact combination of values depending on the locale.
 
 > **Note:** `dateStyle` and `timeStyle` can be used with each other, but not with other date-time component options (e.g. `weekday`, `hour`, `month`, etc.).
 
+You can format different object types depending on which of the style shortcut options you include:
+
+- If the `dateStyle` is specified, then you can format {{jsxref("Temporal.PlainDate")}}, {{jsxref("Temporal.PlainYearMonth")}}, and {{jsxref("Temporal.PlainMonthDay")}} objects.
+- If the `timeStyle` is specified, then you can format {{jsxref("Temporal.PlainTime")}} objects.
+- If either `dateStyle` or `timeStyle` is specified, then you can format {{jsxref("Temporal.PlainDateTime")}} and {{jsxref("Date")}} objects.
+
 ### Return value
 
 A new `Intl.DateTimeFormat` object.
diff --git a/files/en-us/web/javascript/reference/global_objects/intl/datetimeformat/format/index.md b/files/en-us/web/javascript/reference/global_objects/intl/datetimeformat/format/index.md
index 33221b5114f43af..d306013d875fb25 100644
--- a/files/en-us/web/javascript/reference/global_objects/intl/datetimeformat/format/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/intl/datetimeformat/format/index.md
@@ -20,7 +20,13 @@ format(date)
 ### Parameters
 
 - `date`
-  - : The date to format.
+
+  - : The date to format. Can be a {{jsxref("Date")}} or {{jsxref("Temporal.PlainDateTime")}} object. Additionally can be a {{jsxref("Temporal.PlainTime")}}, {{jsxref("Temporal.PlainDate")}}, {{jsxref("Temporal.PlainYearMonth")}}, or {{jsxref("Temporal.PlainMonthDay")}} object if the `DateTimeFormat` object was configured to print at least one relevant part of the date.
+
+    > [!NOTE]
+    > A {{jsxref("Temporal.ZonedDateTime")}} object will always throw a `TypeError`; use {{jsxref("Temporal/ZonedDateTime/toLocaleString", "Temporal.ZonedDateTime.prototype.toLocaleString()")}} or convert it to a {{jsxref("Temporal.PlainDateTime")}} object instead.
+
+    Omitting it results in formatting the current date (as returned by {{jsxref("Date.now()")}}), which could be slightly confusing, so it is advisable to always explicitly pass a date.
 
 ### Return value
 
@@ -75,6 +81,3 @@ console.log(formatted.join("; "));
 ## See also
 
 - {{jsxref("Intl.DateTimeFormat")}}
-- {{jsxref("Date.prototype.toLocaleString()")}}
-- {{jsxref("Date.prototype.toLocaleDateString()")}}
-- {{jsxref("Date.prototype.toLocaleTimeString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/intl/datetimeformat/formatrange/index.md b/files/en-us/web/javascript/reference/global_objects/intl/datetimeformat/formatrange/index.md
index 0afc112a3b4ccf9..57cd7a96cd5b969 100644
--- a/files/en-us/web/javascript/reference/global_objects/intl/datetimeformat/formatrange/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/intl/datetimeformat/formatrange/index.md
@@ -23,9 +23,11 @@ formatRange(startDate, endDate)
 ### Parameters
 
 - `startDate`
-  - : A {{jsxref("Date")}} object representing the start of the date range.
+  - : The start of the date range. Can be a {{jsxref("Date")}} or {{jsxref("Temporal.PlainDateTime")}} object. Additionally can be a {{jsxref("Temporal.PlainTime")}}, {{jsxref("Temporal.PlainDate")}}, {{jsxref("Temporal.PlainYearMonth")}}, or {{jsxref("Temporal.PlainMonthDay")}} object if the `DateTimeFormat` object was configured to print at least one relevant part of the date.
+    > [!NOTE]
+    > A {{jsxref("Temporal.ZonedDateTime")}} object will always throw a `TypeError`; use {{jsxref("Temporal/ZonedDateTime/toLocaleString", "Temporal.ZonedDateTime.prototype.toLocaleString()")}} or convert it to a {{jsxref("Temporal.PlainDateTime")}} object instead.
 - `endDate`
-  - : A {{jsxref("Date")}} object representing the end of the date range.
+  - : The end of the date range. Must have the same type as `startDate`.
 
 ### Return value
 
diff --git a/files/en-us/web/javascript/reference/global_objects/intl/datetimeformat/formatrangetoparts/index.md b/files/en-us/web/javascript/reference/global_objects/intl/datetimeformat/formatrangetoparts/index.md
index fd06a3c8fb6add9..a6de8ca406443af 100644
--- a/files/en-us/web/javascript/reference/global_objects/intl/datetimeformat/formatrangetoparts/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/intl/datetimeformat/formatrangetoparts/index.md
@@ -7,8 +7,7 @@ browser-compat: javascript.builtins.Intl.DateTimeFormat.formatRangeToParts
 
 {{JSRef}}
 
-The **`formatRangeToParts()`** method of {{jsxref("Intl.DateTimeFormat")}} instances returns an array of locale-specific tokens representing each part of the formatted date
-range produced by this `Intl.DateTimeFormat` object.
+The **`formatRangeToParts()`** method of {{jsxref("Intl.DateTimeFormat")}} instances returns an array of objects representing each part of the formatted string that would be returned by {{jsxref("Intl/DatetimeFormat/formatRange", "formatRange()")}}. It is useful for building custom strings from the locale-specific tokens.
 
 {{EmbedInteractiveExample("pages/js/intl-datetimeformat-prototype-formatrangetoparts.html", "taller")}}
 
@@ -18,15 +17,33 @@ range produced by this `Intl.DateTimeFormat` object.
 formatRangeToParts(startDate, endDate)
 ```
 
-## Examples
+### Parameters
+
+- `startDate`
+  - : The start of the date range. Can be a {{jsxref("Date")}} or {{jsxref("Temporal.PlainDateTime")}} object. Additionally can be a {{jsxref("Temporal.PlainTime")}}, {{jsxref("Temporal.PlainDate")}}, {{jsxref("Temporal.PlainYearMonth")}}, or {{jsxref("Temporal.PlainMonthDay")}} object if the `DateTimeFormat` object was configured to print at least one relevant part of the date.
+    > [!NOTE]
+    > A {{jsxref("Temporal.ZonedDateTime")}} object will always throw a `TypeError`; use {{jsxref("Temporal/ZonedDateTime/toLocaleString", "Temporal.ZonedDateTime.prototype.toLocaleString()")}} or convert it to a {{jsxref("Temporal.PlainDateTime")}} object instead.
+- `endDate`
+  - : The end of the date range. Must have the same type as `startDate`.
+
+### Return value
+
+An {{jsxref("Array")}} of objects containing the formatted date range in parts. Each object has three properties, `type`, `value`, and `source`, each containing a string. The string concatenation of `value`, in the order provided, will result in the same string as {{jsxref("Intl/DateTimeFormat/formatRange", "formatRange()")}}. The `type` may have the same values as {{jsxref("Intl/DateTimeFormat/formatToParts", "formatToParts()")}}. The `source` can be one of the following:
+
+- `startRange`
+  - : The token is a part of the start date.
+- `endRange`
+  - : The token is a part of the end date.
+- `shared`
+  - : The token is shared between the start and end; for example, if the start and end dates share the same day period, that token may get reused. All literals that are part of the range pattern itself, such as the `" – "` separator, are also marked as `shared`.
+
+If the start and end dates are equivalent at the precision of the output, then the output has the same list of tokens as calling {{jsxref("Intl/DateTimeFormat/formatToParts", "formatToParts()")}} on the start date, with all tokens marked as `source: "shared"`.
 
-### Basic formatRangeToParts usage
+## Examples
 
-This method receives two {{jsxref("Date")}}s and returns an {{jsxref("Array")}} of
-objects containing the _locale-specific_ tokens representing each part of the formatted date range.
+### Using formatRangeToParts()
 
-> [!NOTE]
-> The return values shown in your locale may differ from those listed below.
+The `formatRange()` method outputs localized, opaque strings that cannot be manipulated directly:
 
 ```js
 const date1 = new Date(Date.UTC(1906, 0, 10, 10, 0, 0)); // Wed, 10 Jan 1906 10:00:00 GMT
@@ -38,19 +55,25 @@ const fmt = new Intl.DateTimeFormat("en", {
 });
 
 console.log(fmt.formatRange(date1, date2)); // '10:00 – 11:00 AM'
+```
+
+However, in many user interfaces you may want to customize the formatting of this string, or interleave it with other texts. The `formatRangeToParts()` method produces the same information in parts:
 
-fmt.formatRangeToParts(date1, date2);
-// [
-//   { type: 'hour',      value: '10',  source: "startRange" },
-//   { type: 'literal',   value: ':',   source: "startRange" },
-//   { type: 'minute',    value: '00',  source: "startRange" },
-//   { type: 'literal',   value: ' – ', source: "shared"     },
-//   { type: 'hour',      value: '11',  source: "endRange"   },
-//   { type: 'literal',   value: ':',   source: "endRange"   },
-//   { type: 'minute',    value: '00',  source: "endRange"   },
-//   { type: 'literal',   value: ' ',   source: "shared"     },
-//   { type: 'dayPeriod', value: 'AM',  source: "shared"     }
-// ]
+```js
+console.log(fmt.formatRangeToParts(date1, date2));
+
+// return value:
+[
+  { type: "hour", value: "10", source: "startRange" },
+  { type: "literal", value: ":", source: "startRange" },
+  { type: "minute", value: "00", source: "startRange" },
+  { type: "literal", value: " – ", source: "shared" },
+  { type: "hour", value: "11", source: "endRange" },
+  { type: "literal", value: ":", source: "endRange" },
+  { type: "minute", value: "00", source: "endRange" },
+  { type: "literal", value: " ", source: "shared" },
+  { type: "dayPeriod", value: "AM", source: "shared" },
+];
 ```
 
 ## Specifications
@@ -63,5 +86,5 @@ fmt.formatRangeToParts(date1, date2);
 
 ## See also
 
-- {{jsxref("Intl/DateTimeFormat/formatRange", "Intl.DateTimeFormat.prototype.formatRange()")}}
 - {{jsxref("Intl.DateTimeFormat")}}
+- {{jsxref("Intl/DateTimeFormat/formatRange", "Intl.DateTimeFormat.prototype.formatRange()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/intl/datetimeformat/formattoparts/index.md b/files/en-us/web/javascript/reference/global_objects/intl/datetimeformat/formattoparts/index.md
index ba8c55234fee104..354d48c94821c9d 100644
--- a/files/en-us/web/javascript/reference/global_objects/intl/datetimeformat/formattoparts/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/intl/datetimeformat/formattoparts/index.md
@@ -7,7 +7,7 @@ browser-compat: javascript.builtins.Intl.DateTimeFormat.formatToParts
 
 {{JSRef}}
 
-The **`formatToParts()`** method of {{jsxref("Intl.DateTimeFormat")}} instances allows locale-aware formatting of strings produced by this `Intl.DateTimeFormat` object.
+The **`formatToParts()`** method of {{jsxref("Intl.DateTimeFormat")}} instances returns an array of objects representing each part of the formatted string that would be returned by {{jsxref("Intl/DatetimeFormat/format", "format()")}}. It is useful for building custom strings from the locale-specific tokens.
 
 {{EmbedInteractiveExample("pages/js/intl-datetimeformat-prototype-formattoparts.html", "taller")}}
 
@@ -20,65 +20,57 @@ formatToParts(date)
 ### Parameters
 
 - `date` {{optional_inline}}
-  - : The date to format.
 
-### Return value
-
-An {{jsxref("Array")}} of objects containing the formatted date in parts.
+  - : The date to format. Can be a {{jsxref("Date")}} or {{jsxref("Temporal.PlainDateTime")}} object. Additionally can be a {{jsxref("Temporal.PlainTime")}}, {{jsxref("Temporal.PlainDate")}}, {{jsxref("Temporal.PlainYearMonth")}}, or {{jsxref("Temporal.PlainMonthDay")}} object if the `DateTimeFormat` object was configured to print at least one relevant part of the date.
 
-## Description
+    > [!NOTE]
+    > A {{jsxref("Temporal.ZonedDateTime")}} object will always throw a `TypeError`; use {{jsxref("Temporal/ZonedDateTime/toLocaleString", "Temporal.ZonedDateTime.prototype.toLocaleString()")}} or convert it to a {{jsxref("Temporal.PlainDateTime")}} object instead.
 
-The `formatToParts()` method is useful for custom formatting of date
-strings. It returns an {{jsxref("Array")}} of objects containing the locale-specific
-tokens from which it possible to build custom strings while preserving the
-locale-specific parts. The structure the `formatToParts()` method returns,
-looks like this:
+    Omitting it results in formatting the current date (as returned by {{jsxref("Date.now()")}}), which could be slightly confusing, so it is advisable to always explicitly pass a date.
 
-```js
-[
-  { type: "day", value: "17" },
-  { type: "weekday", value: "Monday" },
-];
-```
+### Return value
 
-Possible types are the following:
+An {{jsxref("Array")}} of objects containing the formatted date in parts. Each object has two properties, `type` and `value`, each containing a string. The string concatenation of `value`, in the order provided, will result in the same string as {{jsxref("Intl/DateTimeFormat/format", "format()")}}. The `type` may be one of the [date-time components](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat/DateTimeFormat#date-time_component_options):
 
+- `weekday`
+  - : For example `"M"`, `"Monday"`, or `"Montag"`.
+- `era`
+  - : For example `"BC"` or `"AD"`.
+- `year`
+  - : For example `"2012"` or `"96"`.
+- `month`
+  - : For example `"12"` or `"January"`.
 - `day`
-  - : The string used for the day, for example `"17"`.
+  - : For example `"17"`.
 - `dayPeriod`
-  - : The string used for the day period, for example, `"AM"`,
-    `"PM"`, `"in the morning"`, or `"noon"`
-- `era`
-  - : The string used for the era, for example `"BC"` or `"AD"`.
-- `fractionalSecond`
-  - : The string used for the fractional seconds, for example `"0"` or `"00"` or `"000"`.
+  - : For example `"AM"`, `"PM"`, `"in the morning"`, or `"noon"`.
 - `hour`
-  - : The string used for the hour, for example `"3"` or `"03"`.
-- `literal`
-  - : The string used for separating date and time values, for example `"/"`,
-    `","`, `"o'clock"`, `"de"`, etc.
+  - : For example `"3"` or `"03"`.
 - `minute`
-  - : The string used for the minute, for example `"00"`.
-- `month`
-  - : The string used for the month, for example `"12"`.
-- `relatedYear`
-  - : The string used for the related 4-digit Gregorian year, in the event that the
-    calendar's representation would be a yearName instead of a year, for example `"2019"`.
+  - : For example `"00"`.
 - `second`
-  - : The string used for the second, for example `"07"` or `"42"`.
+  - : For example `"07"` or `"42"`.
+- `fractionalSecond`
+  - : For example `"0"`, `"00"`, or `"000"`.
 - `timeZoneName`
-  - : The string used for the name of the time zone, for example `"UTC"`. Default is the timezone of the current environment.
-- `weekday`
-  - : The string used for the weekday, for example `"M"`, `"Monday"`, or `"Montag"`.
-- `year`
-  - : The string used for the year, for example `"2012"` or `"96"`.
+  - : For example `"UTC"`, `"CET"`, or `"Central European Time"`.
+
+The `type` may also be one of the following:
+
+- `literal`
+  - : Any string that's a part of the format pattern and not influenced by the `date`; for example `"/"`, `", "`, `"o'clock"`, `"de"`, `" "`, etc.
+- `relatedYear`
+  - : A 4-digit Gregorian year, in the event that the calendar's representation would be a `yearName` instead of a year; for example `"2019"`. See [named years](#named_years) for more details.
 - `yearName`
-  - : The string used for the yearName in relevant contexts, for example `"geng-zi"`
+  - : The name given to the year, usually in calendars without the concept of continuous years; for example `"geng-zi"`.
+- `unknown`
+  - : Reserved for any token that's not recognized as any of the above; should be rarely encountered.
 
 ## Examples
 
-`DateTimeFormat` outputs localized, opaque strings that cannot be
-manipulated directly:
+### Using formatToParts()
+
+The `format()` method outputs localized, opaque strings that cannot be manipulated directly:
 
 ```js
 const date = Date.UTC(2012, 11, 17, 3, 0, 42);
@@ -100,9 +92,7 @@ formatter.format(date);
 // "Monday, 12/17/2012, 3:00:42.000 AM"
 ```
 
-However, in many User Interfaces there is a desire to customize the formatting of this
-string. The `formatToParts` method enables locale-aware formatting of strings
-produced by `DateTimeFormat` formatters by providing you the string in parts:
+However, in many user interfaces you may want to customize the formatting of this string, or interleave it with other texts. The `formatToParts()` method produces the same information in parts:
 
 ```js
 formatter.formatToParts(date);
@@ -128,12 +118,7 @@ formatter.formatToParts(date);
 ];
 ```
 
-Now the information is available separately and it can be formatted and concatenated
-again in a customized way. For example by using {{jsxref("Array.prototype.map()")}},
-[arrow functions](/en-US/docs/Web/JavaScript/Reference/Functions/Arrow_functions),
-a [switch statement](/en-US/docs/Web/JavaScript/Reference/Statements/switch),
-[template literals](/en-US/docs/Web/JavaScript/Reference/Template_literals),
-and {{jsxref("Array.prototype.join()")}}.
+Now the information is available separately and it can be formatted and concatenated again in a customized way. For example by using {{jsxref("Array.prototype.map()")}}, [arrow functions](/en-US/docs/Web/JavaScript/Reference/Functions/Arrow_functions), a [switch statement](/en-US/docs/Web/JavaScript/Reference/Statements/switch), [template literals](/en-US/docs/Web/JavaScript/Reference/Template_literals), and {{jsxref("Array.prototype.join()")}}, to insert additional markup for certain components.
 
 ```js
 const dateString = formatter
@@ -147,36 +132,20 @@ const dateString = formatter
     }
   })
   .join("");
-```
-
-This will emphasize the day period when using the `formatToParts()` method.
-
-```js
-console.log(formatter.format(date));
-// "Monday, 12/17/2012, 3:00:42.000 AM"
 
 console.log(dateString);
 // "Monday, 12/17/2012, 3:00:42.000 <em>AM</em>"
 ```
 
-### Named Years and Mixed calendars
+### Named years
 
-In some cases, calendars use named years. Chinese and Tibetan calendars, for example,
-use a 60-year [sexagenary cycle](https://en.wikipedia.org/wiki/Sexagenary_cycle) of named years.
-These years are disambiguated by relationship to
-corresponding years on the Gregorian calendar. When this is the case, the result of
-`formatToParts()` will contain an entry for `relatedYear` when a
-year would normally be present, containing the 4-digit Gregorian year, instead of an
-entry for `year`. Setting an entry in the bag for `year` (with any
-value) will yield both the and the `yearName` Gregorian
-`relatedYear`:
+Some calendars use named years; for example, the Chinese and Tibetan calendars use a 60-year [sexagenary cycle](https://en.wikipedia.org/wiki/Sexagenary_cycle) of named years. These calendars do not have a universal way to unambiguously number each year, so years are disambiguated by relationship to corresponding years on the Gregorian calendar. In this case, when the `DateTimeFormat` is configured to output the year component, a token for `relatedYear` is output instead of `year`.
 
 ```js
-const opts = { year: "numeric", month: "numeric", day: "numeric" };
-const df = new Intl.DateTimeFormat("zh-u-ca-chinese", opts);
+const df = new Intl.DateTimeFormat("zh-u-ca-chinese");
 df.formatToParts(Date.UTC(2012, 11, 17, 3, 0, 42));
 
-// return value
+// return value:
 [
   { type: "relatedYear", value: "2012" },
   { type: "literal", value: "年" },
@@ -185,53 +154,24 @@ df.formatToParts(Date.UTC(2012, 11, 17, 3, 0, 42));
 ];
 ```
 
-If the `year` option is not set in the bag (to any value), the result will
-include only the `relatedYear`:
+Sometimes, the combination of date-time component options maps to a format that also includes a `yearName`. There isn't a separate option that controls whether `yearName` is displayed or not. For example, the options below sets `month` to `"long"` and results in a `yearName` token, despite `year` still being `"numeric"`:
 
 ```js
-const df = new Intl.DateTimeFormat("zh-u-ca-chinese");
+const opts = { year: "numeric", month: "long", day: "numeric" };
+const df = new Intl.DateTimeFormat("zh-u-ca-chinese", opts);
 df.formatToParts(Date.UTC(2012, 11, 17, 3, 0, 42));
 
-// return value
+// return value:
 [
   { type: "relatedYear", value: "2012" },
+  { type: "yearName", value: "壬辰" },
   { type: "literal", value: "年" },
   { type: "month", value: "十一月" },
   { type: "day", value: "4" },
 ];
 ```
 
-In cases where the `year` would be output, `.format()` may
-commonly present these side-by-side:
-
-```js
-const df = new Intl.DateTimeFormat("zh-u-ca-chinese", { year: "numeric" });
-df.format(Date.UTC(2012, 11, 17, 3, 0, 42)); // 2012壬辰年
-```
-
-This also makes it possible to mix locale and calendar in both `format`:
-
-```js
-const df = new Intl.DateTimeFormat("en-u-ca-chinese", { year: "numeric" });
-const date = Date.UTC(2012, 11, 17, 3, 0, 42);
-df.format(date); // 2012(ren-chen)
-```
-
-And `formatToParts`:
-
-```js
-const opts = { month: "numeric", day: "numeric", year: "numeric" };
-const df = new Intl.DateTimeFormat("en-u-ca-chinese", opts);
-const date = Date.UTC(2012, 11, 17, 3);
-df.formatToParts(date);
-// [
-//   { type: 'month', value: '11' },
-//   { type: 'literal', value: '/' },
-//   { type: 'day', value: '4' },
-//   { type: 'literal', value: '/' },
-//   { type: 'relatedYear', value: '2012' }
-// ]
-```
+Because `format()` just concatenates all the `value` strings together, you will see the Gregorian year and the year name together in the output in this case.
 
 ## Specifications
 
@@ -245,6 +185,3 @@ df.formatToParts(date);
 
 - {{jsxref("Intl.DateTimeFormat")}}
 - {{jsxref("Intl/DateTimeFormat/format", "Intl.DateTimeFormat.prototype.format()")}}
-- {{jsxref("Date.prototype.toLocaleString()")}}
-- {{jsxref("Date.prototype.toLocaleDateString()")}}
-- {{jsxref("Date.prototype.toLocaleTimeString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/intl/datetimeformat/index.md b/files/en-us/web/javascript/reference/global_objects/intl/datetimeformat/index.md
index 80f972ef026ec54..97c5198f98606f7 100644
--- a/files/en-us/web/javascript/reference/global_objects/intl/datetimeformat/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/intl/datetimeformat/index.md
@@ -186,3 +186,13 @@ console.log(usedOptions.timeZone);
 
 - [Polyfill of `Intl.DateTimeFormat` in FormatJS](https://formatjs.github.io/docs/polyfills/intl-datetimeformat/)
 - {{jsxref("Intl")}}
+- {{jsxref("Date.prototype.toLocaleString()")}}
+- {{jsxref("Date.prototype.toLocaleDateString()")}}
+- {{jsxref("Date.prototype.toLocaleTimeString()")}}
+- {{jsxref("Temporal/Instant/toLocaleString", "Temporal.Instant.prototype.toLocaleString()")}}
+- {{jsxref("Temporal/PlainDate/toLocaleString", "Temporal.PlainDate.prototype.toLocaleString()")}}
+- {{jsxref("Temporal/PlainDateTime/toLocaleString", "Temporal.PlainDateTime.prototype.toLocaleString()")}}
+- {{jsxref("Temporal/PlainTime/toLocaleString", "Temporal.PlainTime.prototype.toLocaleString()")}}
+- {{jsxref("Temporal/PlainYearMonth/toLocaleString", "Temporal.PlainYearMonth.prototype.toLocaleString()")}}
+- {{jsxref("Temporal/PlainMonthDay/toLocaleString", "Temporal.PlainMonthDay.prototype.toLocaleString()")}}
+- {{jsxref("Temporal/ZonedDateTime/toLocaleString", "Temporal.ZonedDateTime.prototype.toLocaleString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/intl/datetimeformat/resolvedoptions/index.md b/files/en-us/web/javascript/reference/global_objects/intl/datetimeformat/resolvedoptions/index.md
index e78b7f64ce155a0..e5cc64d179840f9 100644
--- a/files/en-us/web/javascript/reference/global_objects/intl/datetimeformat/resolvedoptions/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/intl/datetimeformat/resolvedoptions/index.md
@@ -28,15 +28,15 @@ A new object with properties reflecting the options computed during the initiali
 - `locale`
   - : The BCP 47 language tag for the locale actually used, determined by the [locale negotiation](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl#locale_identification_and_negotiation) process. Only the `ca`, `hc`, and `nu` Unicode extension keys, if requested, may be included in the output.
 - `calendar`
-  - : The value provided for this property in the `options` argument, or using the Unicode extension key `"ca"`, with default filled in as needed. It is a supported [calendar type](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/Locale/getCalendars#supported_calendar_types) for this locale. The default is locale dependent.
+  - : The value provided for this property in the `options` argument, or using the Unicode extension key `"ca"`, with default filled in as needed. It is a supported [calendar type](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/supportedValuesOf#supported_calendar_types) for this locale. The default is locale dependent.
 - `numberingSystem`
-  - : The value provided for this property in the `options` argument, or using the Unicode extension key `"nu"`, with default filled in as needed. It is a supported [numbering system](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/Locale/getNumberingSystems#supported_numbering_system_types) for this locale. The default is locale dependent.
+  - : The value provided for this property in the `options` argument, or using the Unicode extension key `"nu"`, with default filled in as needed. It is a supported [numbering system](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/supportedValuesOf#supported_numbering_system_types) for this locale. The default is locale dependent.
 - `timeZone`
 
-  - : The value provided for this property in the `options` argument, with default filled in as needed. It is a canonicalized [IANA time zone name](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/Locale/getTimeZones). The default is the runtime's default time zone.
+  - : The value provided for this property in the `options` argument, with default filled in as needed. It is an [IANA time zone name](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#time_zones_and_offsets). The default is the runtime's default time zone.
 
     > [!NOTE]
-    > While the IANA database changes from time to time, the Unicode CLDR database (which browsers use) keeps old time zone names for stability purposes. All browsers canonicalize time zone names, but in different directions. For example, `new Intl.DateTimeFormat("en-US", { timeZone: "Europe/Kiev" }).resolvedOptions().timeZone` and `new Intl.DateTimeFormat("en-US", { timeZone: "Europe/Kyiv" }).resolvedOptions().timeZone` will return the same string in the same browser, but maybe different strings in different browsers. See {{jsxref("Intl/Locale/getTimeZones", "Intl.Locale.prototype.getTimeZones")}} for more information.
+    > The standardization of `Temporal` requires browsers to use the same identifier as originally specified, without canonicalization to a different alias. See [time zones and offsets](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#time_zones_and_offsets) for more information.
 
 - `hourCycle` {{optional_inline}}
   - : The value provided for this property in the `options` argument, or using the Unicode extension key `"hc"`, with default filled in as needed. If `hour12` was provided in the `options`, then that overrides other `hourCycle` settings. It is only present if the resolved options also include `hour` or `timeStyle`. It is either `"h11"`, `"h12"`, `"h23"`, or `"h24"`. The default is locale dependent, although `"h24"` is never a default.
diff --git a/files/en-us/web/javascript/reference/global_objects/intl/durationformat/durationformat/index.md b/files/en-us/web/javascript/reference/global_objects/intl/durationformat/durationformat/index.md
index a99fe8f9a8c733a..345c444e9108d5f 100644
--- a/files/en-us/web/javascript/reference/global_objects/intl/durationformat/durationformat/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/intl/durationformat/durationformat/index.md
@@ -39,9 +39,9 @@ new Intl.DurationFormat(locales, options)
     - `localeMatcher`
       - : The locale matching algorithm to use. Possible values are `"lookup"` and `"best fit"`; the default is `"best fit"`. For information about this option, see [Locale identification and negotiation](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl#locale_identification_and_negotiation).
     - `numberingSystem`
-      - : The numbering system to use for number formatting, such as `"arab"`, `"hans"`, `"mathsans"`, and so on. For a list of supported numbering system types, see [`Intl.Locale.prototype.getNumberingSystems()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/Locale/getNumberingSystems#supported_numbering_system_types). This option can also be set through the `nu` Unicode extension key; if both are provided, this `options` property takes precedence.
+      - : The numbering system to use for number formatting, such as `"arab"`, `"hans"`, `"mathsans"`, and so on. For a list of supported numbering system types, see [`Intl.supportedValuesOf()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/supportedValuesOf#supported_numbering_system_types). This option can also be set through the `nu` Unicode extension key; if both are provided, this `options` property takes precedence.
     - `style`
-      - : The style of the formatted duration. Possible values are:
+      - : The style of the formatted duration. This value is used as the default for all other unit options, and also corresponds to the `style` option of {{jsxref("Intl/ListFormat/ListFormat", "Intl.ListFormat()")}} when concatenating the list of duration units. Possible values are:
         - `"long"`
           - : E.g., 1 hour and 50 minutes
         - `"short"` (default)
diff --git a/files/en-us/web/javascript/reference/global_objects/intl/durationformat/format/index.md b/files/en-us/web/javascript/reference/global_objects/intl/durationformat/format/index.md
index 703694c7d55bcbd..8ee2bda11222262 100644
--- a/files/en-us/web/javascript/reference/global_objects/intl/durationformat/format/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/intl/durationformat/format/index.md
@@ -18,7 +18,7 @@ format(duration)
 ### Parameters
 
 - `duration`
-  - : The duration object to be formatted. It should include some or all of the following properties: `months`, `weeks`, `days`, `hours`, `minutes`, `seconds`, `milliseconds`, `microseconds`, `nanoseconds`.
+  - : The duration object to be formatted. It should include some or all of the following properties: `years`, `months`, `weeks`, `days`, `hours`, `minutes`, `seconds`, `milliseconds`, `microseconds`, `nanoseconds`. Can be a {{jsxref("Temporal.Duration")}} object.
 
 ### Return value
 
@@ -128,5 +128,4 @@ new Intl.DurationFormat("en", { style: "digital", fractionalDigits: 3 }).format(
 ## See also
 
 - {{jsxref("Intl.DurationFormat")}}
-- {{jsxref("Intl.supportedValuesOf()")}}
-- {{jsxref("Intl")}}
+- {{jsxref("Temporal.Duration")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/intl/durationformat/formattoparts/index.md b/files/en-us/web/javascript/reference/global_objects/intl/durationformat/formattoparts/index.md
index b6c89eafff3a7dd..635ef7443a4b2af 100644
--- a/files/en-us/web/javascript/reference/global_objects/intl/durationformat/formattoparts/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/intl/durationformat/formattoparts/index.md
@@ -7,7 +7,7 @@ browser-compat: javascript.builtins.Intl.DurationFormat.formatToParts
 
 {{JSRef}}
 
-The **`formatToParts()`** method of {{jsxref("Intl.DurationFormat")}} instances allows locale-aware formatting of strings produced by {{jsxref("Intl.DurationFormat")}} formatters.
+The **`formatToParts()`** method of {{jsxref("Intl.DurationFormat")}} instances returns an array of objects representing each part of the formatted string that would be returned by {{jsxref("Intl/DurationFormat/format", "format()")}}. It is useful for building custom strings from the locale-specific tokens.
 
 ## Syntax
 
@@ -18,27 +18,11 @@ formatToParts(duration)
 ### Parameters
 
 - `duration` {{optional_inline}}
-  - : The duration object to be formatted. It should include some or all of the following properties: `"months"`, `"weeks"`, `"days"`, `"hours"`, `"minutes"`, `"seconds"`, `"milliseconds"`, `"microseconds"`, `"nanoseconds"`.
+  - : The duration object to be formatted. It should include some or all of the following properties: `years`, `months`, `weeks`, `days`, `hours`, `minutes`, `seconds`, `milliseconds`, `microseconds`, `nanoseconds`. Can be a {{jsxref("Temporal.Duration")}} object.
 
 ### Return value
 
-An {{jsxref("Array")}} of objects containing the formatted duration in parts.
-
-## Description
-
-The `formatToParts()` method is useful for custom formatting of duration objects. It returns an {{jsxref("Array")}} of objects containing the locale-specific tokens from which it possible to build custom strings while preserving the locale-specific parts. The structure the `formatToParts()` method returns, looks like this:
-
-```js
-[
-  { type: "integer", value: "7", unit: "hour" },
-  { type: "literal", value: " ", unit: "hour" },
-  { type: "unit", value: "hr", unit: "hour" },
-  { type: "literal", value: ", " },
-  { type: "integer", value: "8", unit: "minute" },
-  { type: "literal", value: " ", unit: "minute" },
-  { type: "unit", value: "min", unit: "minute" },
-];
-```
+An {{jsxref("Array")}} of objects containing the formatted duration in parts. Each object has two or three properties, `type`, `value`, and optionally `unit`, each containing a string. The string concatenation of `value`, in the order provided, will result in the same string as {{jsxref("Intl/DurationFormat/format", "format()")}}. The parts can be thought of as directly obtained from calling {{jsxref("Intl/NumberFormat/formatToParts", "Intl.NumberFormat.prototype.formatToParts()")}} with the numeric value and their respective units. All tokens that are produced by the `NumberFormat` have an additional `unit` property, which is the singular form of the input `unit`; this is for programmatic usage and is not localized. The localized unit is output as a separate `unit` token as part of the `NumberFormat` result. The parts from each duration unit are concatenated together in the same fashion as calling {{jsxref("Intl/ListFormat/formatToParts", "Intl.ListFormat.prototype.formatToParts()")}} with `{ type: "unit" }`, so additional literal tokens are inserted.
 
 ## Examples
 
@@ -77,7 +61,7 @@ new Intl.DurationFormat("en", { style: "long" }).formatToParts(duration);
   { type: "integer", value: "456", unit: "microsecond" },
   { type: "literal", value: " ", unit: "microsecond" },
   { type: "unit", value: "microseconds", unit: "microsecond" },
-  { type: "literal", value: " and " },
+  { type: "literal", value: ", " },
   { type: "integer", value: "789", unit: "nanosecond" },
   { type: "literal", value: " ", unit: "nanosecond" },
   { type: "unit", value: "nanoseconds", unit: "nanosecond" },
@@ -95,5 +79,5 @@ new Intl.DurationFormat("en", { style: "long" }).formatToParts(duration);
 ## See also
 
 - {{jsxref("Intl.DurationFormat")}}
-- {{jsxref("Intl.supportedValuesOf()")}}
-- {{jsxref("Intl")}}
+- {{jsxref("Intl/DurationFormat/format", "Intl.DurationFormat.prototype.format()")}}
+- {{jsxref("Temporal.Duration")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/intl/durationformat/index.md b/files/en-us/web/javascript/reference/global_objects/intl/durationformat/index.md
index 6c9a0ac3b31e913..f0c426a3bc1699d 100644
--- a/files/en-us/web/javascript/reference/global_objects/intl/durationformat/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/intl/durationformat/index.md
@@ -75,3 +75,4 @@ new Intl.DurationFormat("pt", { style: "narrow" }).format(duration);
 
 - [Polyfill of `Intl.DurationFormat` in FormatJS](https://formatjs.github.io/docs/polyfills/intl-durationformat/)
 - {{jsxref("Intl")}}
+- {{jsxref("Temporal/Duration/toLocaleString", "Temporal.Duration.prototype.toLocaleString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/intl/durationformat/resolvedoptions/index.md b/files/en-us/web/javascript/reference/global_objects/intl/durationformat/resolvedoptions/index.md
index 11fe6e2f804d0a5..6ce98ef904b4f92 100644
--- a/files/en-us/web/javascript/reference/global_objects/intl/durationformat/resolvedoptions/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/intl/durationformat/resolvedoptions/index.md
@@ -26,7 +26,7 @@ A new object with properties reflecting the options computed during the initiali
 - `locale`
   - : The BCP 47 language tag for the locale actually used, determined by the [locale negotiation](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl#locale_identification_and_negotiation) process. Only the `nu` Unicode extension key, if requested, may be included in the output.
 - `numberingSystem`
-  - : The value provided for this property in the `options` argument, or using the Unicode extension key `"nu"`, with default filled in as needed. It is a supported [numbering system](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/Locale/getNumberingSystems#supported_numbering_system_types) for this locale. The default is locale dependent.
+  - : The value provided for this property in the `options` argument, or using the Unicode extension key `"nu"`, with default filled in as needed. It is a supported [numbering system](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/supportedValuesOf#supported_numbering_system_types) for this locale. The default is locale dependent.
 - `style`
   - : The value provided for this property in the `options` argument, with default filled in as needed. It is either `"long"`, `"short"`, `"narrow"`, or `"digital"`. The default is `"short"`.
 - `years`, `yearsDisplay`, `months`, `monthsDisplay`, `weeks`, `weeksDisplay`, `days`, `daysDisplay`, `hours`, `hoursDisplay`, `minutes`, `minutesDisplay`, `seconds`, `secondsDisplay`, `milliseconds`, `millisecondsDisplay`, `nanoseconds`, `nanosecondsDisplay`
diff --git a/files/en-us/web/javascript/reference/global_objects/intl/index.md b/files/en-us/web/javascript/reference/global_objects/intl/index.md
index c7647ce3fdbebcc..711bfb82ceffff2 100644
--- a/files/en-us/web/javascript/reference/global_objects/intl/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/intl/index.md
@@ -151,11 +151,6 @@ const formattedCount = new Intl.NumberFormat(navigator.languages).format(count);
 
 ## See also
 
-- {{jsxref("String.prototype.localeCompare()")}}
-- {{jsxref("Number.prototype.toLocaleString()")}}
-- {{jsxref("Date.prototype.toLocaleString()")}}
-- {{jsxref("Date.prototype.toLocaleDateString()")}}
-- {{jsxref("Date.prototype.toLocaleTimeString()")}}
 - {{domxref("Keyboard.getLayoutMap()")}}
 - {{domxref("navigator.language")}}
 - {{domxref("navigator.languages")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/intl/listformat/format/index.md b/files/en-us/web/javascript/reference/global_objects/intl/listformat/format/index.md
index c8a9261ff1c3424..404604815e04dfb 100644
--- a/files/en-us/web/javascript/reference/global_objects/intl/listformat/format/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/intl/listformat/format/index.md
@@ -15,14 +15,13 @@ language-specific representation of the list.
 ## Syntax
 
 ```js-nolint
-format()
 format(list)
 ```
 
 ### Parameters
 
 - `list`
-  - : An iterable object, such as an Array.
+  - : An iterable object, such as an Array, containing strings. Omitting it results in formatting the empty array, which could be slightly confusing, so it is advisable to always explicitly pass a list.
 
 ### Return value
 
@@ -31,14 +30,6 @@ A language-specific formatted string representing the elements of the list.
 > [!NOTE]
 > Most of the time, the formatting returned by `format()` is consistent. However, the output may vary between implementations, even within the same locale — output variations are by design and allowed by the specification. It may also not be what you expect. For example, the string may use non-breaking spaces or be surrounded by bidirectional control characters. You should not compare the results of `format()` to hardcoded constants.
 
-## Description
-
-The **`format()`** method returns a string that has been
-formatted based on parameters provided in the `Intl.ListFormat` object. The
-`locales` and `options` parameters customize the behavior of
-`format()` and let applications specify the language conventions that
-should be used to format the list.
-
 ## Examples
 
 ### Using format
diff --git a/files/en-us/web/javascript/reference/global_objects/intl/listformat/formattoparts/index.md b/files/en-us/web/javascript/reference/global_objects/intl/listformat/formattoparts/index.md
index e536b44bf4b8ac0..47dc10926ae06d1 100644
--- a/files/en-us/web/javascript/reference/global_objects/intl/listformat/formattoparts/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/intl/listformat/formattoparts/index.md
@@ -7,9 +7,7 @@ browser-compat: javascript.builtins.Intl.ListFormat.formatToParts
 
 {{JSRef}}
 
-The **`formatToParts()`** method of {{jsxref("Intl.ListFormat")}} instances
-returns an {{jsxref("Array")}} of objects representing the different components that
-can be used to format a list of values in a locale-aware fashion.
+The **`formatToParts()`** method of {{jsxref("Intl.ListFormat")}} instances returns an array of objects representing each part of the formatted string that would be returned by {{jsxref("Intl/ListFormat/format", "format()")}}. It is useful for building custom strings from the locale-specific tokens.
 
 {{EmbedInteractiveExample("pages/js/intl-listformat-prototype-formattoparts.html", "taller")}}
 
@@ -22,31 +20,20 @@ formatToParts(list)
 ### Parameters
 
 - `list`
-  - : An iterable object, such as an {{jsxref("Array")}}, to be formatted according to a locale.
+  - : An iterable object, such as an Array, containing strings. Omitting it results in formatting the empty array, which could be slightly confusing, so it is advisable to always explicitly pass a list.
 
 ### Return value
 
-An {{jsxref("Array")}} of components which contains the formatted parts from the list.
+An {{jsxref("Array")}} of objects containing the formatted list in parts. Each object has two properties, `type` and `value`, each containing a string. The string concatenation of `value`, in the order provided, will result in the same string as {{jsxref("Intl/ListFormat/format", "format()")}}. The `type` may be one of the following:
 
-## Description
-
-Whereas {{jsxref("Intl/ListFormat/format", "Intl.ListFormat.prototype.format()")}} returns a string being the formatted version
-of the list (according to the given locale and style options),
-`formatToParts()` returns an array of the different components of the
-formatted string.
-
-Each element of the resulting array has two properties: `type` and
-`value`. The `type` property may be either
-`"element"`, which refers to a value from the list, or
-`"literal"` which refers to a linguistic construct. The `value`
-property gives the content, as a string, of the token.
-
-The locale and style options used for formatting are given when constructing the
-{{jsxref("Intl.ListFormat")}} instance.
+- `literal`
+  - : Any string that's a part of the format pattern; for example `", "`, `", and"`, etc.
+- `element`
+  - : An element of the list, exactly as provided.
 
 ## Examples
 
-### Using formatToParts
+### Using formatToParts()
 
 ```js
 const fruits = ["Apple", "Orange", "Pineapple"];
@@ -77,6 +64,3 @@ console.table(myListFormat.formatToParts(fruits));
 
 - {{jsxref("Intl.ListFormat")}}
 - {{jsxref("Intl/ListFormat/format", "Intl.ListFormat.prototype.format()")}}
-- {{jsxref("Intl/RelativeTimeFormat/formatToParts", "Intl.RelativeTimeFormat.prototype.formatToParts()")}}
-- {{jsxref("Intl/NumberFormat/formatToParts", "Intl.NumberFormat.prototype.formatToParts()")}}
-- {{jsxref("Intl/DateTimeFormat/formatToParts", "Intl.DateTimeFormat.prototype.formatToParts()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/intl/locale/calendar/index.md b/files/en-us/web/javascript/reference/global_objects/intl/locale/calendar/index.md
index 6a879fc0936318e..bf441cef9e7dce2 100644
--- a/files/en-us/web/javascript/reference/global_objects/intl/locale/calendar/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/intl/locale/calendar/index.md
@@ -13,7 +13,7 @@ The **`calendar`** accessor property of {{jsxref("Intl.Locale")}} instances retu
 
 While most of the world uses the Gregorian calendar, there are several regional calendar eras used around the world. The `calendar` property's value is set at construction time, either through the `ca` key of the locale identifier or through the `calendar` option of the {{jsxref("Intl/Locale/Locale", "Intl.Locale()")}} constructor. The latter takes priority if they are both present; and if neither is present, the property has value `undefined`.
 
-For a list of supported calendar types, see [`Intl.Locale.prototype.getCalendars()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/Locale/getCalendars#supported_calendar_types).
+For a list of supported calendar types, see [`Intl.supportedValuesOf()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/supportedValuesOf#supported_calendar_types).
 
 The set accessor of `calendar` is `undefined`. You cannot change this property directly.
 
diff --git a/files/en-us/web/javascript/reference/global_objects/intl/locale/collation/index.md b/files/en-us/web/javascript/reference/global_objects/intl/locale/collation/index.md
index 07c0e6a7af5a10f..f829c48dda09998 100644
--- a/files/en-us/web/javascript/reference/global_objects/intl/locale/collation/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/intl/locale/collation/index.md
@@ -13,7 +13,7 @@ The **`collation`** accessor property of {{jsxref("Intl.Locale")}} instances ret
 
 Collation is the process of ordering strings of characters. It is used whenever strings must be sorted and placed into a certain order, from search query results to ordering records in a database. While the idea of placing strings in order might seem trivial, the idea of order can vary from region to region and language to language. The `collation` property's value is set at construction time, either through the `co` key of the locale identifier or through the `collation` option of the {{jsxref("Intl/Locale/Locale", "Intl.Locale()")}} constructor. The latter takes priority if they are both present; and if neither is present, the property has value `undefined`.
 
-For a list of supported collation types, see [`Intl.Locale.prototype.getCollations()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/Locale/getCollations#supported_collation_types).
+For a list of supported collation types, see [`Intl.supportedValuesOf()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/supportedValuesOf#supported_collation_types).
 
 The set accessor of `collation` is `undefined`. You cannot change this property directly.
 
diff --git a/files/en-us/web/javascript/reference/global_objects/intl/locale/getcalendars/index.md b/files/en-us/web/javascript/reference/global_objects/intl/locale/getcalendars/index.md
index ae017560db3f82c..46808728f39a454 100644
--- a/files/en-us/web/javascript/reference/global_objects/intl/locale/getcalendars/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/intl/locale/getcalendars/index.md
@@ -26,50 +26,7 @@ None.
 
 An array of strings representing all calendars commonly used for the `Locale`, sorted in descending preference. If the `Locale` already has a [`calendar`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/Locale/calendar), then the returned array contains that single value.
 
-Below is a list of the supported calendar era types.
-
-### Supported calendar types
-
-- `buddhist`
-  - : Thai Buddhist calendar
-- `chinese`
-  - : Traditional Chinese calendar
-- `coptic`
-  - : Coptic calendar
-- `dangi`
-  - : Traditional Korean calendar
-- `ethioaa`
-  - : Ethiopic calendar, Amete Alem (epoch approx. 5493 B.C.E)
-- `ethiopic`
-  - : Ethiopic calendar, Amete Mihret (epoch approx, 8 C.E.)
-- `gregory`
-  - : Gregorian calendar
-- `hebrew`
-  - : Traditional Hebrew calendar
-- `indian`
-  - : Indian calendar
-- `islamic`
-  - : Islamic calendar
-- `islamic-umalqura`
-  - : Islamic calendar, Umm al-Qura
-- `islamic-tbla`
-  - : Islamic calendar, tabular (intercalary years [2,5,7,10,13,16,18,21,24,26,29] - astronomical epoch)
-- `islamic-civil`
-  - : Islamic calendar, tabular (intercalary years [2,5,7,10,13,16,18,21,24,26,29] - civil epoch)
-- `islamic-rgsa`
-  - : Islamic calendar, Saudi Arabia sighting
-- `iso8601`
-  - : ISO calendar (Gregorian calendar using the ISO 8601 calendar week rules)
-- `japanese`
-  - : Japanese Imperial calendar
-- `persian`
-  - : Persian calendar
-- `roc`
-  - : Civil (algorithmic) Arabic calendar
-- `islamicc`
-  - : Civil (algorithmic) Arabic calendar
-    > [!WARNING]
-    > The `islamicc` calendar key has been deprecated. Please use `islamic-civil`.
+For a list of supported calendar types, see [`Intl.supportedValuesOf()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/supportedValuesOf#supported_calendar_types).
 
 ## Examples
 
diff --git a/files/en-us/web/javascript/reference/global_objects/intl/locale/getcollations/index.md b/files/en-us/web/javascript/reference/global_objects/intl/locale/getcollations/index.md
index 5936925b98d33b9..d6df20be6813464 100644
--- a/files/en-us/web/javascript/reference/global_objects/intl/locale/getcollations/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/intl/locale/getcollations/index.md
@@ -26,66 +26,7 @@ None.
 
 An array of strings representing all collation types commonly used for the `Locale`, sorted in alphabetical order, with the `standard` and `search` values always excluded. If the `Locale` already has a [`collation`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/Locale/collation), then the returned array contains that single value.
 
-Below is a list of the supported collation types, adapted from the [Unicode collation specification](https://github.com/unicode-org/cldr/blob/2dd06669d833823e26872f249aa304bc9d9d2a90/common/bcp47/collation.xml).
-
-### Supported collation types
-
-- `big5han`
-  - : Pinyin ordering for Latin, big5 charset ordering for CJK characters (for Chinese)
-    > [!WARNING]
-    > The `big5han` collation type is deprecated, not available in Firefox, Chrome or Edge.
-- `compat`
-  - : A previous version of the ordering, for compatibility (for Arabic)
-- `dict`
-  - : Dictionary style ordering (for Sinhala)
-- `direct`
-  - : Binary code point order
-    > [!WARNING]
-    > The `direct` collation type has been deprecated. Do not use.
-- `ducet`
-  - : The default Unicode collation element table order
-    > [!WARNING]
-    > The `ducet` collation type is not available to the Web. Use the `und` locale without a collation type specifier instead. `und` is the collation that is the closest to `ducet`.
-- `emoji`
-  - : Recommended ordering for emoji characters (for the `und` locale)
-- `eor`
-  - : European ordering rules (for the `und` locale)
-- `gb2312`
-  - : Pinyin ordering for Latin, gb2312han charset ordering for CJK characters (for Chinese)
-    > [!WARNING]
-    > The `gb2312` collation type is deprecated, not available in Firefox, Chrome or Edge.
-- `phonebk`
-  - : Phonebook style ordering (for German)
-- `phonetic`
-  - : Phonetic ordering (sorting based on pronunciation; for Lingala)
-- `pinyin`
-  - : Pinyin ordering for Latin and for CJK characters (for Chinese)
-- `reformed`
-  - : Reformed ordering (formerly for Swedish)
-    > [!WARNING]
-    > Do not use explicitly. This is the old name for the default ordering for Swedish [whose collation naming used to differ from other languages](https://unicode-org.atlassian.net/browse/CLDR-15603). Since this was the default, request `sv` instead of requesting `sv-u-co-reformed`.
-- `search`
-  - : Special collation type for string search
-    > [!WARNING]
-    > Do not use as a collation type, since in [`Intl.Collator`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/Collator), this collation is activated via the `"search"` value for the `usage` option. There is currently no API for substring search, so this is currently only good for filtering a list of strings by trying a full-string match of the key against each list item.
-- `searchjl`
-  - : Special collation type for Korean initial consonant search
-    > [!WARNING]
-    > This collation is not for sorting, even though it is made available through [`Intl.Collator`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/Collator) instantiated with usage `"sort"` as opposed to usage `"search"`.
-- `standard`
-  - : Default ordering for each language, except Chinese (and, previously, Swedish)
-    > [!WARNING]
-    > Do not use explicitly. In general, it's unnecessary to specify this explicitly and specifying this for Swedish is problematic due to the different meaning for Swedish in the past.
-- `stroke`
-  - : Pinyin ordering for Latin, stroke order for CJK characters (for Chinese)
-- `trad`
-  - : Traditional style ordering (such as in Spanish)
-- `unihan`
-  - : Radical-stroke ordering for Han characters (for Chinese, Japanese, and Korean). Pinyin ordering for Latin in the case of Chinese.
-    > [!NOTE]
-    > The `unihan` collation type is not available in Chrome or Edge.
-- `zhuyin`
-  - : Pinyin ordering for Latin, zhuyin order for Bopomofo and CJK characters (for Chinese)
+For a list of supported collation types, see [`Intl.supportedValuesOf()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/supportedValuesOf#supported_collation_types).
 
 ## Examples
 
diff --git a/files/en-us/web/javascript/reference/global_objects/intl/locale/getnumberingsystems/index.md b/files/en-us/web/javascript/reference/global_objects/intl/locale/getnumberingsystems/index.md
index a9c1ddbe31fdcc3..65ba6a701f0926c 100644
--- a/files/en-us/web/javascript/reference/global_objects/intl/locale/getnumberingsystems/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/intl/locale/getnumberingsystems/index.md
@@ -26,98 +26,7 @@ None.
 
 An array of strings representing all numbering systems commonly used for the `Locale`, sorted in descending preference. If the `Locale` already has a [`numberingSystem`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/Locale/numberingSystem), then the returned array contains that single value.
 
-A table of the standard Unicode numeral systems can be seen below.
-
-### Supported numbering system types
-
-| Value    | Description                                                                |
-| -------- | -------------------------------------------------------------------------- |
-| adlm     | Adlam digits                                                               |
-| ahom     | Ahom digits                                                                |
-| arab     | Arabic-Indic digits                                                        |
-| arabext  | Extended Arabic-Indic digits                                               |
-| armn     | Armenian upper case numerals — algorithmic                                 |
-| armnlow  | Armenian lower case numerals — algorithmic                                 |
-| bali     | Balinese digits                                                            |
-| beng     | Bengali digits                                                             |
-| bhks     | Bhaiksuki digits                                                           |
-| brah     | Brahmi digits                                                              |
-| cakm     | Chakma digits                                                              |
-| cham     | Cham digits                                                                |
-| cyrl     | Cyrillic numerals — algorithmic                                            |
-| deva     | Devanagari digits                                                          |
-| ethi     | Ethiopic numerals — algorithmic                                            |
-| finance  | Financial numerals — may be algorithmic                                    |
-| fullwide | Full width digits                                                          |
-| geor     | Georgian numerals — algorithmic                                            |
-| gong     | Gunjala Gondi digits                                                       |
-| gonm     | Masaram Gondi digits                                                       |
-| grek     | Greek upper case numerals — algorithmic                                    |
-| greklow  | Greek lower case numerals — algorithmic                                    |
-| gujr     | Gujarati digits                                                            |
-| guru     | Gurmukhi digits                                                            |
-| hanidays | Han-character day-of-month numbering for lunar/other traditional calendars |
-| hanidec  | Positional decimal system using Chinese number ideographs as digits        |
-| hans     | Simplified Chinese numerals — algorithmic                                  |
-| hansfin  | Simplified Chinese financial numerals — algorithmic                        |
-| hant     | Traditional Chinese numerals — algorithmic                                 |
-| hantfin  | Traditional Chinese financial numerals — algorithmic                       |
-| hebr     | Hebrew numerals — algorithmic                                              |
-| hmng     | Pahawh Hmong digits                                                        |
-| hmnp     | Nyiakeng Puachue Hmong digits                                              |
-| java     | Javanese digits                                                            |
-| jpan     | Japanese numerals — algorithmic                                            |
-| jpanfin  | Japanese financial numerals — algorithmic                                  |
-| jpanyear | Japanese first-year Gannen numbering for Japanese calendar                 |
-| kali     | Kayah Li digits                                                            |
-| khmr     | Khmer digits                                                               |
-| knda     | Kannada digits                                                             |
-| lana     | Tai Tham Hora (secular) digits                                             |
-| lanatham | Tai Tham (ecclesiastical) digits                                           |
-| laoo     | Lao digits                                                                 |
-| latn     | Latin digits                                                               |
-| lepc     | Lepcha digits                                                              |
-| limb     | Limbu digits                                                               |
-| mathbold | Mathematical bold digits                                                   |
-| mathdbl  | Mathematical double-struck digits                                          |
-| mathmono | Mathematical monospace digits                                              |
-| mathsanb | Mathematical sans-serif bold digits                                        |
-| mathsans | Mathematical sans-serif digits                                             |
-| mlym     | Malayalam digits                                                           |
-| modi     | Modi digits                                                                |
-| mong     | Mongolian digits                                                           |
-| mroo     | Mro digits                                                                 |
-| mtei     | Meetei Mayek digits                                                        |
-| mymr     | Myanmar digits                                                             |
-| mymrshan | Myanmar Shan digits                                                        |
-| mymrtlng | Myanmar Tai Laing digits                                                   |
-| native   | Native digits                                                              |
-| newa     | Newa digits                                                                |
-| nkoo     | N'Ko digits                                                                |
-| olck     | Ol Chiki digits                                                            |
-| orya     | Oriya digits                                                               |
-| osma     | Osmanya digits                                                             |
-| rohg     | Hanifi Rohingya digits                                                     |
-| roman    | Roman upper case numerals — algorithmic                                    |
-| romanlow | Roman lowercase numerals — algorithmic                                     |
-| saur     | Saurashtra digits                                                          |
-| shrd     | Sharada digits                                                             |
-| sind     | Khudawadi digits                                                           |
-| sinh     | Sinhala Lith digits                                                        |
-| sora     | Sora_Sompeng digits                                                        |
-| sund     | Sundanese digits                                                           |
-| takr     | Takri digits                                                               |
-| talu     | New Tai Lue digits                                                         |
-| taml     | Tamil numerals — algorithmic                                               |
-| tamldec  | Modern Tamil decimal digits                                                |
-| telu     | Telugu digits                                                              |
-| thai     | Thai digits                                                                |
-| tirh     | Tirhuta digits                                                             |
-| tibt     | Tibetan digits                                                             |
-| traditio | Traditional numerals — may be algorithmic                                  |
-| vaii     | Vai digits                                                                 |
-| wara     | Warang Citi digits                                                         |
-| wcho     | Wancho digits                                                              |
+For a list of supported numbering system types, see [`Intl.supportedValuesOf()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/supportedValuesOf#supported_numbering_system_types).
 
 ## Examples
 
diff --git a/files/en-us/web/javascript/reference/global_objects/intl/locale/gettimezones/index.md b/files/en-us/web/javascript/reference/global_objects/intl/locale/gettimezones/index.md
index 9fb96f25a7d5de4..cf4bc871bf88bbb 100644
--- a/files/en-us/web/javascript/reference/global_objects/intl/locale/gettimezones/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/intl/locale/gettimezones/index.md
@@ -24,18 +24,10 @@ None.
 
 ### Return value
 
-An array of strings representing supported time zones for the associated `Locale`, where each value is an [IANA time zone canonical name](https://en.wikipedia.org/wiki/Daylight_saving_time#IANA_time_zone_database), sorted in alphabetical order. If the locale identifier does not contain a region subtag, the returned value is `undefined`.
+An array of strings representing supported time zones for the associated `Locale`, where each value is an [IANA time zone canonical name](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#time_zones_and_offsets), sorted in alphabetical order. If the locale identifier does not contain a region subtag, the returned value is `undefined`.
 
-Note that while the IANA database changes from time to time, [the Unicode CLDR database (which browsers use) keeps old time zone names for stability purposes](https://unicode.org/reports/tr35/#Time_Zone_Identifiers). For example, here are a few notable name changes:
-
-| Current IANA name                | CLDR database          |
-| -------------------------------- | ---------------------- |
-| `America/Argentina/Buenos_Aires` | `America/Buenos_Aires` |
-| `Asia/Kolkata`                   | `Asia/Calcutta`        |
-| `Asia/Ho_Chi_Minh`               | `Asia/Saigon`          |
-| `Europe/Kyiv`                    | `Europe/Kiev`          |
-
-Some browsers (Firefox) override these legacy names, while others don't (Safari and Chrome). For more information, check the [CLDR database](https://github.com/unicode-org/cldr-json/blob/main/cldr-json/cldr-bcp47/bcp47/timezone.json). (IANA names are marked with `"_iana"`, if different.) There is [an effort in TC39 to properly handle these canonical identifiers](https://github.com/tc39/proposal-canonical-tz), which also contains links to related CLDR issues.
+> [!NOTE]
+> The standardization of `Temporal` requires browsers to always return the primary identifier in the IANA database, which may change over time. See [time zones and offsets](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#time_zones_and_offsets) for more information.
 
 ## Examples
 
diff --git a/files/en-us/web/javascript/reference/global_objects/intl/locale/locale/index.md b/files/en-us/web/javascript/reference/global_objects/intl/locale/locale/index.md
index 3a188385a995809..6b358272a601cca 100644
--- a/files/en-us/web/javascript/reference/global_objects/intl/locale/locale/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/intl/locale/locale/index.md
@@ -33,11 +33,11 @@ new Intl.Locale(tag, options)
     - `region`
       - : The region. Any syntactically valid string following the [`unicode_region_subtag`](https://unicode.org/reports/tr35/#unicode_region_subtag) grammar (either 2 letters or 3 digits) is accepted, but the implementation only recognizes certain kinds.
     - `calendar`
-      - : The calendar. Any syntactically valid string following the [`type`](https://unicode.org/reports/tr35/#Unicode_locale_identifier) grammar (one or more segments of 3–8 alphanumerals, joined by hyphens) is accepted, but the implementation only recognizes certain kinds, which are listed in [`Intl.Locale.prototype.getCalendars`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/Locale/getCalendars#supported_calendar_types).
+      - : The calendar. Any syntactically valid string following the [`type`](https://unicode.org/reports/tr35/#Unicode_locale_identifier) grammar (one or more segments of 3–8 alphanumerals, joined by hyphens) is accepted, but the implementation only recognizes certain kinds, which are listed in [`Intl.supportedValuesOf()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/supportedValuesOf#supported_calendar_types).
     - `collation`
-      - : The collation. Any syntactically valid string following the `type` grammar is accepted, but the implementation only recognizes certain kinds, which are listed in [`Intl.Locale.prototype.getCollations`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/Locale/getCollations#supported_collation_types).
+      - : The collation. Any syntactically valid string following the `type` grammar is accepted, but the implementation only recognizes certain kinds, which are listed in [`Intl.supportedValuesOf()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/supportedValuesOf#supported_collation_types).
     - `numberingSystem`
-      - : The numbering system. Any syntactically valid string following the `type` grammar is accepted, but the implementation only recognizes certain kinds, which are listed in [`Intl.Locale.prototype.getNumberingSystems`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/Locale/getNumberingSystems#supported_numbering_system_types).
+      - : The numbering system. Any syntactically valid string following the `type` grammar is accepted, but the implementation only recognizes certain kinds, which are listed in [`Intl.supportedValuesOf()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/supportedValuesOf#supported_numbering_system_types).
     - `caseFirst`
       - : The case-first sort option. Possible values are `"upper"`, `"lower"`, or `"false"`.
     - `hourCycle`
diff --git a/files/en-us/web/javascript/reference/global_objects/intl/locale/numberingsystem/index.md b/files/en-us/web/javascript/reference/global_objects/intl/locale/numberingsystem/index.md
index 87df933003f681b..57d37f85f3a7f57 100644
--- a/files/en-us/web/javascript/reference/global_objects/intl/locale/numberingsystem/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/intl/locale/numberingsystem/index.md
@@ -13,7 +13,7 @@ The **`numberingSystem`** accessor property of {{jsxref("Intl.Locale")}} instanc
 
 A numeral system is a system for expressing numbers. The `numberingSystem` property's value is set at construction time, either through the `nu` key of the locale identifier or through the `numberingSystem` option of the {{jsxref("Intl/Locale/Locale", "Intl.Locale()")}} constructor. The latter takes priority if they are both present; and if neither is present, the property has value `undefined`.
 
-For a list of supported numbering system types, see [`Intl.Locale.prototype.getNumberingSystems()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/Locale/getNumberingSystems#supported_numbering_system_types).
+For a list of supported numbering system types, see [`Intl.supportedValuesOf()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/supportedValuesOf#supported_numbering_system_types).
 
 ## Examples
 
diff --git a/files/en-us/web/javascript/reference/global_objects/intl/numberformat/formatrangetoparts/index.md b/files/en-us/web/javascript/reference/global_objects/intl/numberformat/formatrangetoparts/index.md
index 79ebdee27c0aedb..3601dabfe15167e 100644
--- a/files/en-us/web/javascript/reference/global_objects/intl/numberformat/formatrangetoparts/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/intl/numberformat/formatrangetoparts/index.md
@@ -24,55 +24,16 @@ formatRangeToParts(startRange, endRange)
 
 ### Return value
 
-An {{jsxref("Array")}} of objects containing the formatted range of numbers in parts.
-
-The structure of the returned looks like this:
-
-```js
-[
-  { type: "integer", value: "3", source: "startRange" },
-  { type: "literal", value: "-", source: "shared" },
-  { type: "integer", value: "5", source: "endRange" },
-  { type: "literal", value: " ", source: "shared" },
-  { type: "currency", value: "€", source: "shared" },
-];
-```
-
-Possible values for the `type` property include:
-
-- `currency`
-  - : The currency string, such as the symbols "$" and "€" or the name "Dollar", "Euro", depending on how `currencyDisplay` is specified.
-- `decimal`
-  - : The decimal separator string (".").
-- `fraction`
-  - : The fraction number.
-- `group`
-  - : The group separator string (",").
-- `infinity`
-  - : The {{jsxref("Infinity")}} string ("∞").
-- `integer`
-  - : The integer number.
-- `literal`
-  - : Any literal strings or whitespace in the formatted number.
-- `minusSign`
-  - : The minus sign string ("-").
-- `nan`
-  - : The {{jsxref("NaN")}} string ("NaN").
-- `plusSign`
-  - : The plus sign string ("+").
-- `percentSign`
-  - : The percent sign string ("%").
-- `unit`
-  - : The unit string, such as the "l" or "litres", depending on how `unitDisplay` is specified.
-
-Possible values for the `source` property include:
+An {{jsxref("Array")}} of objects containing the formatted range in parts. Each object has three properties, `type`, `value`, and `source`, each containing a string. The string concatenation of `value`, in the order provided, will result in the same string as {{jsxref("Intl/NumberFormat/formatRange", "formatRange()")}}. The `type` may have the same values as {{jsxref("Intl/NumberFormat/formatToParts", "formatToParts()")}}. The `source` can be one of the following:
 
 - `startRange`
-  - : The object is the start part of the range.
+  - : The token is a part of the start number.
 - `endRange`
-  - : The object is the end part of the range.
+  - : The token is a part of the end number.
 - `shared`
-  - : The object is a "shared" part of the range, such as a separator or currency.
+  - : The token is shared between the start and end; for example, the currency symbol. All literals that are part of the range pattern itself, such as the `"–"` separator, are also marked as `shared`.
+
+If the start and end numbers are equivalent, then the output has the same list of tokens as calling {{jsxref("Intl/NumberFormat/formatToParts", "formatToParts()")}} on the start number, with all tokens marked as `source: "shared"`.
 
 ### Exceptions
 
@@ -83,9 +44,9 @@ Possible values for the `source` property include:
 
 ## Examples
 
-### Comparing formatRange and formatRangeToParts
+### Using formatRangeToParts()
 
-`NumberFormat` outputs localized, opaque strings that cannot be manipulated directly:
+The `formatRange()` method outputs localized, opaque strings that cannot be manipulated directly:
 
 ```js
 const startRange = 3500;
@@ -100,8 +61,7 @@ console.log(formatter.formatRange(startRange, endRange));
 // "3.500,00–9.500,00 €"
 ```
 
-However, for many user interfaces there is a need to customize the formatting of this string.
-The `formatRangeToParts` method enables locale-aware formatting of strings produced by `NumberFormat` formatters by providing you the string in parts:
+However, in many user interfaces you may want to customize the formatting of this string, or interleave it with other texts. The `formatRangeToParts()` method produces the same information in parts:
 
 ```js
 console.log(formatter.formatRangeToParts(startRange, endRange));
@@ -136,4 +96,3 @@ console.log(formatter.formatRangeToParts(startRange, endRange));
 
 - {{jsxref("Intl.NumberFormat")}}
 - {{jsxref("Intl/NumberFormat/format", "Intl.NumberFormat.prototype.format()")}}
-- {{jsxref("Intl/DateTimeFormat/formatRangeToParts", "Intl.DateTimeFormat.prototype.formatRangeToParts()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/intl/numberformat/formattoparts/index.md b/files/en-us/web/javascript/reference/global_objects/intl/numberformat/formattoparts/index.md
index da6c36e399691ee..9a22bc6203fb197 100644
--- a/files/en-us/web/javascript/reference/global_objects/intl/numberformat/formattoparts/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/intl/numberformat/formattoparts/index.md
@@ -7,7 +7,7 @@ browser-compat: javascript.builtins.Intl.NumberFormat.formatToParts
 
 {{JSRef}}
 
-The **`formatToParts()`** method of {{jsxref("Intl.NumberFormat")}} instances allows locale-aware formatting of strings produced by this `Intl.NumberFormat` object.
+The **`formatToParts()`** method of {{jsxref("Intl.NumberFormat")}} instances returns an array of objects representing each part of the formatted string that would be returned by {{jsxref("Intl/NumberFormat/format", "format()")}}. It is useful for building custom strings from the locale-specific tokens.
 
 {{EmbedInteractiveExample("pages/js/intl-numberformat-prototype-formattoparts.html")}}
 
@@ -24,67 +24,48 @@ formatToParts(number)
 
 ### Return value
 
-An {{jsxref("Array")}} of objects containing the formatted number in parts.
+An {{jsxref("Array")}} of objects containing the formatted number in parts. Each object has two properties, `type` and `value`, each containing a string. The string concatenation of `value`, in the order provided, will result in the same string as {{jsxref("Intl/NumberFormat/format", "format()")}}. The `type` may be one of the following:
 
-## Description
-
-The `formatToParts()` method is useful for custom formatting of number
-strings. It returns an {{jsxref("Array")}} of objects containing the locale-specific
-tokens from which it possible to build custom strings while preserving the
-locale-specific parts. The structure the `formatToParts()` method returns,
-looks like this:
-
-```js
-[
-  { type: "integer", value: "3" },
-  { type: "group", value: "." },
-  { type: "integer", value: "500" },
-];
-```
-
-Possible types are the following:
-
-- `compact`
-  - : The exponent in `"long"` or `"short"` form, depending on how `compactDisplay` (which defaults to `short`) is specified when `notation` is set to `compact`.
-- `currency`
-  - : The currency string, such as the symbols "$" and "€" or the name "Dollar", "Euro", depending on how `currencyDisplay` is specified.
+- `literal`
+  - : Any string that's a part of the format pattern; for example `" "`. Note that common tokens like the decimal separator or the plus/minus signs have their own token types.
+- `integer`
+  - : The integral part of the number, or a segment of it if using grouping (controlled by `options.useGrouping`).
+- `group`
+  - : The group separator string, such as `","`. Only present when using grouping (controlled by `options.useGrouping`).
 - `decimal`
-  - : The decimal separator string (".").
-- `exponentInteger`
-  - : The exponent integer value, when `notation` is set to `scientific` or `engineering`.
-- `exponentMinusSign`
-  - : The exponent minus sign string ("-").
-- `exponentSeparator`
-  - : The exponent separator, when `notation` is set to `scientific` or `engineering`.
+  - : The decimal separator string, such as `"."`. Only present when `fraction` is present.
 - `fraction`
-  - : The fraction number.
-- `group`
-  - : The group separator string (",").
-- `infinity`
-  - : The {{jsxref("Infinity")}} string ("∞").
-- `integer`
-  - : The integer number.
-- `literal`
-  - : Any literal strings or whitespace in the formatted number.
-- `minusSign`
-  - : The minus sign string ("-").
+  - : The fractional part of the number.
+- `compact`
+  - : The compact exponent, such as `"M"` or `"thousands"`. Only present when `options.notation` is `"compact"`. The form (`"short"` or `"long"`) can be controlled via `options.compactDisplay`.
+- `exponentSeparator`
+  - : The exponent separator, such as `"E"`. Only present when `options.notation` is `"scientific"` or `"engineering"`.
+- `exponentMinusSign`
+  - : The exponent minus sign string, such as `"-"`. Only present when `options.notation` is `"scientific"` or `"engineering"` and the exponent is negative.
+- `exponentInteger`
+  - : The exponent's integer value. Only present when `options.notation` is `"scientific"` or `"engineering"`.
 - `nan`
-  - : The {{jsxref("NaN")}} string ("NaN").
+  - : A string representing {{jsxref("NaN")}}, such as `"NaN"`. This is the sole token representing the number itself when the number is `NaN`.
+- `infinity`
+  - : A string representing {{jsxref("Infinity")}} or `-Infinity`, such as `"∞"`. This is the sole token representing the number itself when the number is `Infinity` or `-Infinity`.
 - `plusSign`
-  - : The plus sign string ("+").
+  - : The plus sign, such as `"+"`.
+- `minusSign`
+  - : The minus sign, such as `"-"`.
 - `percentSign`
-  - : The percent sign string ("%").
+  - : The percent sign, such as `"%"`. Only present when `options.style` is `"percent"`.
 - `unit`
-  - : The unit string, such as the "l" or "litres", depending on how `unitDisplay` is specified.
+  - : The unit string, such as `"l"` or `"litres"`. Only present when `options.style` is `"unit"`. The form (`"short"`, `"narrow"`, or `"long"`) can be controlled via `options.unitDisplay`.
+- `currency`
+  - : The currency string, such as `"$"`, `"€"`, `"Dollar"`, or `"Euro"`. Only present when `options.style` is `"currency"`. The form (`"code"`, `"symbol"`, `"narrowSymbol"`, or `"name"`) can be controlled via `options.currencyDisplay`.
 - `unknown`
-  - : The string for `unknown` type results.
+  - : Reserved for any token that's not recognized as one of the above; should be rarely encountered.
 
 ## Examples
 
-### Comparing format and formatToParts
+### Using formatToParts()
 
-`NumberFormat` outputs localized, opaque strings that cannot be manipulated
-directly:
+The `format()` method outputs localized, opaque strings that cannot be manipulated directly:
 
 ```js
 const number = 3500;
@@ -98,10 +79,7 @@ formatter.format(number);
 // "3.500,00 €"
 ```
 
-However, in many User Interfaces there is a desire to customize the formatting of this
-string. The `formatToParts` method enables locale-aware formatting of
-strings produced by `NumberFormat` formatters by providing you the string
-in parts:
+However, in many user interfaces you may want to customize the formatting of this string, or interleave it with other texts. The `formatToParts()` method produces the same information in parts:
 
 ```js
 formatter.formatToParts(number);
@@ -118,11 +96,7 @@ formatter.formatToParts(number);
 ];
 ```
 
-Now the information is available separately and it can be formatted and concatenated
-again in a customized way. For example by using {{jsxref("Array.prototype.map()")}},
-[arrow functions](/en-US/docs/Web/JavaScript/Reference/Functions/Arrow_functions),
-a [switch statement](/en-US/docs/Web/JavaScript/Reference/Statements/switch),
-[template literals](/en-US/docs/Web/JavaScript/Reference/Template_literals), and {{jsxref("Array.prototype.reduce()")}}.
+Now the information is available separately and it can be formatted and concatenated again in a customized way. For example by using {{jsxref("Array.prototype.map()")}}, [arrow functions](/en-US/docs/Web/JavaScript/Reference/Functions/Arrow_functions), a [switch statement](/en-US/docs/Web/JavaScript/Reference/Statements/switch), [template literals](/en-US/docs/Web/JavaScript/Reference/Template_literals), and {{jsxref("Array.prototype.join()")}}, to insert additional markup for certain components.
 
 ```js
 const numberString = formatter
@@ -135,12 +109,8 @@ const numberString = formatter
         return value;
     }
   })
-  .reduce((string, part) => string + part);
-```
+  .join("");
 
-This will make the currency bold, when using the `formatToParts()` method.
-
-```js
 console.log(numberString);
 // "3.500,00 <strong>€</strong>"
 ```
@@ -157,4 +127,3 @@ console.log(numberString);
 
 - {{jsxref("Intl.NumberFormat")}}
 - {{jsxref("Intl/NumberFormat/format", "Intl.NumberFormat.prototype.format()")}}
-- {{jsxref("Intl/DateTimeFormat/formatToParts", "Intl.DateTimeFormat.prototype.formatToParts()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/intl/numberformat/index.md b/files/en-us/web/javascript/reference/global_objects/intl/numberformat/index.md
index 7fec244a3dcb401..e420ecfc8c94091 100644
--- a/files/en-us/web/javascript/reference/global_objects/intl/numberformat/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/intl/numberformat/index.md
@@ -149,3 +149,4 @@ For an exhaustive list of options, see the [`Intl.NumberFormat()` constructor](/
 
 - [Polyfill of `Intl.NumberFormat` in FormatJS](https://formatjs.github.io/docs/polyfills/intl-numberformat/)
 - {{jsxref("Intl")}}
+- {{jsxref("Number.prototype.toLocaleString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/intl/numberformat/numberformat/index.md b/files/en-us/web/javascript/reference/global_objects/intl/numberformat/numberformat/index.md
index d3ea989419323d2..e5b6827617aa9dc 100644
--- a/files/en-us/web/javascript/reference/global_objects/intl/numberformat/numberformat/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/intl/numberformat/numberformat/index.md
@@ -48,7 +48,7 @@ Intl.NumberFormat(locales, options)
   - : The locale matching algorithm to use. Possible values are `"lookup"` and `"best fit"`; the default is `"best fit"`.
     For information about this option, see [Locale identification and negotiation](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl#locale_identification_and_negotiation).
 - `numberingSystem`
-  - : The numbering system to use for number formatting, such as `"arab"`, `"hans"`, `"mathsans"`, and so on. For a list of supported numbering system types, see [`Intl.Locale.prototype.getNumberingSystems()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/Locale/getNumberingSystems#supported_numbering_system_types). This option can also be set through the `nu` Unicode extension key; if both are provided, this `options` property takes precedence.
+  - : The numbering system to use for number formatting, such as `"arab"`, `"hans"`, `"mathsans"`, and so on. For a list of supported numbering system types, see [`Intl.supportedValuesOf()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/supportedValuesOf#supported_numbering_system_types). This option can also be set through the `nu` Unicode extension key; if both are provided, this `options` property takes precedence.
 
 #### Style options
 
@@ -65,7 +65,7 @@ Depending on the `style` used, some of them may be ignored, and others may be re
     - `"unit"`
       - : For unit formatting.
 - `currency`
-  - : The currency to use in currency formatting. Possible values are the ISO 4217 currency codes, such as `"USD"` for the US dollar, `"EUR"` for the euro, or `"CNY"` for the Chinese RMB — see the [Current currency & funds code list](https://en.wikipedia.org/wiki/ISO_4217#List_of_ISO_4217_currency_codes). There is no default value; if the `style` is `"currency"`, the `currency` property must be provided. It is normalized to uppercase.
+  - : The currency to use in currency formatting. Possible values are the ISO 4217 currency codes, such as `"USD"` for the US dollar, `"EUR"` for the euro, or `"CNY"` for the Chinese RMB — see [`Intl.supportedValuesOf()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/supportedValuesOf#supported_currency_identifiers). There is no default value; if the `style` is `"currency"`, the `currency` property must be provided. It is normalized to uppercase.
 - `currencyDisplay`
   - : How to display the currency in currency formatting.
     - `"code"`
@@ -79,7 +79,7 @@ Depending on the `style` used, some of them may be ignored, and others may be re
 - `currencySign`
   - : In many locales, accounting format means to wrap the number with parentheses instead of appending a minus sign. Possible values are `"standard"` and `"accounting"`; the default is `"standard"`.
 - `unit`
-  - : The unit to use in `unit` formatting, Possible values are core unit identifiers, defined in [UTS #35, Part 2, Section 6](https://unicode.org/reports/tr35/tr35-general.html#Unit_Elements). A [subset](https://tc39.es/ecma402/#table-sanctioned-single-unit-identifiers) of units from the [full list](https://github.com/unicode-org/cldr/blob/main/common/validity/unit.xml) was selected for use in ECMAScript. Pairs of simple units can be concatenated with "-per-" to make a compound unit. There is no default value; if the `style` is `"unit"`, the `unit` property must be provided.
+  - : The unit to use in `unit` formatting, Possible values are listed in [`Intl.supportedValuesOf()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/supportedValuesOf#supported_unit_identifiers). Pairs of simple units can be concatenated with "-per-" to make a compound unit. There is no default value; if the `style` is `"unit"`, the `unit` property must be provided.
 - `unitDisplay`
   - : The unit formatting style to use in `unit` formatting. Possible values are:
     - `"short"` (default)
diff --git a/files/en-us/web/javascript/reference/global_objects/intl/numberformat/resolvedoptions/index.md b/files/en-us/web/javascript/reference/global_objects/intl/numberformat/resolvedoptions/index.md
index c82a4fc9f737ac9..c6ef362d73c43fd 100644
--- a/files/en-us/web/javascript/reference/global_objects/intl/numberformat/resolvedoptions/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/intl/numberformat/resolvedoptions/index.md
@@ -28,11 +28,11 @@ A new object with properties reflecting the options computed during the initiali
 - `locale`
   - : The BCP 47 language tag for the locale actually used, determined by the [locale negotiation](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl#locale_identification_and_negotiation) process. Only the `nu` Unicode extension key, if requested, may be included in the output.
 - `numberingSystem`
-  - : The value provided for this property in the `options` argument, or using the Unicode extension key `"nu"`, with default filled in as needed. It is a supported [numbering system](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/Locale/getNumberingSystems#supported_numbering_system_types) for this locale. The default is locale dependent.
+  - : The value provided for this property in the `options` argument, or using the Unicode extension key `"nu"`, with default filled in as needed. It is a supported [numbering system](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/supportedValuesOf#supported_numbering_system_types) for this locale. The default is locale dependent.
 - `style`
   - : The value provided for this property in the `options` argument, with default filled in as needed. It is either `"decimal"`, `"percent"`, `"currency"`, or `"unit"`. The default is `"decimal"`.
 - `currency` {{optional_inline}}
-  - : The value provided for this property in the `options` argument. It is only present if `style` is `"currency"`. It is an [ISO 4217 currency code](https://en.wikipedia.org/wiki/ISO_4217#List_of_ISO_4217_currency_codes). It is required if `style` is `"currency"` so there is no default.
+  - : The value provided for this property in the `options` argument. It is only present if `style` is `"currency"`. It is an ISO 4217 currency code; see [`Intl.supportedValuesOf()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/supportedValuesOf#supported_currency_identifiers). It is required if `style` is `"currency"` so there is no default.
 - `currencyDisplay` {{optional_inline}}
   - : The value provided for this property in the `options` argument, with default filled in as needed. It is only present if `style` is `"currency"`. It is either `"code"`, `"symbol"`, `"narrowSymbol"`, or `"name"`. The default is `"symbol"`.
 - `currencySign` {{optional_inline}}
diff --git a/files/en-us/web/javascript/reference/global_objects/intl/relativetimeformat/formattoparts/index.md b/files/en-us/web/javascript/reference/global_objects/intl/relativetimeformat/formattoparts/index.md
index b741feb9456817c..a2c27500eed205e 100644
--- a/files/en-us/web/javascript/reference/global_objects/intl/relativetimeformat/formattoparts/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/intl/relativetimeformat/formattoparts/index.md
@@ -7,7 +7,7 @@ browser-compat: javascript.builtins.Intl.RelativeTimeFormat.formatToParts
 
 {{JSRef}}
 
-The **`formatToParts()`** method of {{jsxref("Intl.RelativeTimeFormat")}} instances returns an {{jsxref("Array")}} of objects representing the relative time format in parts that can be used for custom locale-aware formatting.
+The **`formatToParts()`** method of {{jsxref("Intl.RelativeTimeFormat")}} instances returns an array of objects representing each part of the formatted string that would be returned by {{jsxref("Intl/RelativeTimeFormat/format", "format()")}}. It is useful for building custom strings from the locale-specific tokens.
 
 {{EmbedInteractiveExample("pages/js/intl-relativetimeformat-prototype-formattoparts.html")}}
 
@@ -26,15 +26,13 @@ formatToParts(value, unit)
 
 ### Return value
 
-An {{jsxref("Array")}} of objects containing the formatted relative time in parts.
+An {{jsxref("Array")}} of objects containing the formatted relative time in parts. Each object has two or three properties, `type`, `value`, and optionally `unit`, each containing a string. The string concatenation of `value`, in the order provided, will result in the same string as {{jsxref("Intl/RelativeTimeFormat/format", "format()")}}. The parts can be thought of as directly obtained from calling {{jsxref("Intl/NumberFormat/formatToParts", "Intl.NumberFormat.prototype.formatToParts()")}} with the numeric value, passing only the `numberingSystem` option, and then adding additional `type: "literal"` tokens, such as `"in "`, `" days ago"`, etc. All tokens that are produced by the `NumberFormat` have an additional `unit` property, which is the singular form of the input `unit`; this is for programmatic usage and is not localized. The localized unit is output as a part of a literal token.
 
-## Description
-
-The `Intl.RelativeTimeFormat.prototype.formatToParts` method is a version of the format method which it returns an array of objects which represent "parts" of the object, separating the formatted number into its constituent parts and separating it from other surrounding text. These objects have two properties: type a `NumberFormat` formatToParts type, and value, which is the String which is the component of the output. If a "part" came from `NumberFormat`, it will have a unit property which indicates the unit being formatted; literals which are part of the larger frame will not have this property.
+When `options.numeric` is `"auto"`, and there's a special string for the value, the returned array is a single literal token.
 
 ## Examples
 
-### Using formatToParts
+### Using formatToParts()
 
 ```js
 const rtf = new Intl.RelativeTimeFormat("en", { numeric: "auto" });
@@ -62,3 +60,4 @@ rtf.formatToParts(100, "day");
 ## See also
 
 - {{jsxref("Intl.RelativeTimeFormat")}}
+- {{jsxref("Intl/RelativeTimeFormat/format", "Intl.RelativeTimeFormat.prototype.format()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/intl/relativetimeformat/relativetimeformat/index.md b/files/en-us/web/javascript/reference/global_objects/intl/relativetimeformat/relativetimeformat/index.md
index 1d09ac02591af91..96b4e09198c8b92 100644
--- a/files/en-us/web/javascript/reference/global_objects/intl/relativetimeformat/relativetimeformat/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/intl/relativetimeformat/relativetimeformat/index.md
@@ -39,7 +39,7 @@ new Intl.RelativeTimeFormat(locales, options)
     - `localeMatcher`
       - : The locale matching algorithm to use. Possible values are `"lookup"` and `"best fit"`; the default is `"best fit"`. For information about this option, see [Locale identification and negotiation](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl#locale_identification_and_negotiation).
     - `numberingSystem`
-      - : The numbering system to use for number formatting, such as `"arab"`, `"hans"`, `"mathsans"`, and so on. For a list of supported numbering system types, see [`Intl.Locale.prototype.getNumberingSystems()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/Locale/getNumberingSystems#supported_numbering_system_types). This option can also be set through the `nu` Unicode extension key; if both are provided, this `options` property takes precedence.
+      - : The numbering system to use for number formatting, such as `"arab"`, `"hans"`, `"mathsans"`, and so on. For a list of supported numbering system types, see [`Intl.supportedValuesOf()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/supportedValuesOf#supported_numbering_system_types). This option can also be set through the `nu` Unicode extension key; if both are provided, this `options` property takes precedence.
     - `style`
       - : The style of the formatted relative time. Possible values are:
         - `"long"` (default)
diff --git a/files/en-us/web/javascript/reference/global_objects/intl/relativetimeformat/resolvedoptions/index.md b/files/en-us/web/javascript/reference/global_objects/intl/relativetimeformat/resolvedoptions/index.md
index 437f8e7d3e3d3d6..77a2d830f6b539c 100644
--- a/files/en-us/web/javascript/reference/global_objects/intl/relativetimeformat/resolvedoptions/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/intl/relativetimeformat/resolvedoptions/index.md
@@ -32,7 +32,7 @@ A new object with properties reflecting the options computed during the initiali
 - `numeric`
   - : The value provided for this property in the `options` argument, with default filled in as needed. It is either `"always"` or `"auto"`. The default is `"always"`.
 - `numberingSystem`
-  - : The value provided for this property in the `options` argument, or using the Unicode extension key `"nu"`, with default filled in as needed. It is a supported [numbering system](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/Locale/getNumberingSystems#supported_numbering_system_types) for this locale. The default is locale dependent.
+  - : The value provided for this property in the `options` argument, or using the Unicode extension key `"nu"`, with default filled in as needed. It is a supported [numbering system](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/supportedValuesOf#supported_numbering_system_types) for this locale. The default is locale dependent.
 
 ## Examples
 
diff --git a/files/en-us/web/javascript/reference/global_objects/intl/supportedvaluesof/index.md b/files/en-us/web/javascript/reference/global_objects/intl/supportedvaluesof/index.md
index ce779a1647bdb88..c043cde03855496 100644
--- a/files/en-us/web/javascript/reference/global_objects/intl/supportedvaluesof/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/intl/supportedvaluesof/index.md
@@ -14,6 +14,8 @@ Duplicates are omitted and the array is sorted in ascending lexicographical orde
 The method can be used to feature-test whether values are supported in a particular implementation and download a polyfill only if necessary.
 It can also be used to build UIs that allow users to select their preferred localized values, for example when the UI is created from WebGL or server-side.
 
+This method is locale-unaware: it is possible that certain identifiers are only supported or preferred in certain locales. If you want to determine the preferred values for a specific locale, you should use the {{jsxref("Intl.Locale")}} object, such as {{jsxref("Intl/Locale/getCalendars", "Intl.Locale.prototype.getCalendars()")}}.
+
 {{EmbedInteractiveExample("pages/js/intl-supportedvaluesof.html", "taller")}}
 
 ## Syntax
@@ -25,14 +27,279 @@ Intl.supportedValuesOf(key)
 ### Parameters
 
 - `key`
-  - : A key string indicating the category of values to be returned. This is one of: `"calendar"`, `"collation"`, `"currency"`, `"numberingSystem"`, `"timeZone"`, `"unit"`.
+  - : A key string indicating the category of values to be returned. This is one of:
+    - `"calendar"`: see [supported calendar types](#supported_calendar_types)
+    - `"collation"`: see [supported collation types](#supported_collation_types)
+    - `"currency"`: see [supported currency identifiers](#supported_currency_identifiers)
+    - `"numberingSystem"`: see [supported numbering system types](#supported_numbering_system_types)
+    - `"timeZone"`: see [supported time zone identifiers](#supported_time_zone_identifiers)
+    - `"unit"`: see [supported unit identifiers](#supported_unit_identifiers)
 
 ### Return value
 
-A sorted array of unique string values indicating the values supported by the implementation for the given key.
-
-> [!NOTE]
-> While the IANA database changes from time to time, the Unicode CLDR database (which browsers use) keeps old time zone names for stability purposes. Some browsers may use the legacy name, while others override it with the new name. See {{jsxref("Intl/Locale/getTimeZones", "Intl.Locale.prototype.getTimeZones")}} for more information.
+A sorted array of unique string values indicating the values supported by the implementation for the given key. The values that could be returned are listed below.
+
+#### Supported calendar types
+
+Below are all values that are commonly supported by browsers for the `calendar` key. These values can be used for the `calendar` option or the `ca` [Unicode extension key](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl#locales_argument) when creating objects such as {{jsxref("Intl.DateTimeFormat")}}, as well as for creating {{jsxref("Temporal")}} date objects.
+
+| Value              | Description                                                                                      |
+| ------------------ | ------------------------------------------------------------------------------------------------ |
+| `buddhist`         | Thai Buddhist calendar                                                                           |
+| `chinese`          | Traditional Chinese calendar                                                                     |
+| `coptic`           | Coptic calendar                                                                                  |
+| `dangi`            | Traditional Korean calendar                                                                      |
+| `ethioaa`          | Ethiopic calendar, Amete Alem (epoch approx. 5493 B.C.E)                                         |
+| `ethiopic`         | Ethiopic calendar, Amete Mihret (epoch approx, 8 C.E.)                                           |
+| `gregory`          | Gregorian calendar                                                                               |
+| `hebrew`           | Traditional Hebrew calendar                                                                      |
+| `indian`           | Indian calendar                                                                                  |
+| `islamic`          | Hijri calendar                                                                                   |
+| `islamic-umalqura` | Hijri calendar, Umm al-Qura                                                                      |
+| `islamic-tbla`     | Hijri calendar, tabular (intercalary years [2,5,7,10,13,16,18,21,24,26,29] - astronomical epoch) |
+| `islamic-civil`    | Hijri calendar, tabular (intercalary years [2,5,7,10,13,16,18,21,24,26,29] - civil epoch)        |
+| `islamic-rgsa`     | Hijri calendar, Saudi Arabia sighting                                                            |
+| `iso8601`          | ISO calendar (Gregorian calendar using the ISO 8601 calendar week rules)                         |
+| `japanese`         | Japanese Imperial calendar                                                                       |
+| `persian`          | Persian calendar                                                                                 |
+| `roc`              | Republic of China calendar                                                                       |
+
+The types below are specified in CLDR data, but are deprecated, are discouraged from explicit usage, and/or may not be indicated by browsers as supported for various reasons. Avoid using them:
+
+| Value                            | Description                          | Notes                                                                                                                     |
+| -------------------------------- | ------------------------------------ | ------------------------------------------------------------------------------------------------------------------------- |
+| `islamicc` {{deprecated_inline}} | Civil (algorithmic) Arabic calendar. | This is an alias for `islamic-civil` and therefore is not returned by `supportedValuesOf()`. Use `islamic-civil` instead. |
+
+References:
+
+- [CLDR Calendar type keys](https://github.com/unicode-org/cldr/blob/main/common/bcp47/calendar.xml)
+- [UTS 35, Dates](https://unicode.org/reports/tr35/tr35-dates.html)
+
+#### Supported collation types
+
+Below are all values that are commonly supported by browsers for the `collation` key. These values can be used for the `collation` option or the `co` [Unicode extension key](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl#locales_argument) when creating objects such as {{jsxref("Intl.Collator")}}.
+
+| Value      | Description                                                                                                                                                                                      |
+| ---------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
+| `compat`   | A previous version of the ordering, for compatibility (for Arabic)                                                                                                                               |
+| `dict`     | Dictionary style ordering (such as in Sinhala). Also recognized as `dictionary`.                                                                                                                 |
+| `emoji`    | Recommended ordering for emoji characters                                                                                                                                                        |
+| `eor`      | European ordering rules                                                                                                                                                                          |
+| `phonebk`  | Phonebook style ordering (such as in German). Also recognized as `phonebook`.                                                                                                                    |
+| `phonetic` | Phonetic ordering (sorting based on pronunciation; for Lingala)                                                                                                                                  |
+| `pinyin`   | Pinyin ordering for Latin and for CJK characters (used in Chinese)                                                                                                                               |
+| `searchjl` | Special collation type for Korean initial consonant search. **Warning:** This collation is not for sorting, even though you can only use it with {{jsxref("Intl.Collator")}} of `usage: "sort"`. |
+| `stroke`   | Pinyin ordering for Latin, stroke order for CJK characters (used in Chinese)                                                                                                                     |
+| `trad`     | Traditional style ordering (such as in Spanish). Also recognized as `traditional`.                                                                                                               |
+| `unihan`   | Pinyin ordering for Latin, Unihan radical-stroke ordering for CJK characters (used in Chinese)                                                                                                   |
+| `zhuyin`   | Pinyin ordering for Latin, zhuyin order for Bopomofo and CJK characters (used in Chinese)                                                                                                        |
+
+The types below are specified in CLDR data, but are deprecated, are discouraged from explicit usage, and/or may not be indicated by browsers as supported for various reasons. Avoid using them:
+
+| Value                            | Description                                                                                                             | Notes                                                                                                                                                                                                                                                                                                               |
+| -------------------------------- | ----------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| `big5han` {{deprecated_inline}}  | Pinyin ordering for Latin, big5 charset ordering for CJK characters (used in Chinese)                                   | Deprecated.                                                                                                                                                                                                                                                                                                         |
+| `direct` {{deprecated_inline}}   | Binary code point order (used in Hindi)                                                                                 | Deprecated.                                                                                                                                                                                                                                                                                                         |
+| `ducet`                          | The default Unicode collation element table order                                                                       | The `ducet` collation type is not available to the Web.                                                                                                                                                                                                                                                             |
+| `gb2312` {{deprecated_inline}}   | Pinyin ordering for Latin, gb2312han charset ordering for CJK characters (for Chinese). Also recognized as `gb2312han`. | Deprecated.                                                                                                                                                                                                                                                                                                         |
+| `reformed` {{deprecated_inline}} | Reformed ordering (such as Swedish)                                                                                     | Deprecated. This is the old name for the default ordering for Swedish [whose collation naming used to differ from other languages](https://unicode-org.atlassian.net/browse/CLDR-15603). Since this was the default, request `sv` instead of requesting `sv-u-co-reformed`.                                         |
+| `search`                         | Special collation type for string search                                                                                | Do not use as a collation type, since in {{jsxref("Intl.Collator")}}, this collation is activated via the `usage: "search"` option. There is currently no API for substring search, so this is currently only good for filtering a list of strings by trying a full-string match of the key against each list item. |
+| `standard`                       | Default ordering for each language, except Chinese (and, previously, Swedish)                                           | Do not use explicitly. In general, it's unnecessary to specify this explicitly and specifying this for Swedish is problematic due to the different meaning for Swedish in the past.                                                                                                                                 |
+
+References:
+
+- [CLDR Collation type keys](https://github.com/unicode-org/cldr/blob/main/common/bcp47/collation.xml)
+- [UTS 35, Collation](https://unicode.org/reports/tr35/tr35-collation.html)
+
+#### Supported currency identifiers
+
+Currency identifiers are three-letter uppercase codes defined in ISO 4217. These values can be used for the `currency` option when creating objects such as {{jsxref("Intl.NumberFormat")}}, as well as for {{jsxref("Intl/DisplayNames/of", "Intl.DisplayNames.prototype.of()")}}. There are over 300 identifiers in common use so we won't list them. For an exhaustive list of possible identifiers, see the [Wikipedia article](https://en.wikipedia.org/wiki/ISO_4217#List_of_ISO_4217_currency_codes).
+
+References:
+
+- [CLDR Currency type keys](https://github.com/unicode-org/cldr/blob/main/common/bcp47/currency.xml)
+- [ISO 4217 Currency codes](https://www.iso.org/iso-4217-currency-codes.html)
+- [UTS 35, Currencies](https://unicode.org/reports/tr35/tr35-numbers.html#Currencies)
+
+#### Supported numbering system types
+
+Below are all values that are commonly supported by browsers for the `numberingSystem` key. These values can be used for the `numberingSystem` option or the `nu` [Unicode extension key](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl#locales_argument) when creating objects such as {{jsxref("Intl.NumberFormat")}}. For the rows with "digit characters", the runtime translates the digits one-by-one without extra actions. The others marked as "algorithmic" need additional algorithms to translate the digits. The higher the Unicode code point is, the newer the numbering system is and the more likely it is unsupported by all browsers.
+
+| Value      | Description                                                                | Digit characters                                                                                        |
+| ---------- | -------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------- |
+| `adlm`     | Adlam digits                                                               | `𞥐𞥑𞥒𞥓𞥔𞥕𞥖𞥗𞥘𞥙` (U+1E950 to U+1E959)                                                                       |
+| `ahom`     | Ahom digits                                                                | `𑜰𑜱𑜲𑜳𑜴𑜵𑜶𑜷𑜸𑜹` (U+11730 to U+11739)                                                                       |
+| `arab`     | Arabic-Indic digits                                                        | `٠١٢٣٤٥٦٧٨٩` (U+0660 to U+0669)                                                                         |
+| `arabext`  | Extended Arabic-Indic digits                                               | `۰۰۱۲۳۴۵۶۷۸۹` (U+06F0 to U+06F9)                                                                        |
+| `armn`     | Armenian upper case numerals                                               | algorithmic                                                                                             |
+| `armnlow`  | Armenian lower case numerals                                               | algorithmic                                                                                             |
+| `bali`     | Balinese digits                                                            | `᭐᭑᭒᭓᭔᭕᭖᭗᭘᭙` (U+1B50 to U+1B59)                                                                         |
+| `beng`     | Bengali digits                                                             | `০১২৩৪৫৬৭৮৯` (U+09E6 to U+09EF)                                                                         |
+| `bhks`     | Bhaiksuki digits                                                           | `𑱐𑱑𑱒𑱓𑱔𑱕𑱖𑱗𑱘𑱙` (U+11C50 to U+11C59)                                                                       |
+| `brah`     | Brahmi digits                                                              | `𑁦𑁧𑁨𑁩𑁪𑁫𑁬𑁭𑁮𑁯` (U+11066 to U+1106F)                                                                       |
+| `cakm`     | Chakma digits                                                              | `𑄶𑄷𑄸𑄹𑄺𑄻𑄼𑄽𑄾𑄿` (U+11136 to U+1113F)                                                                       |
+| `cham`     | Cham digits                                                                | `꩐꩑꩒꩓꩔꩕꩖꩗꩘꩙` (U+AA50 to U+AA59)                                                                         |
+| `cyrl`     | Cyrillic numerals                                                          | algorithmic                                                                                             |
+| `deva`     | Devanagari digits                                                          | `०१२३४५६७८९` (U+0966 to U+096F)                                                                         |
+| `diak`     | Dives Akuru digits                                                         | `𑥐𑥑𑥒𑥓𑥔𑥕𑥖𑥗𑥘𑥙` (U+11950 to U+11959)                                                                       |
+| `ethi`     | Ethiopic numerals                                                          | algorithmic                                                                                             |
+| `fullwide` | Full width digits                                                          | `０１２３４５６７８９` (U+FF10 to U+FF19)                                                               |
+| `gara`     | Garay digits                                                               | `𐵀𐵁𐵂𐵃𐵄𐵅𐵆𐵇𐵈𐵉` (U+10D40 to U+10D49)                                                                       |
+| `geor`     | Georgian numerals                                                          | algorithmic                                                                                             |
+| `gong`     | Gunjala Gondi digits                                                       | `𑶠𑶡𑶢𑶣𑶤𑶥𑶦𑶧𑶨𑶩` (U+11DA0 to U+11DA9)                                                                       |
+| `gonm`     | Masaram Gondi digits                                                       | `𑵐𑵑𑵒𑵓𑵔𑵕𑵖𑵗𑵘𑵙` (U+11D50 to U+11D59)                                                                       |
+| `grek`     | Greek upper case numerals                                                  | algorithmic                                                                                             |
+| `greklow`  | Greek lower case numerals                                                  | algorithmic                                                                                             |
+| `gujr`     | Gujarati digits                                                            | `૦૧૨૩૪૫૬૭૮૯` (U+0AE6 to U+0AEF)                                                                         |
+| `gukh`     | Gurung Khema digits                                                        | `𖄰𖄱𖄲𖄳𖄴𖄵𖄶𖄷𖄸𖄹` (U+16130 to U+16139)                                                                       |
+| `guru`     | Gurmukhi digits                                                            | `੦੧੨੩੪੫੬੭੮੯` (U+0A66 to U+0A6F)                                                                         |
+| `hanidays` | Han-character day-of-month numbering for lunar/other traditional calendars |                                                                                                         |
+| `hanidec`  | Positional decimal system using Chinese number ideographs as digits        | `〇一二三四五六七八九` (U+3007, U+4E00, U+4E8C, U+4E09, U+56DB, U+4E94, U+516D, U+4E03, U+516B, U+4E5D) |
+| `hans`     | Simplified Chinese numerals                                                | algorithmic                                                                                             |
+| `hansfin`  | Simplified Chinese financial numerals                                      | algorithmic                                                                                             |
+| `hant`     | Traditional Chinese numerals                                               | algorithmic                                                                                             |
+| `hantfin`  | Traditional Chinese financial numerals                                     | algorithmic                                                                                             |
+| `hebr`     | Hebrew numerals                                                            | algorithmic                                                                                             |
+| `hmng`     | Pahawh Hmong digits                                                        | `𖭐𖭑𖭒𖭓𖭔𖭕𖭖𖭗𖭘𖭙` (U+16B50 to U+16B59)                                                                       |
+| `hmnp`     | Nyiakeng Puachue Hmong digits                                              | `𞅀𞅁𞅂𞅃𞅄𞅅𞅆𞅇𞅈𞅉` (U+1E140 to U+1E149)                                                                       |
+| `java`     | Javanese digits                                                            | `꧐꧑꧒꧓꧔꧕꧖꧗꧘꧙` (U+A9D0 to U+A9D9)                                                                         |
+| `jpan`     | Japanese numerals                                                          | algorithmic                                                                                             |
+| `jpanfin`  | Japanese financial numerals                                                | algorithmic                                                                                             |
+| `jpanyear` | Japanese first-year Gannen numbering for Japanese calendar                 | algorithmic                                                                                             |
+| `kali`     | Kayah Li digits                                                            | `꤀꤁꤂꤃꤄꤅꤆꤇꤈꤉` (U+A900 to U+A909)                                                                         |
+| `kawi`     | Kawi digits                                                                | `𑽐𑽑𑽒𑽓𑽔𑽕𑽖𑽗𑽘𑽙` (U+11F50 to U+11F59)                                                                       |
+| `khmr`     | Khmer digits                                                               | `០១២៣៤៥៦៧៨៩` (U+17E0 to U+17E9)                                                                         |
+| `knda`     | Kannada digits                                                             | `೦೧೨೩೪೫೬೭೮೯` (U+0CE6 to U+0CEF)                                                                         |
+| `krai`     | Kirat Rai digits                                                           | `𖵰𖵱𖵲𖵳𖵴𖵵𖵶𖵷𖵸𖵹` (U+16D70 to U+16D79)                                                                       |
+| `lana`     | Tai Tham Hora (secular) digits                                             | `᪀᪁᪂᪃᪄᪅᪆᪇᪈᪉` (U+1A80 to U+1A89)                                                                         |
+| `lanatham` | Tai Tham (ecclesiastical) digits                                           | `᪐᪑᪒᪓᪔᪕᪖᪗᪘᪙` (U+1A90 to U+1A99)                                                                         |
+| `laoo`     | Lao digits                                                                 | `໐໑໒໓໔໕໖໗໘໙` (U+0ED0 to U+0ED9)                                                                         |
+| `latn`     | Latin digits                                                               | `0123456789` (U+0030 to U+0039)                                                                         |
+| `lepc`     | Lepcha digits                                                              | `᱀᱁᱂᱃᱄᱅᱆᱇᱈᱉` (U+1C40 to U+1C49)                                                                         |
+| `limb`     | Limbu digits                                                               | `᥆᥇᥈᥉᥊᥋᥌᥍᥎᥏` (U+1946 to U+194F)                                                                         |
+| `mathbold` | Mathematical bold digits                                                   | `𝟎𝟏𝟐𝟑𝟒𝟓𝟔𝟕𝟖𝟗` (U+1D7CE to U+1D7D7)                                                                       |
+| `mathdbl`  | Mathematical double-struck digits                                          | `𝟘𝟙𝟚𝟛𝟜𝟝𝟞𝟟𝟠𝟡` (U+1D7D8 to U+1D7E1)                                                                       |
+| `mathmono` | Mathematical monospace digits                                              | `𝟶𝟷𝟸𝟹𝟺𝟻𝟼𝟽𝟾𝟿` (U+1D7F6 to U+1D7FF)                                                                       |
+| `mathsanb` | Mathematical sans-serif bold digits                                        | `𝟬𝟭𝟮𝟯𝟰𝟱𝟲𝟳𝟴𝟵` (U+1D7EC to U+1D7F5)                                                                       |
+| `mathsans` | Mathematical sans-serif digits                                             | `𝟢𝟣𝟤𝟥𝟦𝟧𝟨𝟩𝟪𝟫` (U+1D7E2 to U+1D7EB)                                                                       |
+| `mlym`     | Malayalam digits                                                           | `൦൧൨൩൪൫൬൭൮൯` (U+0D66 to U+0D6F)                                                                         |
+| `modi`     | Modi digits                                                                | `𑙐𑙑𑙒𑙓𑙔𑙕𑙖𑙗𑙘𑙙` (U+11650 to U+11659)                                                                       |
+| `mong`     | Mongolian digits                                                           | `᠐᠑᠒᠓᠔᠕᠖᠗᠘᠙` (U+1810 to U+1819)                                                                         |
+| `mroo`     | Mro digits                                                                 | `𖩠𖩡𖩢𖩣𖩤𖩥𖩦𖩧𖩨𖩩` (U+16A60 to U+16A69)                                                                       |
+| `mtei`     | Meetei Mayek digits                                                        | `꯰꯱꯲꯳꯴꯵꯶꯷꯸꯹` (U+ABF0 to U+ABF9)                                                                         |
+| `mymr`     | Myanmar digits                                                             | `၀၁၂၃၄၅၆၇၈၉` (U+1040 to U+1049)                                                                         |
+| `mymrepka` | Myanmar Eastern Pwo Karen digits                                           | `𑛚𑛛𑛜𑛝𑛞𑛟𑛠𑛡𑛢𑛣` (U+116DA to U+116E3)                                                                       |
+| `mymrpao`  | Myanmar Pao digits                                                         | `𑛐𑛑𑛒𑛓𑛔𑛕𑛖𑛗𑛘𑛙` (U+116D0 to U+116D9)                                                                       |
+| `mymrshan` | Myanmar Shan digits                                                        | `႐႑႒႓႔႕႖႗႘႙` (U+1090 to U+1099)                                                                         |
+| `mymrtlng` | Myanmar Tai Laing digits                                                   | `꧰꧱꧲꧳꧴꧵꧶꧷꧸꧹` (U+A9F0 to U+A9F9)                                                                         |
+| `nagm`     | Nag Mundari digits                                                         | `𞓰𞓱𞓲𞓳𞓴𞓵𞓶𞓷𞓸𞓹` (U+1E4F0 to U+1E4F9)                                                                       |
+| `newa`     | Newa digits                                                                | `𑑐𑑑𑑒𑑓𑑔𑑕𑑖𑑗𑑘𑑙` (U+11450 to U+11459)                                                                       |
+| `nkoo`     | N'Ko digits                                                                | `߀߁߂߃߄߅߆߇߈߉` (U+07C0 to U+07C9)                                                                         |
+| `olck`     | Ol Chiki digits                                                            | `᱐᱑᱒᱓᱔᱕᱖᱗᱘᱙` (U+1C50 to U+1C59)                                                                         |
+| `onao`     | Ol Onal digits                                                             | `𞗱𞗲𞗳𞗴𞗵𞗶𞗷𞗸𞗹𞗺` (U+1E5F1 to U+1E5FA)                                                                       |
+| `orya`     | Oriya digits                                                               | `୦୧୨୩୪୫୬୭୮୯` (U+0B66 to U+0B6F)                                                                         |
+| `osma`     | Osmanya digits                                                             | `𐒠𐒡𐒢𐒣𐒤𐒥𐒦𐒧𐒨𐒩` (U+104A0 to U+104A9)                                                                       |
+| `outlined` | Legacy computing outlined digits                                           | `𜳰𜳱𜳲𜳳𜳴𜳵𜳶𜳷𜳸𜳹` (U+1CCF0 to U+1CCF9)                                                                       |
+| `rohg`     | Hanifi Rohingya digits                                                     | `𐴰𐴱𐴲𐴳𐴴𐴵𐴶𐴷𐴸𐴹` (U+10D30 to U+10D39)                                                                       |
+| `roman`    | Roman upper case numerals                                                  | algorithmic                                                                                             |
+| `romanlow` | Roman lowercase numerals                                                   | algorithmic                                                                                             |
+| `saur`     | Saurashtra digits                                                          | `꣐꣑꣒꣓꣔꣕꣖꣗꣘꣙` (U+A8D0 to U+A8D9)                                                                         |
+| `segment`  | Legacy computing segmented digits                                          | `🯰🯱🯲🯳🯴🯵🯶🯷🯸🯹` (U+1FBF0 to U+1FBF9)                                                                       |
+| `shrd`     | Sharada digits                                                             | `𑇐𑇑𑇒𑇓𑇔𑇕𑇖𑇗𑇘𑇙` (U+111D0 to U+111D9)                                                                       |
+| `sind`     | Khudawadi digits                                                           | `𑋰𑋱𑋲𑋳𑋴𑋵𑋶𑋷𑋸𑋹` (U+112F0 to U+112F9)                                                                       |
+| `sinh`     | Sinhala Lith digits                                                        | `෦෧෨෩෪෫෬෭෮෯` (U+0DE6 to U+0DEF)                                                                         |
+| `sora`     | Sora_Sompeng digits                                                        | `𑃰𑃱𑃲𑃳𑃴𑃵𑃶𑃷𑃸𑃹` (U+110F0 to U+110F9)                                                                       |
+| `sund`     | Sundanese digits                                                           | `᮰᮱᮲᮳᮴᮵᮶᮷᮸᮹` (U+1BB0 to U+1BB9)                                                                         |
+| `sunu`     | Sunuwar digits                                                             | `𑯰𑯱𑯲𑯳𑯴𑯵𑯶𑯷𑯸𑯹` (U+11BF0 to U+11BF9)                                                                       |
+| `takr`     | Takri digits                                                               | `𑛀𑛁𑛂𑛃𑛄𑛅𑛆𑛇𑛈𑛉` (U+116C0 to U+116C9)                                                                       |
+| `talu`     | New Tai Lue digits                                                         | `᧐᧑᧒᧓᧔᧕᧖᧗᧘᧙` (U+19D0 to U+19D9)                                                                         |
+| `taml`     | Tamil numerals                                                             | algorithmic                                                                                             |
+| `tamldec`  | Modern Tamil decimal digits                                                | `௦௧௨௩௪௫௬௭௮௯` (U+0BE6 to U+0BEF)                                                                         |
+| `telu`     | Telugu digits                                                              | `౦౧౨౩౪౫౬౭౮౯` (U+0C66 to U+0C6F)                                                                         |
+| `thai`     | Thai digits                                                                | `๐๑๒๓๔๕๖๗๘๙` (U+0E50 to U+0E59)                                                                         |
+| `tibt`     | Tibetan digits                                                             | `༠༡༢༣༤༥༦༧༨༩` (U+0F20 to U+0F29)                                                                         |
+| `tirh`     | Tirhuta digits                                                             | `𑓐𑓑𑓒𑓓𑓔𑓕𑓖𑓗𑓘𑓙` (U+114D0 to U+114D9)                                                                       |
+| `tnsa`     | Tangsa digits                                                              | `𖫀𖫁𖫂𖫃𖫄𖫅𖫆𖫇𖫈𖫉` (U+16AC0 to U+16AC9)                                                                       |
+| `vaii`     | Vai digits                                                                 | `꘠꘡꘢꘣꘤꘥꘦꘧꘨꘩` (U+A620 to U+A629)                                                                         |
+| `wara`     | Warang Citi digits                                                         | `𑣠𑣡𑣢𑣣𑣤𑣥𑣦𑣧𑣨𑣩` (U+118E0 to U+118E9)                                                                       |
+| `wcho`     | Wancho digits                                                              | `𞋰𞋱𞋲𞋳𞋴𞋵𞋶𞋷𞋸𞋹` (U+1E2F0 to U+1E2F9)                                                                       |
+
+There are three special values: `native`, `traditio`, and `finance`, whose meanings are locale-dependent, and will be resolved to the right system depending on the locale. Therefore, the `resolvedOptions()` methods will never return these values, but `Intl.Locale.prototype.numberingSystem` will (if provided as input).
+
+References:
+
+- [CLDR Numbering system type keys](https://github.com/unicode-org/cldr/blob/main/common/bcp47/number.xml)
+- [CLDR Numbering system definitions](https://github.com/unicode-org/cldr/blob/main/common/supplemental/numberingSystems.xml)
+- [UTS 35, Numbering systems](https://unicode.org/reports/tr35/tr35-numbers.html#Numbering_Systems)
+
+#### Supported time zone identifiers
+
+Supported time zone identifiers can be used for the `timeZone` option when creating objects such as {{jsxref("Intl.DateTimeFormat")}}, as well as for creating {{jsxref("Temporal")}} date objects. There are over 400 identifiers in common use so we won't list them. For an exhaustive list of possible identifiers, see the [Wikipedia article](https://en.wikipedia.org/wiki/List_of_tz_database_time_zones) or the [IANA time zone database](https://www.iana.org/time-zones).
+
+As you browse the list, note that the standardization of `Temporal` requires browsers to always return the primary identifier in the IANA database, which may change over time. See [time zones and offsets](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#time_zones_and_offsets) for more information. For example, the returned array should contain `"Asia/Kolkata"` instead of `"Asia/Calcutta"` because the latter is an alias of the former and they both correspond to India; however, it should contain both `"Africa/Abidjan"` and `"Atlantic/Reykjavik"` because they are in different countries, despite the latter also being an alias of the former.
+
+References:
+
+- [IANA Time Zone Database](https://www.iana.org/time-zones)
+- [UTS 35, Time Zone Identifiers](https://unicode.org/reports/tr35/tr35-dates.html#Time_Zone_Identifiers)
+
+#### Supported unit identifiers
+
+Below are all values that are commonly supported by browsers for the `unit` key. These values can be used for the `unit` option when creating objects such as {{jsxref("Intl.NumberFormat")}}. This list is a subset of the CLDR explicitly sanctioned by the ECMA-402 specification, so all implementations should be consistent.
+
+- `acre`
+- `bit`
+- `byte`
+- `celsius`
+- `centimeter`
+- `day`
+- `degree`
+- `fahrenheit`
+- `fluid-ounce`
+- `foot`
+- `gallon`
+- `gigabit`
+- `gigabyte`
+- `gram`
+- `hectare`
+- `hour`
+- `inch`
+- `kilobit`
+- `kilobyte`
+- `kilogram`
+- `kilometer`
+- `liter`
+- `megabit`
+- `megabyte`
+- `meter`
+- `microsecond`
+- `mile`
+- `mile-scandinavian`
+- `milliliter`
+- `millimeter`
+- `millisecond`
+- `minute`
+- `month`
+- `nanosecond`
+- `ounce`
+- `percent`
+- `petabyte`
+- `pound`
+- `second`
+- `stone`
+- `terabit`
+- `terabyte`
+- `week`
+- `yard`
+- `year`
+
+When specifying units, you can also combine two units with the "-per-" separator. For example, `meter-per-second` or `liter-per-megabyte`.
+
+References:
+
+- [ECMA-402 sanctioned single units](https://tc39.es/ecma402/#table-sanctioned-single-unit-identifiers)
+- [CLDR Unit validity data](https://github.com/unicode-org/cldr/blob/main/common/validity/unit.xml)
+- [UTS 35, Unit identifiers](https://unicode.org/reports/tr35/tr35-general.html#Unit_Identifiers)
 
 ### Exceptions
 
@@ -62,9 +329,6 @@ Intl.supportedValuesOf("calendar").forEach((calendar) => {
 });
 ```
 
-> [!NOTE]
-> The array returned for calendar values will always include the value "gregory" (gregorian).
-
 The other values are all obtained in the same way:
 
 ```js
diff --git a/files/en-us/web/javascript/reference/global_objects/json/index.md b/files/en-us/web/javascript/reference/global_objects/json/index.md
index c451bfb42e1d7b2..cacf30da78a9662 100644
--- a/files/en-us/web/javascript/reference/global_objects/json/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/json/index.md
@@ -240,7 +240,6 @@ const parsedData = JSON.parse(str, (key, value, context) => {
 
 ## See also
 
-- {{jsxref("Date.prototype.toJSON()")}}
 - [JSON Diff](https://json-diff.com/)
 - [JSON Beautifier/editor](https://jsonbeautifier.org/)
 - [JSON Parser](https://jsonparser.org/)
diff --git a/files/en-us/web/javascript/reference/global_objects/json/stringify/index.md b/files/en-us/web/javascript/reference/global_objects/json/stringify/index.md
index 638398fac11c1c8..5bb4cd969ee87b7 100644
--- a/files/en-us/web/javascript/reference/global_objects/json/stringify/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/json/stringify/index.md
@@ -66,7 +66,7 @@ A JSON string representing the given value, or undefined.
     - if it is in an array, the index in the array, as a string
     - if `JSON.stringify()` was directly called on this object, an empty string
 
-    {{jsxref("Date")}} objects implement the [`toJSON()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/toJSON) method which returns a string (the same as [`date.toISOString()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/toISOString)). Thus, they will be stringified as strings.
+    All {{jsxref("Temporal")}} objects implement the `toJSON()` method, which returns a string (the same as calling `toString()`). Thus, they will be serialized as strings. Similarly, {{jsxref("Date")}} objects implement `toJSON()`, which returns the same as [`toISOString()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/toISOString).
 
   - Only [enumerable own properties](/en-US/docs/Web/JavaScript/Enumerability_and_ownership_of_properties) are visited. This means {{jsxref("Map")}}, {{jsxref("Set")}}, etc. will become `"{}"`. You can use the [`replacer`](#the_replacer_parameter) parameter to serialize them to something more useful.
 
diff --git a/files/en-us/web/javascript/reference/global_objects/number/tolocalestring/index.md b/files/en-us/web/javascript/reference/global_objects/number/tolocalestring/index.md
index c58ae50259850eb..44afe9a57fb825f 100644
--- a/files/en-us/web/javascript/reference/global_objects/number/tolocalestring/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/number/tolocalestring/index.md
@@ -7,7 +7,7 @@ browser-compat: javascript.builtins.Number.toLocaleString
 
 {{JSRef}}
 
-The **`toLocaleString()`** method of {{jsxref("Number")}} values returns a string with a language-sensitive representation of this number. In implementations with [`Intl.NumberFormat` API](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/NumberFormat) support, this method simply calls `Intl.NumberFormat`.
+The **`toLocaleString()`** method of {{jsxref("Number")}} values returns a string with a language-sensitive representation of this number. In implementations with [`Intl.NumberFormat` API](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/NumberFormat) support, this method delegates to `Intl.NumberFormat`.
 
 Every time `toLocaleString` is called, it has to perform a search in a big database of localization strings, which is potentially inefficient. When the method is called many times with the same arguments, it is better to create a {{jsxref("Intl.NumberFormat")}} object and use its {{jsxref("Intl/NumberFormat/format", "format()")}} method, because a `NumberFormat` object remembers the arguments passed to it and may decide to cache a slice of the database, so future `format` calls can search for localization strings within a more constrained context.
 
diff --git a/files/en-us/web/javascript/reference/global_objects/object/tolocalestring/index.md b/files/en-us/web/javascript/reference/global_objects/object/tolocalestring/index.md
index f2a1304fd74ae4a..fdb18ba9d1fcb08 100644
--- a/files/en-us/web/javascript/reference/global_objects/object/tolocalestring/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/object/tolocalestring/index.md
@@ -19,7 +19,7 @@ toLocaleString()
 
 ### Parameters
 
-None. However, all objects that override this method are expected to accept at most two parameters, corresponding to `locales` and `options`, such as {{jsxref("Date.prototype.toLocaleString")}}. The parameter positions should not be used for any other purpose.
+None. However, all objects that override this method are expected to accept at most two parameters, corresponding to `locales` and `options`, such as {{jsxref("Number.prototype.toLocaleString")}}. The parameter positions should not be used for any other purpose.
 
 ### Return value
 
diff --git a/files/en-us/web/javascript/reference/global_objects/string/index.md b/files/en-us/web/javascript/reference/global_objects/string/index.md
index 56d8589d49050d3..2c68d8aac3ab825 100644
--- a/files/en-us/web/javascript/reference/global_objects/string/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/string/index.md
@@ -427,5 +427,5 @@ String(undefinedVar); // "undefined"
 
 ## See also
 
-- [Text formatting](/en-US/docs/Web/JavaScript/Guide/Text_formatting) guide
+- [Numbers and strings](/en-US/docs/Web/JavaScript/Guide/Numbers_and_strings) guide
 - {{jsxref("RegExp")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/string/localecompare/index.md b/files/en-us/web/javascript/reference/global_objects/string/localecompare/index.md
index 645db602eaebe59..27b77169bb6e526 100644
--- a/files/en-us/web/javascript/reference/global_objects/string/localecompare/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/string/localecompare/index.md
@@ -7,7 +7,7 @@ browser-compat: javascript.builtins.String.localeCompare
 
 {{JSRef}}
 
-The **`localeCompare()`** method of {{jsxref("String")}} values returns a number indicating whether this string comes before, or after, or is the same as the given string in sort order. In implementations with [`Intl.Collator` API](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/Collator) support, this method simply calls `Intl.Collator`.
+The **`localeCompare()`** method of {{jsxref("String")}} values returns a number indicating whether this string comes before, or after, or is the same as the given string in sort order. In implementations with [`Intl.Collator` API](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/Collator) support, this method delegates to `Intl.Collator`.
 
 When comparing large numbers of strings, such as in sorting large arrays, it is better to create an {{jsxref("Intl.Collator")}} object and use the function provided by its {{jsxref("Intl/Collator/compare", "compare()")}} method.
 
diff --git a/files/en-us/web/javascript/reference/global_objects/string/match/index.md b/files/en-us/web/javascript/reference/global_objects/string/match/index.md
index 64cf5ee76bf8f95..05b6831017bcdc8 100644
--- a/files/en-us/web/javascript/reference/global_objects/string/match/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/string/match/index.md
@@ -163,6 +163,7 @@ console.log("123".match("1\\.3")); // null
 ## See also
 
 - [Polyfill of `String.prototype.match` in `core-js` with fixes and implementation of modern behavior like `Symbol.match` support](https://github.com/zloirock/core-js#ecmascript-string-and-regexp)
+- [Regular expressions](/en-US/docs/Web/JavaScript/Guide/Regular_expressions) guide
 - {{jsxref("String.prototype.matchAll()")}}
 - {{jsxref("RegExp")}}
 - {{jsxref("RegExp.prototype.exec()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/string/matchall/index.md b/files/en-us/web/javascript/reference/global_objects/string/matchall/index.md
index fded89dbb16971b..47f16070a5d0916 100644
--- a/files/en-us/web/javascript/reference/global_objects/string/matchall/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/string/matchall/index.md
@@ -153,9 +153,9 @@ str.matchAll({
 ## See also
 
 - [Polyfill of `String.prototype.matchAll` in `core-js`](https://github.com/zloirock/core-js#ecmascript-string-and-regexp)
-- {{jsxref("String.prototype.match()")}}
 - [Regular expressions](/en-US/docs/Web/JavaScript/Guide/Regular_expressions) guide
 - [Groups and backreferences](/en-US/docs/Web/JavaScript/Guide/Regular_expressions/Groups_and_backreferences) guide
+- {{jsxref("String.prototype.match()")}}
 - {{jsxref("RegExp")}}
 - {{jsxref("RegExp.prototype.exec()")}}
 - {{jsxref("RegExp.prototype.test()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/string/replace/index.md b/files/en-us/web/javascript/reference/global_objects/string/replace/index.md
index 779abb4e4d228ef..3561a4429de9132 100644
--- a/files/en-us/web/javascript/reference/global_objects/string/replace/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/string/replace/index.md
@@ -248,6 +248,7 @@ console.log("abcd".replace(/(?<group>bc)/, addOffset)); // "abc (1) d"
 ## See also
 
 - [Polyfill of `String.prototype.replace` in `core-js` with fixes and implementation of modern behavior like `Symbol.replace` support](https://github.com/zloirock/core-js#ecmascript-string-and-regexp)
+- [Regular expressions](/en-US/docs/Web/JavaScript/Guide/Regular_expressions) guide
 - {{jsxref("String.prototype.replaceAll()")}}
 - {{jsxref("String.prototype.match()")}}
 - {{jsxref("RegExp.prototype.exec()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/string/replaceall/index.md b/files/en-us/web/javascript/reference/global_objects/string/replaceall/index.md
index 4b9aa7795b4e49e..321bbb326ebfc11 100644
--- a/files/en-us/web/javascript/reference/global_objects/string/replaceall/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/string/replaceall/index.md
@@ -104,6 +104,7 @@ This will work:
 ## See also
 
 - [Polyfill of `String.prototype.replaceAll` in `core-js`](https://github.com/zloirock/core-js#ecmascript-string-and-regexp)
+- [Regular expressions](/en-US/docs/Web/JavaScript/Guide/Regular_expressions) guide
 - {{jsxref("String.prototype.replace()")}}
 - {{jsxref("String.prototype.match()")}}
 - {{jsxref("RegExp.prototype.exec()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/string/split/index.md b/files/en-us/web/javascript/reference/global_objects/string/split/index.md
index 75991dc636d9018..8761f95edbcd4cc 100644
--- a/files/en-us/web/javascript/reference/global_objects/string/split/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/string/split/index.md
@@ -292,8 +292,8 @@ console.log(commands.split(splitCommands, 3)); // ["light on", "brightness up",
 ## See also
 
 - [Polyfill of `String.prototype.split` in `core-js` with fixes and implementation of modern behavior like `Symbol.split` support](https://github.com/zloirock/core-js#ecmascript-string-and-regexp)
+- [Regular expressions](/en-US/docs/Web/JavaScript/Guide/Regular_expressions) guide
 - {{jsxref("String.prototype.charAt()")}}
 - {{jsxref("String.prototype.indexOf()")}}
 - {{jsxref("String.prototype.lastIndexOf()")}}
 - {{jsxref("Array.prototype.join()")}}
-- [Regular expressions](/en-US/docs/Web/JavaScript/Guide/Regular_expressions) guide
diff --git a/files/en-us/web/javascript/reference/global_objects/string/string/index.md b/files/en-us/web/javascript/reference/global_objects/string/string/index.md
index 0f900eb07657af7..9d1bcce92991f2c 100644
--- a/files/en-us/web/javascript/reference/global_objects/string/string/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/string/string/index.md
@@ -77,4 +77,4 @@ String(sym); // "Symbol(example)"
 
 ## See also
 
-- [Text formatting](/en-US/docs/Web/JavaScript/Guide/Text_formatting) guide
+- [Numbers and strings](/en-US/docs/Web/JavaScript/Guide/Numbers_and_strings) guide
diff --git a/files/en-us/web/javascript/reference/global_objects/string/symbol.iterator/index.md b/files/en-us/web/javascript/reference/global_objects/string/symbol.iterator/index.md
index d2f384b14145ce8..7f655dd6753a099 100644
--- a/files/en-us/web/javascript/reference/global_objects/string/symbol.iterator/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/string/symbol.iterator/index.md
@@ -84,6 +84,6 @@ console.log(strIter.next().value); // "\uD835\uDC68"
 ## See also
 
 - [Polyfill of `String.prototype[Symbol.iterator]` in `core-js`](https://github.com/zloirock/core-js#ecmascript-string-and-regexp)
-- [Text formatting](/en-US/docs/Web/JavaScript/Guide/Text_formatting) guide
+- [Numbers and strings](/en-US/docs/Web/JavaScript/Guide/Numbers_and_strings) guide
 - {{jsxref("Symbol.iterator")}}
 - [Iteration protocols](/en-US/docs/Web/JavaScript/Reference/Iteration_protocols)
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/duration/abs/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/duration/abs/index.md
new file mode 100644
index 000000000000000..c5118b62162b39f
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/duration/abs/index.md
@@ -0,0 +1,52 @@
+---
+title: Temporal.Duration.prototype.abs()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Duration/abs
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Duration.abs
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`abs()`** method of {{jsxref("Temporal.Duration")}} instances returns a new `Temporal.Duration` object with the absolute value of this duration (all fields have the same magnitude, but sign becomes positive).
+
+## Syntax
+
+```js-nolint
+abs()
+```
+
+### Parameters
+
+None.
+
+### Return value
+
+A new `Temporal.Duration` object with the absolute value of this duration, which is either the same as this duration if it is already positive, or its [negation](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration/negated) if it is negative.
+
+## Examples
+
+### Using abs()
+
+```js
+const d1 = Temporal.Duration.from({ hours: 1, minutes: 30 });
+const d2 = Temporal.Duration.from({ hours: -1, minutes: -30 });
+
+console.log(d1.abs().toString()); // "PT1H30M"
+console.log(d2.abs().toString()); // "PT1H30M"
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/Duration/negated", "Temporal.Duration.prototype.negated()")}}
+- {{jsxref("Temporal/Duration/sign", "Temporal.Duration.prototype.sign")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/duration/add/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/duration/add/index.md
new file mode 100644
index 000000000000000..58cec601cb81dec
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/duration/add/index.md
@@ -0,0 +1,80 @@
+---
+title: Temporal.Duration.prototype.add()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Duration/add
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Duration.add
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`add()`** method of {{jsxref("Temporal.Duration")}} instances returns a new `Temporal.Duration` object with the sum of this duration and a given duration. The result is [balanced](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#duration_balancing).
+
+## Syntax
+
+```js-nolint
+add(other)
+```
+
+### Parameters
+
+- `other`
+  - : A string, an object, or a {{jsxref("Temporal.Duration")}} instance representing a duration to add to this duration. It is converted to a `Temporal.Duration` object using the same algorithm as {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}.
+
+### Return value
+
+A new `Temporal.Duration` object representing the sum of this duration and `other`.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown in one of the following cases:
+    - Either `this` or `other` is a [calendar duration](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#calendar_durations) (it has a non-zero `years`, `months`, or `weeks`), because calendar durations are ambiguous without a calendar and time reference.
+    - The sum of `this` and `other` overflows the maximum or underflows the minimum representable duration, which is ±2<sup>53</sup> seconds.
+
+## Description
+
+Non-calendar durations unambiguously represent a fixed amount of time. Internally, `this` and `other` are both converted to nanoseconds (assuming 24-hour days) and added together. The result is then converted back to a `Temporal.Duration` object, so the result is always [balanced](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#duration_balancing) with the largest possible unit being `days`.
+
+If you want to perform addition or subtraction with a calendar duration, you can add both durations to a starting point and then figure out the difference between the two resulting instants; that is, `dur1 + dur2` is equivalent to `(start + dur1 + dur2) - start`.
+
+To add a duration to a date or time, use the `add()` method of the date or time object instead.
+
+## Examples
+
+### Using add()
+
+```js
+const d1 = Temporal.Duration.from({ hours: 1, minutes: 30 });
+const d2 = Temporal.Duration.from({ hours: -1, minutes: -20 });
+
+const d3 = d1.add(d2);
+console.log(d3.toString()); // "PT10M"
+```
+
+### Adding calendar durations
+
+```js
+const d1 = Temporal.Duration.from({ days: 1 });
+const d2 = Temporal.Duration.from({ months: 1 });
+
+d1.add(d2); // RangeError: can't compare durations when "relativeTo" is undefined
+
+const start = Temporal.PlainDateTime.from("2022-01-01T00:00"); // ISO 8601 calendar
+const result = start.add(d1).add(d2).since(start);
+console.log(result.toString()); // "P32D"
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/Duration/subtract", "Temporal.Duration.prototype.subtract()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/duration/blank/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/duration/blank/index.md
new file mode 100644
index 000000000000000..118a83dc8e8b891
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/duration/blank/index.md
@@ -0,0 +1,39 @@
+---
+title: Temporal.Duration.prototype.blank
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Duration/blank
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Duration.blank
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`blank`** accessor property of {{jsxref("Temporal.Duration")}} instances returns a boolean that is `true` if this duration represents a zero duration, and `false` otherwise. It is equivalent to `duration.sign === 0`.
+
+## Examples
+
+### Using blank
+
+```js
+const d1 = Temporal.Duration.from({ hours: 1, minutes: 30 });
+const d2 = Temporal.Duration.from({ hours: -1, minutes: -30 });
+const d3 = Temporal.Duration.from({ hours: 0 });
+
+console.log(d1.blank); // false
+console.log(d2.blank); // false
+console.log(d3.blank); // true
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/Duration/sign", "Temporal.Duration.prototype.sign")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/duration/compare/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/duration/compare/index.md
new file mode 100644
index 000000000000000..b0fddc0fcfd378c
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/duration/compare/index.md
@@ -0,0 +1,137 @@
+---
+title: Temporal.Duration.compare()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Duration/compare
+page-type: javascript-static-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Duration.compare
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.Duration.compare()`** static method returns a number (-1, 0, or 1) indicating whether the first duration is shorter, equal to, or longer than the second duration.
+
+## Syntax
+
+```js-nolint
+Temporal.Duration.compare(duration1, duration2)
+Temporal.Duration.compare(duration1, duration2, options)
+```
+
+### Parameters
+
+- `duration1`
+  - : A string, an object, or a {{jsxref("Temporal.Duration")}} instance representing the first duration to compare. It is converted to a `Temporal.Duration` object using the same algorithm as {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}.
+- `duration2`
+  - : The second duration to compare, converted to a `Temporal.Duration` object using the same algorithm as `duration1`.
+- `options` {{optional_inline}}
+  - : An object containing the following property:
+    - `relativeTo` {{optional_inline}}
+      - : A zoned or plain date(time) that provides the time and calendar information to resolve [calendar durations](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#calendar_durations) (see the link for the general interpretation of this option). Required if either `duration1` or `duration2` is a calendar duration (unless they are equal component-wise, in which case `0` is returned without computations).
+
+### Return value
+
+Returns `-1` if `duration1` is shorter than `duration2`, `0` if they are equal, and `1` if `duration1` is longer.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown if either `duration1` or `duration2` is a [calendar duration](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#calendar_durations) (it has a non-zero `years`, `months`, or `weeks`), and `relativeTo` is not provided.
+
+## Description
+
+If `relativeTo` is a zoned date-time, and either `duration1` or `duration2` is a calendar duration, the result is calculated by adding the durations to the starting point, and then comparing the resulting instants. Otherwise, the comparison is done by converting both of them to nanoseconds (assuming 24-hour days, and using the calendar of `relativeTo` if necessary) and comparing the results.
+
+## Examples
+
+### Using Temporal.Duration.compare()
+
+```js
+const d1 = Temporal.Duration.from({ hours: 1, minutes: 30 });
+const d2 = Temporal.Duration.from({ minutes: 100 });
+console.log(Temporal.Duration.compare(d1, d2)); // -1
+
+const d3 = Temporal.Duration.from({ hours: 2 });
+const d4 = Temporal.Duration.from({ minutes: 110 });
+console.log(Temporal.Duration.compare(d3, d4)); // 1
+
+const d5 = Temporal.Duration.from({ hours: 1, minutes: 30 });
+const d6 = Temporal.Duration.from({ seconds: 5400 });
+console.log(Temporal.Duration.compare(d5, d6)); // 0
+```
+
+### Comparing calendar durations
+
+```js
+const d1 = Temporal.Duration.from({ days: 31 });
+const d2 = Temporal.Duration.from({ months: 1 });
+
+console.log(
+  Temporal.Duration.compare(d1, d2, {
+    relativeTo: Temporal.PlainDate.from("2021-01-01"), // ISO 8601 calendar
+  }),
+); // 0
+
+console.log(
+  Temporal.Duration.compare(d1, d2, {
+    relativeTo: Temporal.PlainDate.from("2021-02-01"), // ISO 8601 calendar
+  }),
+); // 1; February has 28 days
+```
+
+### Using zoned relativeTo
+
+Using a zoned `relativeTo`, you can even take into account daylight saving time changes. On `2024-11-03`, the US shifts from daylight saving time to standard time, so that day has 25 hours because the clock is set back by 1 hour.
+
+```js
+const d1 = Temporal.Duration.from({ days: 1 });
+const d2 = Temporal.Duration.from({ hours: 24 });
+
+console.log(
+  Temporal.Duration.compare(d1, d2, {
+    relativeTo: Temporal.ZonedDateTime.from(
+      "2024-11-03T01:00-04:00[America/New_York]",
+    ),
+  }),
+); // 1
+```
+
+### Sorting an array of durations
+
+The purpose of this `compare()` function is to act as a comparator to be passed to {{jsxref("Array.prototype.sort()")}} and related functions.
+
+```js
+const durations = [
+  Temporal.Duration.from({ hours: 1 }),
+  Temporal.Duration.from({ hours: 2 }),
+  Temporal.Duration.from({ hours: 1, minutes: 30 }),
+  Temporal.Duration.from({ hours: 1, minutes: 45 }),
+];
+
+durations.sort(Temporal.Duration.compare);
+console.log(durations.map((d) => d.toString()));
+// [ 'PT1H', 'PT1H30M', 'PT1H45M', 'PT2H' ]
+```
+
+Pass options like this:
+
+```js
+durations.sort((a, b) =>
+  Temporal.Duration.compare(a, b, {
+    relativeTo: Temporal.Now.zonedDateTimeISO(),
+  }),
+);
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/Duration/subtract", "Temporal.Duration.prototype.subtract()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/duration/days/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/duration/days/index.md
new file mode 100644
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--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/duration/days/index.md
@@ -0,0 +1,61 @@
+---
+title: Temporal.Duration.prototype.days
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Duration/days
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Duration.days
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`days`** accessor property of {{jsxref("Temporal.Duration")}} instances returns an integer representing the number of days in the duration.
+
+Unless the duration is [balanced](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#duration_balancing), you cannot assume the range of this value, but you can know its sign by checking the duration's [`sign`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration/sign) property. If it is balanced to a unit above days, the `days` absolute value's range depends on the calendar (how many days are in a week or month).
+
+The set accessor of `days` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/Duration/with", "with()")}} method to create a new `Temporal.Duration` object with the desired new value.
+
+## Examples
+
+### Using days
+
+```js
+const d1 = Temporal.Duration.from({ weeks: 1, days: 1 });
+const d2 = Temporal.Duration.from({ weeks: -1, days: -1 });
+const d3 = Temporal.Duration.from({ weeks: 1 });
+const d4 = Temporal.Duration.from({ days: 7 });
+
+console.log(d1.days); // 1
+console.log(d2.days); // -1
+console.log(d3.days); // 0
+console.log(d4.days); // 7
+
+// Balance d4
+const d4Balanced = d4.round({
+  largestUnit: "week",
+  relativeTo: Temporal.PlainDate.from("2021-01-01"), // ISO 8601 calendar
+});
+console.log(d4Balanced.days); // 0
+console.log(d4Balanced.weeks); // 1
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/Duration/years", "Temporal.Duration.prototype.years")}}
+- {{jsxref("Temporal/Duration/months", "Temporal.Duration.prototype.months")}}
+- {{jsxref("Temporal/Duration/weeks", "Temporal.Duration.prototype.weeks")}}
+- {{jsxref("Temporal/Duration/hours", "Temporal.Duration.prototype.hours")}}
+- {{jsxref("Temporal/Duration/minutes", "Temporal.Duration.prototype.minutes")}}
+- {{jsxref("Temporal/Duration/seconds", "Temporal.Duration.prototype.seconds")}}
+- {{jsxref("Temporal/Duration/milliseconds", "Temporal.Duration.prototype.milliseconds")}}
+- {{jsxref("Temporal/Duration/microseconds", "Temporal.Duration.prototype.microseconds")}}
+- {{jsxref("Temporal/Duration/nanoseconds", "Temporal.Duration.prototype.nanoseconds")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/duration/duration/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/duration/duration/index.md
new file mode 100644
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--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/duration/duration/index.md
@@ -0,0 +1,89 @@
+---
+title: Temporal.Duration()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Duration/Duration
+page-type: javascript-constructor
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Duration.Duration
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.Duration()`** constructor creates {{jsxref("Temporal.Duration")}} objects.
+
+This constructor allows you to create instances by directly supplying the underlying data. Like all other `Temporal` classes, you should usually construct `Temporal.Duration` objects using the {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}} static method, which can handle a variety of input types.
+
+## Syntax
+
+```js-nolint
+new Temporal.Duration()
+new Temporal.Duration(years)
+new Temporal.Duration(years, months)
+new Temporal.Duration(years, months, weeks)
+new Temporal.Duration(years, months, weeks, days)
+new Temporal.Duration(years, months, weeks, days, hours)
+new Temporal.Duration(years, months, weeks, days, hours, minutes)
+new Temporal.Duration(years, months, weeks, days, hours, minutes, seconds)
+new Temporal.Duration(years, months, weeks, days, hours, minutes, seconds, milliseconds)
+new Temporal.Duration(years, months, weeks, days, hours, minutes, seconds, milliseconds, microseconds)
+new Temporal.Duration(years, months, weeks, days, hours, minutes, seconds, milliseconds, microseconds, nanoseconds)
+```
+
+> **Note:** `Temporal.Duration()` can only be constructed with [`new`](/en-US/docs/Web/JavaScript/Reference/Operators/new). Attempting to call it without `new` throws a {{jsxref("TypeError")}}.
+
+### Parameters
+
+- `years` {{optional_inline}}
+  - : Number of years, or `undefined` (which is treated as `0`).
+- `months` {{optional_inline}}
+  - : Number of months, or `undefined` (which is treated as `0`).
+- `weeks` {{optional_inline}}
+  - : Number of weeks, or `undefined` (which is treated as `0`).
+- `days` {{optional_inline}}
+  - : Number of days, or `undefined` (which is treated as `0`).
+- `hours` {{optional_inline}}
+  - : Number of hours, or `undefined` (which is treated as `0`).
+- `minutes` {{optional_inline}}
+  - : Number of minutes, or `undefined` (which is treated as `0`).
+- `seconds` {{optional_inline}}
+  - : Number of seconds, or `undefined` (which is treated as `0`).
+- `milliseconds` {{optional_inline}}
+  - : Number of milliseconds, or `undefined` (which is treated as `0`).
+- `microseconds` {{optional_inline}}
+  - : Number of microseconds, or `undefined` (which is treated as `0`).
+- `nanoseconds` {{optional_inline}}
+  - : Number of nanoseconds, or `undefined` (which is treated as `0`).
+
+### Return value
+
+A new `Temporal.Duration` object, possibly [unbalanced](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#duration_balancing), with the specified components.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown in one of the following cases:
+    - Any of the parameters is not an integer (including non-finite values).
+    - A [calendar unit](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#calendar_durations) (years, months, weeks) has an absolute value ≥ 2<sup>32</sup>.
+    - The non-calendar part of the duration (days and below), when expressed in seconds, has an absolute value ≥ 2<sup>53</sup>.
+
+## Examples
+
+### Using Temporal.Duration()
+
+```js
+const d = new Temporal.Duration(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
+console.log(d.toString()); // "P1Y2M3W4DT5H6M7.00800901S"
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/duration/from/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/duration/from/index.md
new file mode 100644
index 000000000000000..08e0a1975b0ff3f
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/duration/from/index.md
@@ -0,0 +1,109 @@
+---
+title: Temporal.Duration.from()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Duration/from
+page-type: javascript-static-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Duration.from
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.Duration.from()`** static method creates a new `Temporal.Duration` object from another `Temporal.Duration` object, an object with duration properties, or an ISO 8601 string.
+
+## Syntax
+
+```js-nolint
+Temporal.Duration.from(info)
+```
+
+### Parameters
+
+- `info`
+
+  - : One of the following:
+
+    - A {{jsxref("Temporal.Duration")}} instance, which creates a copy of the instance.
+    - An [ISO 8601](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#iso_8601_duration_format) string representing a duration.
+    - An object containing at least one of the following properties (in the order they are retrieved and validated):
+
+      - {{jsxref("Temporal/Duration/days", "days")}}
+      - {{jsxref("Temporal/Duration/hours", "hours")}}
+      - {{jsxref("Temporal/Duration/microseconds", "microseconds")}}
+      - {{jsxref("Temporal/Duration/milliseconds", "milliseconds")}}
+      - {{jsxref("Temporal/Duration/minutes", "minutes")}}
+      - {{jsxref("Temporal/Duration/months", "months")}}
+      - {{jsxref("Temporal/Duration/nanoseconds", "nanoseconds")}}
+      - {{jsxref("Temporal/Duration/seconds", "seconds")}}
+      - {{jsxref("Temporal/Duration/weeks", "weeks")}}
+      - {{jsxref("Temporal/Duration/years", "years")}}
+
+      Each property should contain an integer number value. The resulting duration must not have [mixed signs](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#duration_sign), so all of these properties must have the same sign (or zero). Missing properties are treated as zero.
+
+### Return value
+
+A new `Temporal.Duration` object, possibly [unbalanced](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#duration_balancing), with the specified components.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown in one of the following cases:
+    - Any of the recognized properties in the `info` object is not an integer (including non-finite values).
+    - A [calendar unit](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#calendar_durations) (years, months, weeks) has an absolute value ≥ 2<sup>32</sup>.
+    - The non-calendar part of the duration (days and below), when expressed in seconds, has an absolute value ≥ 2<sup>53</sup>.
+- {{jsxref("TypeError")}}
+  - : Thrown in one of the following cases:
+    - `info` is not an object or a string.
+    - All of the recognized properties in the `info` object are `undefined`.
+
+## Examples
+
+### Creating a duration from an object
+
+```js
+const d1 = Temporal.Duration.from({ hours: 1, minutes: 30 });
+console.log(d1.toString()); // "PT1H30M"
+
+const d2 = Temporal.Duration.from({ months: 1, days: 2 });
+console.log(d2.toString()); // "P1M2D"
+
+// Uncommon because unbalanced, but valid
+const unbalanced = Temporal.Duration.from({
+  hours: 100,
+  minutes: 100,
+  seconds: 100,
+});
+console.log(unbalanced.toString()); // "PT100H100M100S"
+
+const neg = Temporal.Duration.from({ hours: -1, minutes: -30 });
+console.log(neg.toString()); // "-PT1H30M"
+```
+
+### Creating a duration from a string
+
+```js
+const d = Temporal.Duration.from("P1Y2M3W4DT5H6M7.00800901S");
+console.log(d.hours); // 5
+```
+
+### Creating a duration from another duration
+
+```js
+const d1 = Temporal.Duration.from({ hours: 1, minutes: 30 });
+const d2 = Temporal.Duration.from(d1);
+console.log(d2.toString()); // "PT1H30M"
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/Duration/Duration", "Temporal.Duration()")}}
+- {{jsxref("Temporal/Duration/with", "Temporal.Duration.prototype.with()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/duration/hours/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/duration/hours/index.md
new file mode 100644
index 000000000000000..6875629f1b47b61
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/duration/hours/index.md
@@ -0,0 +1,58 @@
+---
+title: Temporal.Duration.prototype.hours
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Duration/hours
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Duration.hours
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`hours`** accessor property of {{jsxref("Temporal.Duration")}} instances returns an integer representing the number of hours in the duration.
+
+Unless the duration is [balanced](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#duration_balancing), you cannot assume the range of this value, but you can know its sign by checking the duration's [`sign`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration/sign) property. If it is balanced to a unit above hours, the `hours` absolute value will be between 0 and 23, inclusive.
+
+The set accessor of `hours` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/Duration/with", "with()")}} method to create a new `Temporal.Duration` object with the desired new value.
+
+## Examples
+
+### Using hours
+
+```js
+const d1 = Temporal.Duration.from({ hours: 1, minutes: 30 });
+const d2 = Temporal.Duration.from({ hours: -1, minutes: -30 });
+const d3 = Temporal.Duration.from({ days: 1 });
+const d4 = Temporal.Duration.from({ hours: 24 });
+
+console.log(d1.hours); // 1
+console.log(d2.hours); // -1
+console.log(d3.hours); // 0
+console.log(d4.hours); // 24
+
+// Balance d4
+const d4Balanced = d4.round({ largestUnit: "day" });
+console.log(d4Balanced.hours); // 0
+console.log(d4Balanced.days); // 1
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/Duration/years", "Temporal.Duration.prototype.years")}}
+- {{jsxref("Temporal/Duration/months", "Temporal.Duration.prototype.months")}}
+- {{jsxref("Temporal/Duration/weeks", "Temporal.Duration.prototype.weeks")}}
+- {{jsxref("Temporal/Duration/days", "Temporal.Duration.prototype.days")}}
+- {{jsxref("Temporal/Duration/minutes", "Temporal.Duration.prototype.minutes")}}
+- {{jsxref("Temporal/Duration/seconds", "Temporal.Duration.prototype.seconds")}}
+- {{jsxref("Temporal/Duration/milliseconds", "Temporal.Duration.prototype.milliseconds")}}
+- {{jsxref("Temporal/Duration/microseconds", "Temporal.Duration.prototype.microseconds")}}
+- {{jsxref("Temporal/Duration/nanoseconds", "Temporal.Duration.prototype.nanoseconds")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/duration/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/duration/index.md
new file mode 100644
index 000000000000000..5cc6f19be94e190
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/duration/index.md
@@ -0,0 +1,165 @@
+---
+title: Temporal.Duration
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Duration
+page-type: javascript-class
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Duration
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.Duration`** object represents a difference between two time points, which can be used in date/time arithmetic. It is fundamentally represented as a combination of years, months, weeks, days, hours, minutes, seconds, milliseconds, microseconds, and nanoseconds values.
+
+## Description
+
+### ISO 8601 duration format
+
+`Duration` objects can be serialized and parsed using the [ISO 8601 duration format](https://en.wikipedia.org/wiki/ISO_8601#Durations) (with some extensions specified by ECMAScript). The string has the following form (spaces are only for readability and should not be present in the actual string):
+
+```plain
+±P nY nM nW nD T nH nM nS
+```
+
+- `±` {{optional_inline}}
+  - : An optional sign character (`+` or `-`), which represents positive or negative duration. Default is positive.
+- `P`
+  - : A literal character `P` or `p` that stands for "period".
+- `nY`, `nM`, `nW`, `nD`, `nH`, `nM`, `nS`
+  - : A number followed by a literal character, which represents the number of years (`Y`), months (`M`), weeks (`W`), days (`D`), hours (`H`), minutes (`M`), or seconds (`S`), respectively. All except the last existing component must be an integer. The last component, if it is a time component (hours, minutes, or seconds), may have a fractional part of 1 to 9 digits, led by a dot or a comma, such as `PT0.0021S` or `PT1.1H`. Any zero components may be omitted, but at least one component should be present (even if it has value zero, in which case the duration is zero).
+- `T`
+  - : A literal character `T` or `t` that separates the date part from the time part, which should be present if and only if there's at least one component after it.
+
+Here are some examples:
+
+| ISO 8601           | Meaning                                                                  |
+| ------------------ | ------------------------------------------------------------------------ |
+| `P1Y1M1DT1H1M1.1S` | 1 year, 1 month, 1 day, 1 hour, 1 minute, 1 second, and 100 milliseconds |
+| `P40D`             | 40 days                                                                  |
+| `P1Y1D`            | 1 year and 1 day                                                         |
+| `P3DT4H59M`        | 3 days, 4 hours and 59 minutes                                           |
+| `PT2H30M`          | 2 hours and 30 minutes                                                   |
+| `P1M`              | 1 month                                                                  |
+| `PT1M`             | 1 minute                                                                 |
+| `PT0.0021S`        | 2.1 milliseconds (2 milliseconds and 100 microseconds)                   |
+| `PT0S`             | Zero (canonical representation)                                          |
+| `P0D`              | Zero                                                                     |
+
+> [!NOTE]
+> According to the ISO 8601-1 standard, weeks are not allowed to appear together with any other units, and durations can only be positive. As extensions to the standard, ISO 8601-2, which Temporal uses, allows a sign character at the start of the string, and allows combining weeks with other units. Therefore, if your duration is serialized to a string like `P3W1D`, `+P1M`, or `-P1M`, note that other programs may not accept it.
+
+When serializing, the output respects the stored components as much as possible, preserving [unbalanced](#duration_balancing) components. However, subsecond components are serialized as a single fractional second, so their precise values, if unbalanced may be lost. The plus sign is omitted for positive durations. The zero duration is always serialized as `PT0S`.
+
+### Calendar durations
+
+A _calendar duration_ is one that contains any of the [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars) units: weeks, months, and years. A non-calendar duration is portable and can participate in date/time arithmetic without any calendar information, because they unambiguously represent a fixed amount of time. However, a calendar duration is not portable because the number of days in a month or year depends on the calendar system and the reference time point. Therefore, attempting to perform any arithmetic operation on a calendar durations throws an error because durations don't keep track of a calendar themselves. For example, if we are in May of the Gregorian calendar, then "1 month" is "31 days", but if we are in April, then "1 month" becomes "30 days". To add or subtract calendar durations, you need to add them to dates instead:
+
+```js
+const dur1 = Temporal.Duration.from({ years: 1 });
+const dur2 = Temporal.Duration.from({ months: 1 });
+
+dur1.add(dur2); // RangeError: can't compare durations when "relativeTo" is undefined
+
+const startingPoint = Temporal.PlainDate.from("2021-01-01"); // ISO 8601 calendar
+startingPoint.add(dur1).add(dur2).since(startingPoint); // "P396D"
+```
+
+Other operations, including `round()`, `total()`, and `compare()`, take a `relativeTo` option to provide the necessary calendar and reference time information. This option can be a {{jsxref("Temporal.PlainDate")}}, {{jsxref("Temporal.PlainDateTime")}}, {{jsxref("Temporal.ZonedDateTime")}}, or otherwise an object or string that's convertible using {{jsxref("Temporal/ZonedDateTime/from", "Temporal.ZonedDateTime.from()")}} (if the `timeZone` option is provided or the string contains time zone annotation) or {{jsxref("Temporal/PlainDateTime/from", "Temporal.PlainDateTime.from()")}}.
+
+Note that `days` to `hours` conversion is also technically ambiguous because the length of a day may vary due to offset changes, such as daylight saving time. You can provide a zoned `relativeTo` to account for these changes; otherwise 24-hour days are assumed.
+
+### Duration balancing
+
+There are many ways to represent the same duration: for example, "1 minute and 30 seconds" and "90 seconds" are equivalent. However, depending on the context, one representation may be more appropriate than the other. Therefore, generally, the `Duration` object preserves the input values as much as possible, so that when you format it, it will be displayed as you expect.
+
+Each component of a duration has its optimal range; hours should be from 0 to 23, minutes from 0 to 59, and so on. When a component overflows its optimal range, the excess may be "carried" into the next larger component. To carry over, we need to answer the question of "how many X are in a Y?", which is a complicated question for [calendar units](#calendar_durations), so in this case a calendar is needed. Also note that by default, `days` are directly carried into `months`; the weeks unit is only carried into if explicitly requested. If we carry as much as possible, the eventual result where all components are within their optimal range is called a "balanced" duration. Unbalanced durations usually come in the "top-heavy" form, where the largest unit is unbalanced (e.g., "27 hours and 30 minutes"); other forms, such as "23 hours and 270 minutes", are rarely seen.
+
+The {{jsxref("Temporal/Duration/round", "round()")}} method always balances the duration into the "top-heavy" form, up to the `largestUnit` option. With a manual `largestUnit` option that's large enough, you can fully balance the duration. Similarly, the {{jsxref("Temporal/Duration/add", "add()")}} and {{jsxref("Temporal/Duration/subtract", "subtract()")}} methods balance the result duration to the largest unit of the input durations.
+
+Note that because the ISO 8601 duration format represents subsecond components as one single fraction number, it is not possible to preserve unbalanced subsecond components during serialization using the default format. For example, "1000 milliseconds" is serialized as `"PT1S"`, and then deserialized as "1 second". If you need to preserve the subsecond components' magnitudes, you need to manually serialize it as a JSON object instead (because by default the {{jsxref("Temporal/Duration/toJSON", "toJSON()")}} method serializes the duration in the ISO 8601 format).
+
+### Duration sign
+
+Because a duration is a difference between two time points, it can be positive, negative, or zero. For example, if you are displaying event times in relative time, then negative durations may represent events in the past, and positive durations for the future. In our representation using a combination of time components, the sign is stored within each component: a negative duration always has all components negative (or zero), and a positive duration always has all components positive (or zero). Constructing a duration with components of mixed signs is invalid and will be rejected by the constructor or the {{jsxref("Temporal/Duration/with", "with()")}} method. The `add()` and `subtract()` methods will balance the result duration to avoid mixed signs.
+
+## Constructor
+
+- {{jsxref("Temporal/Duration/Duration", "Temporal.Duration()")}} {{experimental_inline}}
+  - : Creates a new `Temporal.Duration` object by directly supplying the underlying data.
+
+## Static methods
+
+- {{jsxref("Temporal/Duration/compare", "Temporal.Duration.compare()")}} {{experimental_inline}}
+  - : Returns a number (-1, 0, or 1) indicating whether the first duration is shorter, equal to, or longer than the second duration.
+- {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}} {{experimental_inline}}
+  - : Creates a new `Temporal.Duration` object from another `Temporal.Duration` object, an object with duration properties, or an ISO 8601 string.
+
+## Instance properties
+
+These properties are defined on `Temporal.Duration.prototype` and shared by all `Temporal.Duration` instances.
+
+- {{jsxref("Temporal/Duration/blank", "Temporal.Duration.prototype.blank")}} {{experimental_inline}}
+  - : Returns a boolean that is `true` if this duration represents a zero duration, and `false` otherwise. Equivalent to `duration.sign === 0`.
+- {{jsxref("Object/constructor", "Temporal.Duration.prototype.constructor")}}
+  - : The constructor function that created the instance object. For `Temporal.Duration` instances, the initial value is the {{jsxref("Temporal/Duration/Duration", "Temporal.Duration()")}} constructor.
+- {{jsxref("Temporal/Duration/days", "Temporal.Duration.prototype.days")}} {{experimental_inline}}
+  - : Returns an integer representing the number of days in the duration.
+- {{jsxref("Temporal/Duration/hours", "Temporal.Duration.prototype.hours")}} {{experimental_inline}}
+  - : Returns an integer representing the number of hours in the duration.
+- {{jsxref("Temporal/Duration/microseconds", "Temporal.Duration.prototype.microseconds")}} {{experimental_inline}}
+  - : Returns an integer representing the number of microseconds in the duration.
+- {{jsxref("Temporal/Duration/milliseconds", "Temporal.Duration.prototype.milliseconds")}} {{experimental_inline}}
+  - : Returns an integer representing the number of milliseconds in the duration.
+- {{jsxref("Temporal/Duration/minutes", "Temporal.Duration.prototype.minutes")}} {{experimental_inline}}
+  - : Returns an integer representing the number of minutes in the duration.
+- {{jsxref("Temporal/Duration/months", "Temporal.Duration.prototype.months")}} {{experimental_inline}}
+  - : Returns an integer representing the number of months in the duration.
+- {{jsxref("Temporal/Duration/nanoseconds", "Temporal.Duration.prototype.nanoseconds")}} {{experimental_inline}}
+  - : Returns an integer representing the number of nanoseconds in the duration.
+- {{jsxref("Temporal/Duration/seconds", "Temporal.Duration.prototype.seconds")}} {{experimental_inline}}
+  - : Returns an integer representing the number of seconds in the duration.
+- {{jsxref("Temporal/Duration/sign", "Temporal.Duration.prototype.sign")}} {{experimental_inline}}
+  - : Returns `1` if this duration is positive, `-1` if negative, and `0` if zero.
+- {{jsxref("Temporal/Duration/weeks", "Temporal.Duration.prototype.weeks")}} {{experimental_inline}}
+  - : Returns an integer representing the number of weeks in the duration.
+- {{jsxref("Temporal/Duration/years", "Temporal.Duration.prototype.years")}} {{experimental_inline}}
+  - : Returns an integer representing the number of years in the duration.
+- `Temporal.Duration.prototype[Symbol.toStringTag]`
+  - : The initial value of the [`[Symbol.toStringTag]`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol/toStringTag) property is the string `"Temporal.Duration"`. This property is used in {{jsxref("Object.prototype.toString()")}}.
+
+## Instance methods
+
+- {{jsxref("Temporal/Duration/abs", "Temporal.Duration.prototype.abs()")}} {{experimental_inline}}
+  - : Returns a new `Temporal.Duration` object with the absolute value of this duration (all fields keep the same magnitude, but sign becomes positive).
+- {{jsxref("Temporal/Duration/add", "Temporal.Duration.prototype.add()")}} {{experimental_inline}}
+  - : Returns a new `Temporal.Duration` object with the sum of this duration and a given duration (in a form convertible by {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}). The result is [balanced](#duration_balancing).
+- {{jsxref("Temporal/Duration/negated", "Temporal.Duration.prototype.negated()")}} {{experimental_inline}}
+  - : Returns a new `Temporal.Duration` object with the negated value of this duration (all fields keep the same magnitude, but sign becomes reversed).
+- {{jsxref("Temporal/Duration/round", "Temporal.Duration.prototype.round()")}} {{experimental_inline}}
+  - : Returns a new `Temporal.Duration` object with the duration rounded to the given smallest unit and/or [balanced](#duration_balancing) to the given largest unit.
+- {{jsxref("Temporal/Duration/subtract", "Temporal.Duration.prototype.subtract()")}} {{experimental_inline}}
+  - : Returns a new `Temporal.Duration` object with the difference between this duration and a given duration (in a form convertible by {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}). Equivalent to [adding](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration/add) the [negated](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration/negated) value of the other duration.
+- {{jsxref("Temporal/Duration/toJSON", "Temporal.Duration.prototype.toJSON()")}} {{experimental_inline}}
+  - : Returns a string representing this duration in the same [ISO 8601 format](#iso_8601_duration_format) as calling {{jsxref("Temporal/Duration/toString", "toString()")}}. Intended to be implicitly called by {{jsxref("JSON.stringify()")}}.
+- {{jsxref("Temporal/Duration/toLocaleString", "Temporal.Duration.prototype.toLocaleString()")}} {{experimental_inline}}
+  - : Returns a string with a language-sensitive representation of this duration. In implementations with [`Intl.DurationFormat` API](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DurationFormat) support, this method delegates to `Intl.DurationFormat`.
+- {{jsxref("Temporal/Duration/toString", "Temporal.Duration.prototype.toString()")}} {{experimental_inline}}
+  - : Returns a string representing this duration in the [ISO 8601 format](#iso_8601_duration_format).
+- {{jsxref("Temporal/Duration/total", "Temporal.Duration.prototype.total()")}} {{experimental_inline}}
+  - : Returns a number representing the total duration in the given unit.
+- {{jsxref("Temporal/Duration/valueOf", "Temporal.Duration.prototype.valueOf()")}} {{experimental_inline}}
+  - : Throws a {{jsxref("TypeError")}}, which prevents `Temporal.Duration` instances from being [implicitly converted to primitives](/en-US/docs/Web/JavaScript/Data_structures#primitive_coercion) when used in arithmetic or comparison operations.
+- {{jsxref("Temporal/Duration/with", "Temporal.Duration.prototype.with()")}} {{experimental_inline}}
+  - : Returns a new `Temporal.Duration` object representing this duration with some fields replaced by new values.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/duration/microseconds/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/duration/microseconds/index.md
new file mode 100644
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--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/duration/microseconds/index.md
@@ -0,0 +1,58 @@
+---
+title: Temporal.Duration.prototype.microseconds
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Duration/microseconds
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Duration.microseconds
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`microseconds`** accessor property of {{jsxref("Temporal.Duration")}} instances returns an integer representing the number of microseconds in the duration.
+
+Unless the duration is [balanced](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#duration_balancing), you cannot assume the range of this value, but you can know its sign by checking the duration's [`sign`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration/sign) property. If it is balanced to a unit above microseconds, the `microseconds` absolute value will be between 0 and 999, inclusive.
+
+The set accessor of `microseconds` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/Duration/with", "with()")}} method to create a new `Temporal.Duration` object with the desired new value.
+
+## Examples
+
+### Using microseconds
+
+```js
+const d1 = Temporal.Duration.from({ milliseconds: 1, microseconds: 500 });
+const d2 = Temporal.Duration.from({ milliseconds: -1, microseconds: -500 });
+const d3 = Temporal.Duration.from({ milliseconds: 1 });
+const d4 = Temporal.Duration.from({ microseconds: 1000 });
+
+console.log(d1.microseconds); // 500
+console.log(d2.microseconds); // -500
+console.log(d3.microseconds); // 0
+console.log(d4.microseconds); // 1000
+
+// Balance d4
+const d4Balanced = d4.round({ largestUnit: "millisecond" });
+console.log(d4Balanced.microseconds); // 0
+console.log(d4Balanced.milliseconds); // 1
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/Duration/years", "Temporal.Duration.prototype.years")}}
+- {{jsxref("Temporal/Duration/months", "Temporal.Duration.prototype.months")}}
+- {{jsxref("Temporal/Duration/weeks", "Temporal.Duration.prototype.weeks")}}
+- {{jsxref("Temporal/Duration/days", "Temporal.Duration.prototype.days")}}
+- {{jsxref("Temporal/Duration/hours", "Temporal.Duration.prototype.hours")}}
+- {{jsxref("Temporal/Duration/minutes", "Temporal.Duration.prototype.minutes")}}
+- {{jsxref("Temporal/Duration/seconds", "Temporal.Duration.prototype.seconds")}}
+- {{jsxref("Temporal/Duration/milliseconds", "Temporal.Duration.prototype.milliseconds")}}
+- {{jsxref("Temporal/Duration/nanoseconds", "Temporal.Duration.prototype.nanoseconds")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/duration/milliseconds/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/duration/milliseconds/index.md
new file mode 100644
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--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/duration/milliseconds/index.md
@@ -0,0 +1,58 @@
+---
+title: Temporal.Duration.prototype.milliseconds
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Duration/milliseconds
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Duration.milliseconds
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`milliseconds`** accessor property of {{jsxref("Temporal.Duration")}} instances returns an integer representing the number of milliseconds in the duration.
+
+Unless the duration is [balanced](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#duration_balancing), you cannot assume the range of this value, but you can know its sign by checking the duration's [`sign`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration/sign) property. If it is balanced to a unit above milliseconds, the `milliseconds` absolute value will be between 0 and 999, inclusive.
+
+The set accessor of `milliseconds` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/Duration/with", "with()")}} method to create a new `Temporal.Duration` object with the desired new value.
+
+## Examples
+
+### Using milliseconds
+
+```js
+const d1 = Temporal.Duration.from({ seconds: 1, milliseconds: 500 });
+const d2 = Temporal.Duration.from({ seconds: -1, milliseconds: -500 });
+const d3 = Temporal.Duration.from({ seconds: 1 });
+const d4 = Temporal.Duration.from({ milliseconds: 1000 });
+
+console.log(d1.milliseconds); // 500
+console.log(d2.milliseconds); // -500
+console.log(d3.milliseconds); // 0
+console.log(d4.milliseconds); // 1000
+
+// Balance d4
+const d4Balanced = d4.round({ largestUnit: "second" });
+console.log(d4Balanced.milliseconds); // 0
+console.log(d4Balanced.seconds); // 1
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/Duration/years", "Temporal.Duration.prototype.years")}}
+- {{jsxref("Temporal/Duration/months", "Temporal.Duration.prototype.months")}}
+- {{jsxref("Temporal/Duration/weeks", "Temporal.Duration.prototype.weeks")}}
+- {{jsxref("Temporal/Duration/days", "Temporal.Duration.prototype.days")}}
+- {{jsxref("Temporal/Duration/hours", "Temporal.Duration.prototype.hours")}}
+- {{jsxref("Temporal/Duration/minutes", "Temporal.Duration.prototype.minutes")}}
+- {{jsxref("Temporal/Duration/seconds", "Temporal.Duration.prototype.seconds")}}
+- {{jsxref("Temporal/Duration/microseconds", "Temporal.Duration.prototype.microseconds")}}
+- {{jsxref("Temporal/Duration/nanoseconds", "Temporal.Duration.prototype.nanoseconds")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/duration/minutes/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/duration/minutes/index.md
new file mode 100644
index 000000000000000..a7e21b90a461b85
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/duration/minutes/index.md
@@ -0,0 +1,58 @@
+---
+title: Temporal.Duration.prototype.minutes
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Duration/minutes
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Duration.minutes
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`minutes`** accessor property of {{jsxref("Temporal.Duration")}} instances returns an integer representing the number of minutes in the duration.
+
+Unless the duration is [balanced](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#duration_balancing), you cannot assume the range of this value, but you can know its sign by checking the duration's [`sign`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration/sign) property. If it is balanced to a unit above minutes, the `minutes` absolute value will be between 0 and 59, inclusive.
+
+The set accessor of `minutes` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/Duration/with", "with()")}} method to create a new `Temporal.Duration` object with the desired new value.
+
+## Examples
+
+### Using minutes
+
+```js
+const d1 = Temporal.Duration.from({ hours: 1, minutes: 30 });
+const d2 = Temporal.Duration.from({ hours: -1, minutes: -30 });
+const d3 = Temporal.Duration.from({ hours: 1 });
+const d4 = Temporal.Duration.from({ minutes: 60 });
+
+console.log(d1.minutes); // 1
+console.log(d2.minutes); // -1
+console.log(d3.minutes); // 0
+console.log(d4.minutes); // 60
+
+// Balance d4
+const d4Balanced = d4.round({ largestUnit: "hour" });
+console.log(d4Balanced.minutes); // 0
+console.log(d4Balanced.hours); // 1
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/Duration/years", "Temporal.Duration.prototype.years")}}
+- {{jsxref("Temporal/Duration/months", "Temporal.Duration.prototype.months")}}
+- {{jsxref("Temporal/Duration/weeks", "Temporal.Duration.prototype.weeks")}}
+- {{jsxref("Temporal/Duration/days", "Temporal.Duration.prototype.days")}}
+- {{jsxref("Temporal/Duration/hours", "Temporal.Duration.prototype.hours")}}
+- {{jsxref("Temporal/Duration/seconds", "Temporal.Duration.prototype.seconds")}}
+- {{jsxref("Temporal/Duration/milliseconds", "Temporal.Duration.prototype.milliseconds")}}
+- {{jsxref("Temporal/Duration/microseconds", "Temporal.Duration.prototype.microseconds")}}
+- {{jsxref("Temporal/Duration/nanoseconds", "Temporal.Duration.prototype.nanoseconds")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/duration/months/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/duration/months/index.md
new file mode 100644
index 000000000000000..5b562dcb27b502c
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/duration/months/index.md
@@ -0,0 +1,61 @@
+---
+title: Temporal.Duration.prototype.months
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Duration/months
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Duration.months
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`months`** accessor property of {{jsxref("Temporal.Duration")}} instances returns an integer representing the number of months in the duration.
+
+Unless the duration is [balanced](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#duration_balancing), you cannot assume the range of this value, but you can know its sign by checking the duration's [`sign`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration/sign) property. If it is balanced to a unit above months, the `months` absolute value's range depends on the calendar (how many months are in a year).
+
+The set accessor of `months` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/Duration/with", "with()")}} method to create a new `Temporal.Duration` object with the desired new value.
+
+## Examples
+
+### Using months
+
+```js
+const d1 = Temporal.Duration.from({ years: 1, months: 1 });
+const d2 = Temporal.Duration.from({ years: -1, months: -1 });
+const d3 = Temporal.Duration.from({ years: 1 });
+const d4 = Temporal.Duration.from({ months: 12 });
+
+console.log(d1.months); // 1
+console.log(d2.months); // -1
+console.log(d3.months); // 0
+console.log(d4.months); // 12
+
+// Balance d4
+const d4Balanced = d4.round({
+  largestUnit: "year",
+  relativeTo: Temporal.PlainDate.from("2021-01-01"), // ISO 8601 calendar
+});
+console.log(d4Balanced.months); // 0
+console.log(d4Balanced.years); // 1
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/Duration/years", "Temporal.Duration.prototype.years")}}
+- {{jsxref("Temporal/Duration/weeks", "Temporal.Duration.prototype.weeks")}}
+- {{jsxref("Temporal/Duration/days", "Temporal.Duration.prototype.days")}}
+- {{jsxref("Temporal/Duration/hours", "Temporal.Duration.prototype.hours")}}
+- {{jsxref("Temporal/Duration/minutes", "Temporal.Duration.prototype.minutes")}}
+- {{jsxref("Temporal/Duration/seconds", "Temporal.Duration.prototype.seconds")}}
+- {{jsxref("Temporal/Duration/milliseconds", "Temporal.Duration.prototype.milliseconds")}}
+- {{jsxref("Temporal/Duration/microseconds", "Temporal.Duration.prototype.microseconds")}}
+- {{jsxref("Temporal/Duration/nanoseconds", "Temporal.Duration.prototype.nanoseconds")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/duration/nanoseconds/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/duration/nanoseconds/index.md
new file mode 100644
index 000000000000000..606b1c782857556
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/duration/nanoseconds/index.md
@@ -0,0 +1,58 @@
+---
+title: Temporal.Duration.prototype.nanoseconds
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Duration/nanoseconds
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Duration.nanoseconds
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`nanoseconds`** accessor property of {{jsxref("Temporal.Duration")}} instances returns an integer representing the number of nanoseconds in the duration.
+
+Unless the duration is [balanced](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#duration_balancing), you cannot assume the range of this value, but you can know its sign by checking the duration's [`sign`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration/sign) property. If it is balanced to a unit above nanoseconds, the `nanoseconds` absolute value will be between 0 and 999, inclusive.
+
+The set accessor of `nanoseconds` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/Duration/with", "with()")}} method to create a new `Temporal.Duration` object with the desired new value.
+
+## Examples
+
+### Using nanoseconds
+
+```js
+const d1 = Temporal.Duration.from({ microseconds: 1, nanoseconds: 500 });
+const d2 = Temporal.Duration.from({ microseconds: -1, nanoseconds: -500 });
+const d3 = Temporal.Duration.from({ microseconds: 1 });
+const d4 = Temporal.Duration.from({ nanoseconds: 1000 });
+
+console.log(d1.nanoseconds); // 500
+console.log(d2.nanoseconds); // -500
+console.log(d3.nanoseconds); // 0
+console.log(d4.nanoseconds); // 1000
+
+// Balance d4
+const d4Balanced = d4.round({ largestUnit: "microsecond" });
+console.log(d4Balanced.nanoseconds); // 0
+console.log(d4Balanced.microseconds); // 1
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/Duration/years", "Temporal.Duration.prototype.years")}}
+- {{jsxref("Temporal/Duration/months", "Temporal.Duration.prototype.months")}}
+- {{jsxref("Temporal/Duration/weeks", "Temporal.Duration.prototype.weeks")}}
+- {{jsxref("Temporal/Duration/days", "Temporal.Duration.prototype.days")}}
+- {{jsxref("Temporal/Duration/hours", "Temporal.Duration.prototype.hours")}}
+- {{jsxref("Temporal/Duration/minutes", "Temporal.Duration.prototype.minutes")}}
+- {{jsxref("Temporal/Duration/seconds", "Temporal.Duration.prototype.seconds")}}
+- {{jsxref("Temporal/Duration/milliseconds", "Temporal.Duration.prototype.milliseconds")}}
+- {{jsxref("Temporal/Duration/microseconds", "Temporal.Duration.prototype.microseconds")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/duration/negated/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/duration/negated/index.md
new file mode 100644
index 000000000000000..1dfb2661e34a963
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/duration/negated/index.md
@@ -0,0 +1,52 @@
+---
+title: Temporal.Duration.prototype.negated()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Duration/negated
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Duration.negated
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`negated()`** method of {{jsxref("Temporal.Duration")}} instances returns a new `Temporal.Duration` object with the negated value of this duration (all fields keep the same magnitude, but sign becomes reversed).
+
+## Syntax
+
+```js-nolint
+negated()
+```
+
+### Parameters
+
+None.
+
+### Return value
+
+A new `Temporal.Duration` object, where all fields have the same magnitude as this duration, but the sign is reversed (positive fields become negative, and vice versa).
+
+## Examples
+
+### Using negated()
+
+```js
+const d1 = Temporal.Duration.from({ hours: 1, minutes: 30 });
+const d2 = Temporal.Duration.from({ hours: -1, minutes: -30 });
+
+console.log(d1.negated().toString()); // "-PT1H30M"
+console.log(d2.negated().toString()); // "PT1H30M"
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/Duration/abs", "Temporal.Duration.prototype.abs()")}}
+- {{jsxref("Temporal/Duration/sign", "Temporal.Duration.prototype.sign")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/duration/round/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/duration/round/index.md
new file mode 100644
index 000000000000000..63037444bbf265a
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/duration/round/index.md
@@ -0,0 +1,134 @@
+---
+title: Temporal.Duration.prototype.round()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Duration/round
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Duration.round
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`round()`** method of {{jsxref("Temporal.Duration")}} instances returns a new `Temporal.Duration` object with the duration rounded to the given smallest unit and/or [balanced](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#duration_balancing) to the given largest unit.
+
+## Syntax
+
+```js-nolint
+round(smallestUnit)
+round(options)
+```
+
+### Parameters
+
+- `smallestUnit`
+  - : A string representing the [`smallestUnit`](#smallestunit_2) option. This is a convenience overload, so `round(smallestUnit)` is equivalent to `round({ smallestUnit })`, where `smallestUnit` is a string.
+- `options`
+  - : An object containing some or all of the following properties (in the order they are retrieved and validated):
+    - `largestUnit` {{optional_inline}}
+      - : Any of the temporal units: `"year"`, `"month"`, `"week"`, `"day"`, `"hour"`, `"minute"`, `"second"`, `"millisecond"`, `"microsecond"`, `"nanosecond"`, or their plural forms, or the value `"auto"` which means the largest non-zero component of this duration or `smallestUnit`, whichever is greater. Defaults to `"auto"`. The result will not contain units larger than this; for example, if the largest unit is `"minute"`, then "1 hour 30 minutes" will become "90 minutes".
+    - `relativeTo` {{optional_inline}}
+      - : A zoned or plain date(time) that provides the time and calendar information to resolve [calendar durations](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#calendar_durations) (see the link for the general interpretation of this option). Required if either `this` or `other` is a calendar duration, or `smallestUnit` is a calendar unit.
+    - `roundingIncrement` {{optional_inline}}
+      - : A number (truncated to an integer) representing the rounding increment in the given `smallestUnit`. Defaults to `1`. Must be in the inclusive range of 1 to 1e9. If the smallest unit is hours, minutes, seconds, milliseconds, microseconds, or nanoseconds, the increment must be a divisor of the maximum value of the unit; for example, if the unit is hours, the increment must be a divisor of 24 and must not be 24 itself, which means it can be 1, 2, 3, 4, 6, 8, or 12.
+    - `roundingMode` {{optional_inline}}
+      - : A string representing the rounding mode specifying to round up or down in various scenarios. See [`Intl.NumberFormat()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/NumberFormat/NumberFormat#roundingmode). Defaults to `"halfExpand"`.
+    - `smallestUnit` {{optional_inline}}
+      - : Any of the temporal units: `"year"`, `"month"`, `"week"`, `"day"`, `"hour"`, `"minute"`, `"second"`, `"millisecond"`, `"microsecond"`, `"nanosecond"`, or their plural forms. Defaults to `"nanosecond"`. For units larger than `"nanosecond"`, fractional parts of the `smallestUnit` will be rounded according to the `roundingIncrement` and `roundingMode` settings. Must be smaller or equal to `largestUnit`. At least one of `smallestUnit` and `largestUnit` must be provided.
+
+### Return value
+
+A new `Temporal.Duration` object, where the largest unit is no larger than the `largestUnit` option, and the smallest unit is no smaller than the `smallestUnit` option. The fractional parts of the `smallestUnit` are rounded according to the `roundingIncrement` and `roundingMode` settings.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown if any of the options is invalid.
+
+## Description
+
+The `round()` method performs two operations: rounding and balancing. It does the following:
+
+1. It makes sure the duration is balanced. If a component is above its preferred maximum (24 hours per day, 60 minutes per hour, etc.), the excess is carried over to the next larger unit, until we reach `largestUnit`. For example, "24 hours 90 minutes" becomes "25 hours 30 minutes" if `largestUnit` is `"auto"`, and "1 day 1 hour 30 minutes" if `largestUnit` is `"day"`.
+2. For all components larger than `largestUnit`, they are carried down into `largestUnit`; for example, "2 hours 30 minutes" becomes "150 minutes" if `largestUnit` is `"minute"`.
+3. For all components smaller than `smallestUnit`, they are carried up into `smallestUnit` as a fractional part, and then rounded according to the `roundingIncrement` and `roundingMode` settings. For example, "1 hour 30 minutes" becomes "1.5 hours" if `smallestUnit` is `"hour"`, and then rounded to "2 hours" using the default settings.
+
+[Calendar units](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#calendar_units) have uneven lengths. Their lengths are resolved relative to a starting point. For example, a duration of "2 years" in the Gregorian calendar may be 730 days or 731 days long, depending on whether it moves through a leap year or not. When rounding to a calendar unit, we first get the exact date-time represented by `relativeTo + duration`, then round it down and up according to `smallestUnit` and `roundingIncrement` to get two candidates. Then, we choose the candidate according to the `roundingMode` setting, and finally subtract `relativeTo` to get the final duration.
+
+## Examples
+
+### Rounding off small units
+
+```js
+const duration = Temporal.Duration.from({ hours: 1, minutes: 30, seconds: 15 });
+const roundedDuration = duration.round("minute");
+console.log(roundedDuration.toString()); // "PT1H30M"
+```
+
+### Avoiding larger units
+
+```js
+const duration = Temporal.Duration.from({
+  days: 3,
+  hours: 1,
+  minutes: 41,
+  seconds: 5,
+});
+const roundedDuration = duration.round({ largestUnit: "hour" });
+console.log(
+  `Time spent on this problem: ${roundedDuration.toLocaleString("en-US", { style: "digital" })}`,
+);
+// Time spent on this problem: 73:41:05
+```
+
+### Rounding to a whole number of hours
+
+```js
+const duration = Temporal.Duration.from({ days: 1, hours: 1, minutes: 30 });
+const roundedDuration = duration.round({
+  largestUnit: "hour",
+  smallestUnit: "hour",
+  roundingMode: "floor",
+});
+console.log(roundedDuration.hours); // 25
+```
+
+### Rounding by 15-minute increments
+
+```js
+const duration = Temporal.Duration.from({ hours: 1, minutes: 17 });
+const roundedDuration = duration.round({
+  smallestUnit: "minute",
+  roundingIncrement: 15,
+});
+console.log(
+  `The queue will take approximately ${roundedDuration.toLocaleString("en-US")}`,
+);
+// The queue will take approximately 1 hr, 15 min
+```
+
+### Resolving calendar durations
+
+If either the initial duration or largest/smallest unit contains a calendar unit, you must provide a `relativeTo` option to resolve the calendar durations.
+
+```js
+const duration = Temporal.Duration.from({ months: 1, days: 1, hours: 1 });
+const roundedDuration = duration.round({
+  largestUnit: "day",
+  smallestUnit: "day",
+  relativeTo: Temporal.PlainDateTime.from("2022-01-01"),
+});
+console.log(roundedDuration); // "P32D"
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/Duration/total", "Temporal.Duration.prototype.total()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/duration/seconds/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/duration/seconds/index.md
new file mode 100644
index 000000000000000..642fd07c9ddb7fc
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/duration/seconds/index.md
@@ -0,0 +1,58 @@
+---
+title: Temporal.Duration.prototype.seconds
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Duration/seconds
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Duration.seconds
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`seconds`** accessor property of {{jsxref("Temporal.Duration")}} instances returns an integer representing the number of seconds in the duration.
+
+Unless the duration is [balanced](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#duration_balancing), you cannot assume the range of this value, but you can know its sign by checking the duration's [`sign`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration/sign) property. If it is balanced to a unit above seconds, the `seconds` absolute value will be between 0 and 59, inclusive.
+
+The set accessor of `seconds` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/Duration/with", "with()")}} method to create a new `Temporal.Duration` object with the desired new value.
+
+## Examples
+
+### Using seconds
+
+```js
+const d1 = Temporal.Duration.from({ minutes: 1, seconds: 30 });
+const d2 = Temporal.Duration.from({ minutes: -1, seconds: -30 });
+const d3 = Temporal.Duration.from({ minutes: 1 });
+const d4 = Temporal.Duration.from({ seconds: 60 });
+
+console.log(d1.seconds); // 30
+console.log(d2.seconds); // -30
+console.log(d3.seconds); // 0
+console.log(d4.seconds); // 60
+
+// Balance d4
+const d4Balanced = d4.round({ largestUnit: "minute" });
+console.log(d4Balanced.seconds); // 0
+console.log(d4Balanced.minutes); // 1
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/Duration/years", "Temporal.Duration.prototype.years")}}
+- {{jsxref("Temporal/Duration/months", "Temporal.Duration.prototype.months")}}
+- {{jsxref("Temporal/Duration/weeks", "Temporal.Duration.prototype.weeks")}}
+- {{jsxref("Temporal/Duration/days", "Temporal.Duration.prototype.days")}}
+- {{jsxref("Temporal/Duration/hours", "Temporal.Duration.prototype.hours")}}
+- {{jsxref("Temporal/Duration/minutes", "Temporal.Duration.prototype.minutes")}}
+- {{jsxref("Temporal/Duration/milliseconds", "Temporal.Duration.prototype.milliseconds")}}
+- {{jsxref("Temporal/Duration/microseconds", "Temporal.Duration.prototype.microseconds")}}
+- {{jsxref("Temporal/Duration/nanoseconds", "Temporal.Duration.prototype.nanoseconds")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/duration/sign/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/duration/sign/index.md
new file mode 100644
index 000000000000000..80eabea7910fa01
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/duration/sign/index.md
@@ -0,0 +1,49 @@
+---
+title: Temporal.Duration.prototype.sign
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Duration/sign
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Duration.sign
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`sign`** accessor property of {{jsxref("Temporal.Duration")}} instances returns `1` if this duration is positive, `-1` if negative, and `0` if zero. Because [a duration never has mixed signs](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#duration_sign), the sign of a duration is determined by the sign of any of its non-zero fields.
+
+## Examples
+
+### Using sign
+
+```js
+const d1 = Temporal.Duration.from({ hours: 1, minutes: 30 });
+const d2 = Temporal.Duration.from({ hours: -1, minutes: -30 });
+const d3 = Temporal.Duration.from({ hours: 0 });
+
+console.log(d1.sign); // 1
+console.log(d2.sign); // -1
+console.log(d3.sign); // 0
+
+console.log(d1.abs().sign); // 1
+console.log(d2.abs().sign); // 1
+console.log(d3.abs().sign); // 0
+
+console.log(d1.negated().sign); // -1
+console.log(d2.negated().sign); // 1
+console.log(d3.negated().sign); // 0
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/Duration/abs", "Temporal.Duration.prototype.abs()")}}
+- {{jsxref("Temporal/Duration/negated", "Temporal.Duration.prototype.negated()")}}
+- {{jsxref("Temporal/Duration/blank", "Temporal.Duration.prototype.blank")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/duration/subtract/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/duration/subtract/index.md
new file mode 100644
index 000000000000000..9b72d63df261f0d
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/duration/subtract/index.md
@@ -0,0 +1,62 @@
+---
+title: Temporal.Duration.prototype.subtract()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Duration/subtract
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Duration.subtract
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`subtract()`** method of {{jsxref("Temporal.Duration")}} instances returns a new `Temporal.Duration` object with the difference between this duration and a given duration. It is equivalent to [adding](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration/add) the [negated](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration/negated) value of the other duration.
+
+## Syntax
+
+```js-nolint
+subtract(other)
+```
+
+### Parameters
+
+- `other`
+  - : A string, an object, or a {{jsxref("Temporal.Duration")}} instance representing a duration to add to this duration. It is converted to a `Temporal.Duration` object using the same algorithm as {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}.
+
+### Return value
+
+A new `Temporal.Duration` object representing the difference of this duration and `other`.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown in one of the following cases:
+    - Either `this` or `other` is a [calendar duration](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#calendar_durations) (it has a non-zero `years`, `months`, or `weeks`), because calendar durations are ambiguous without a calendar and time reference.
+    - The difference of `this` and `other` overflows the maximum or underflows the minimum representable duration, which is ±2<sup>53</sup> seconds.
+
+## Examples
+
+### Using subtract()
+
+```js
+const d1 = Temporal.Duration.from({ hours: 1, minutes: 30 });
+const d2 = Temporal.Duration.from({ hours: -1, minutes: -20 });
+
+const d3 = d1.subtract(d2);
+console.log(d3.toString()); // "PT2H50M"
+```
+
+For more examples and caveats, see the [`add()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration/add) method.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/Duration/add", "Temporal.Duration.prototype.add()")}}
+- {{jsxref("Temporal/Duration/negated", "Temporal.Duration.prototype.negated()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/duration/tojson/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/duration/tojson/index.md
new file mode 100644
index 000000000000000..630487d08ae1485
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/duration/tojson/index.md
@@ -0,0 +1,70 @@
+---
+title: Temporal.Duration.prototype.toJSON()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Duration/toJSON
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Duration.toJSON
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toJSON()`** method of {{jsxref("Temporal.Duration")}} instances returns a string representing this duration in the same [ISO 8601 format](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#iso_8601_duration_format) as calling {{jsxref("Temporal/Duration/toString", "toString()")}}. It is intended to be implicitly called by {{jsxref("JSON.stringify()")}}.
+
+## Syntax
+
+```js-nolint
+toJSON()
+```
+
+### Parameters
+
+None.
+
+### Return value
+
+A string representing the given duration in the [ISO 8601 format](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#iso_8601_duration_format), with as much subsecond precision as necessary to represent the duration accurately.
+
+## Description
+
+The `toJSON()` method is automatically called by {{jsxref("JSON.stringify()")}} when a `Temporal.Duration` object is stringified. This method is generally intended to, by default, usefully serialize `Temporal.Duration` objects during [JSON](/en-US/docs/Glossary/JSON) serialization, which can then be deserialized using the {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}} function as the reviver of {{jsxref("JSON.parse()")}}.
+
+## Examples
+
+### Using toJSON()
+
+```js
+const duration = Temporal.Duration.from({ hours: 1, minutes: 30, seconds: 15 });
+const durationStr = duration.toJSON(); // 'PT1H30M15S'
+const d2 = Temporal.Duration.from(durationStr);
+```
+
+### JSON serialization and parsing
+
+This example shows how `Temporal.Duration` can be serialized as JSON without extra effort, and how to parse it back.
+
+```js
+const duration = Temporal.Duration.from({ hours: 1, minutes: 30, seconds: 15 });
+const jsonStr = JSON.stringify({ data: duration }); // '{"data":"PT1H30M15S"}'
+const obj = JSON.parse(jsonStr, (key, value) => {
+  if (key === "data") {
+    return Temporal.Duration.from(value);
+  }
+  return value;
+});
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}
+- {{jsxref("Temporal/Duration/toString", "Temporal.Duration.prototype.toString()")}}
+- {{jsxref("Temporal/Duration/toLocaleString", "Temporal.Duration.prototype.toLocaleString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/duration/tolocalestring/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/duration/tolocalestring/index.md
new file mode 100644
index 000000000000000..48f2d08b0b63efa
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/duration/tolocalestring/index.md
@@ -0,0 +1,71 @@
+---
+title: Temporal.Duration.prototype.toLocaleString()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Duration/toLocaleString
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Duration.toLocaleString
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toLocaleString()`** method of {{jsxref("Temporal.Duration")}} instances returns a string with a language-sensitive representation of this duration. In implementations with [`Intl.DurationFormat` API](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DurationFormat) support, this method delegates to `Intl.DurationFormat`.
+
+Every time `toLocaleString` is called, it has to perform a search in a big database of localization strings, which is potentially inefficient. When the method is called many times with the same arguments, it is better to create a {{jsxref("Intl.DurationFormat")}} object and use its {{jsxref("Intl/DurationFormat/format", "format()")}} method, because a `DurationFormat` object remembers the arguments passed to it and may decide to cache a slice of the database, so future `format` calls can search for localization strings within a more constrained context.
+
+## Syntax
+
+```js-nolint
+toLocaleString()
+toLocaleString(locales)
+toLocaleString(locales, options)
+```
+
+### Parameters
+
+The `locales` and `options` parameters customize the behavior of the function and let applications specify the language whose formatting conventions should be used.
+
+In implementations that support the [`Intl.DurationFormat` API](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DurationFormat), these parameters correspond exactly to the [`Intl.DurationFormat()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DurationFormat/DurationFormat) constructor's parameters. Implementations without `Intl.DurationFormat` support return the exact same string as {{jsxref("Temporal/Duration/toString", "toString()")}}, ignoring both parameters.
+
+- `locales` {{optional_inline}}
+  - : A string with a BCP 47 language tag, or an array of such strings. Corresponds to the [`locales`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DurationFormat/DurationFormat#locales) parameter of the `Intl.DurationFormat()` constructor.
+- `options` {{optional_inline}}
+  - : An object adjusting the output format. Corresponds to the [`options`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DurationFormat/DurationFormat#options) parameter of the `Intl.DurationFormat()` constructor.
+
+See the [`Intl.DurationFormat()` constructor](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DurationFormat/DurationFormat) for details on these parameters and how to use them.
+
+### Return value
+
+A string representing the given duration according to language-specific conventions.
+
+In implementations with `Intl.DurationFormat`, this is equivalent to `new Intl.DurationFormat(locales, options).format(duration)`.
+
+> [!NOTE]
+> Most of the time, the formatting returned by `toLocaleString()` is consistent. However, the output may vary between implementations, even within the same locale — output variations are by design and allowed by the specification. It may also not be what you expect. For example, the string may use non-breaking spaces or be surrounded by bidirectional control characters. You should not compare the results of `toLocaleString()` to hardcoded constants.
+
+## Examples
+
+### Using toLocaleString()
+
+Basic use of this method without specifying a `locale` returns a formatted string in the default locale and with default options.
+
+```js
+const duration = Temporal.Duration.from({ hours: 1, minutes: 30, seconds: 15 });
+
+console.log(duration.toLocaleString()); // 1 hr, 30 min, 15 sec
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Intl.DurationFormat")}}
+- {{jsxref("Temporal/Duration/toJSON", "Temporal.Duration.prototype.toJSON()")}}
+- {{jsxref("Temporal/Duration/toString", "Temporal.Duration.prototype.toString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/duration/tostring/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/duration/tostring/index.md
new file mode 100644
index 000000000000000..cf3cfd360271d42
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/duration/tostring/index.md
@@ -0,0 +1,81 @@
+---
+title: Temporal.Duration.prototype.toString()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Duration/toString
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Duration.toString
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toString()`** method of {{jsxref("Temporal.Duration")}} instances returns a string representing this duration in the [ISO 8601 format](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#iso_8601_duration_format).
+
+## Syntax
+
+```js-nolint
+toString()
+toString(options)
+```
+
+### Parameters
+
+- `options` {{optional_inline}}
+  - : An object containing some or all of the following properties (in the order they are retrieved and validated):
+    - `fractionalSecondDigits` {{optional_inline}}
+      - : Either an integer from 0 to 9, or the string `"auto"`. The default is `"auto"`. If `"auto"`, then trailing zeros are removed from the fractional seconds. Otherwise, the fractional part of the second component contains this many digits, padded with zeros or rounded as necessary.
+    - `roundingMode` {{optional_inline}}
+      - : A string specifying how to round off fractional second digits beyond `fractionalSecondDigits`. See [`Intl.NumberFormat()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/NumberFormat/NumberFormat#roundingmode). Defaults to `"trunc"`.
+    - `smallestUnit` {{optional_inline}}
+      - : A string specifying the smallest unit to include in the output. Possible values are `"second"`, `"millisecond"`, `"microsecond"`, and `"nanosecond"`, or their plural forms, which are equivalent to `fractionalSecondDigits` values of `0`, `3`, `6`, `9`, respectively. If specified, then `fractionalSecondDigits` is ignored.
+
+### Return value
+
+A string representing the given duration in the [ISO 8601 format](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#iso_8601_duration_format), with subsecond components formatted according to the options. The zero duration is represented as `"PT0S"`.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown if any of the options is invalid.
+
+## Examples
+
+### Using toString()
+
+```js
+const duration = Temporal.Duration.from({ hours: 1, minutes: 30, seconds: 15 });
+console.log(duration.toString()); // 'PT1H30M15S'
+
+// Stringification implicitly calls toString()
+console.log(`${duration}`); // 'PT1H30M15S'
+```
+
+### Using options
+
+```js
+const worldRecord = Temporal.Duration.from({ seconds: 9, milliseconds: 580 });
+console.log(worldRecord.toString()); // 'PT9.58S'
+console.log(worldRecord.toString({ fractionalSecondDigits: 1 })); // 'PT9.5S'
+console.log(worldRecord.toString({ fractionalSecondDigits: 0 })); // 'PT9S'
+console.log(worldRecord.toString({ smallestUnit: "millisecond" })); // 'PT9.580S'
+console.log(
+  worldRecord.toString({
+    fractionalSecondDigits: 1,
+    roundingMode: "halfExpand",
+  }),
+); // 'PT9.6S'
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/Duration/toJSON", "Temporal.Duration.prototype.toJSON()")}}
+- {{jsxref("Temporal/Duration/toLocaleString", "Temporal.Duration.prototype.toLocaleString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/duration/total/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/duration/total/index.md
new file mode 100644
index 000000000000000..dba7b7d09bae6a2
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/duration/total/index.md
@@ -0,0 +1,81 @@
+---
+title: Temporal.Duration.prototype.total()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Duration/total
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Duration.total
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`total()`** method of {{jsxref("Temporal.Duration")}} instances returns a number representing the total duration in the given unit.
+
+## Syntax
+
+```js-nolint
+total(unit)
+total(options)
+```
+
+### Parameters
+
+- `unit`
+  - : A string representing the [`unit`](#unit_2) option. This is a convenience overload, so `total(unit)` is equivalent to `total({ unit })`, where `unit` is a string.
+- `options`
+  - : An object containing some or all of the following properties (in the order they are retrieved and validated):
+    - `relativeTo` {{optional_inline}}
+      - : A zoned or plain date(time) that provides the time and calendar information to resolve [calendar durations](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#calendar_durations) (see the link for the general interpretation of this option). Required if either `this` or `other` is a calendar duration, or `unit` is a calendar unit.
+    - `unit`
+      - : Any of the temporal units: `"year"`, `"month"`, `"week"`, `"day"`, `"hour"`, `"minute"`, `"second"`, `"millisecond"`, `"microsecond"`, `"nanosecond"`, or their plural forms.
+
+### Return value
+
+A floating-point number representing the total duration in the given unit. May be inexact due to floating point precision limits.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown in one of the following cases:
+    - `unit` is not provided or is not a valid unit.
+    - Either `this` or `other` is a calendar duration, or `unit` is a calendar unit, and `relativeTo` is not provided.
+
+## Description
+
+If a `relativeTo` is provided, the result is calculated by adding the duration to the starting point, finding the difference between the result and the starting point (in nanoseconds), and then converting the difference to the requested unit by dividing by the appropriate number of nanoseconds per unit. Providing a zoned date-time allows daylight saving time and other time zone changes to be taken into account too; otherwise, 24-hour days are assumed.
+
+If `relativeTo` is not provided, the result is calculated by converting the duration to nanoseconds and dividing by the appropriate number of nanoseconds per unit.
+
+## Examples
+
+### Using total()
+
+```js
+const d = Temporal.Duration.from({ hours: 1, minutes: 30 });
+
+console.log(d.total("minutes")); // 90
+console.log(d.total("hours")); // 1.5
+```
+
+### Total of a calendar duration
+
+```js
+const d = Temporal.Duration.from({ months: 1 });
+
+console.log(
+  d.total({ unit: "days", relativeTo: Temporal.PlainDate.from("2021-01-01") }),
+); // 31
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/Duration/round", "Temporal.Duration.prototype.round()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/duration/valueof/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/duration/valueof/index.md
new file mode 100644
index 000000000000000..cecf4cd0af5f5d1
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/duration/valueof/index.md
@@ -0,0 +1,68 @@
+---
+title: Temporal.Duration.prototype.valueOf()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Duration/valueOf
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Duration.valueOf
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`valueOf()`** method of {{jsxref("Temporal.Duration")}} instances throws a {{jsxref("TypeError")}}, which prevents `Temporal.Duration` instances from being [implicitly converted to primitives](/en-US/docs/Web/JavaScript/Data_structures#primitive_coercion) when used in arithmetic or comparison operations.
+
+## Syntax
+
+```js-nolint
+valueOf()
+```
+
+### Parameters
+
+None.
+
+### Return value
+
+None.
+
+### Exceptions
+
+- {{jsxref("TypeError")}}
+  - : Always thrown.
+
+## Description
+
+Because both [primitive conversion](/en-US/docs/Web/JavaScript/Data_structures#primitive_coercion) and [number conversion](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number#number_coercion) call `valueOf()` before `toString()`, if `valueOf()` is absent, then an expression like `duration1 > duration2` would implicitly compare them as strings, which may have unexpected results such as `"PT3S" > "PT1M"`. By throwing a `TypeError`, `Temporal.Duration` instances prevent such implicit conversions. You need to explicitly convert them to numbers using {{jsxref("Temporal/Duration/total", "Temporal.Duration.prototype.total()")}}, or use the {{jsxref("Temporal/Duration/compare", "Temporal.Duration.compare()")}} static method to compare them.
+
+## Examples
+
+### Arithmetic and comparison operations on Temporal.Duration
+
+All arithmetic and comparison operations on `Temporal.Duration` instances should use the dedicated methods or convert them to primitives explicitly.
+
+```js
+const duration1 = Temporal.Duration.from({ seconds: 3 });
+const duration2 = Temporal.Duration.from({ minutes: 1 });
+duration1 > duration2; // TypeError: can't convert Duration to primitive type
+duration1.total("seconds") > duration2.total("seconds"); // false
+Temporal.Duration.compare(duration1, duration2); // -1
+
+duration1 + duration2; // TypeError: can't convert Duration to primitive type
+duration1.total("seconds") + duration2.total("seconds"); // 63
+duration1.add(duration2).toString(); // "PT1M3S"
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/Duration/toString", "Temporal.Duration.prototype.toString()")}}
+- {{jsxref("Temporal/Duration/toJSON", "Temporal.Duration.prototype.toJSON()")}}
+- {{jsxref("Temporal/Duration/toLocaleString", "Temporal.Duration.prototype.toLocaleString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/duration/weeks/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/duration/weeks/index.md
new file mode 100644
index 000000000000000..dd12bc676759bf4
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/duration/weeks/index.md
@@ -0,0 +1,61 @@
+---
+title: Temporal.Duration.prototype.weeks
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Duration/weeks
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Duration.weeks
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`weeks`** accessor property of {{jsxref("Temporal.Duration")}} instances returns an integer representing the number of weeks in the duration.
+
+Unless the duration is [balanced](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#duration_balancing), you cannot assume the range of this value, but you can know its sign by checking the duration's [`sign`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration/sign) property. If it is balanced to a unit above weeks, the `weeks` absolute value's range depends on the calendar (how many weeks are in a month or year).
+
+The set accessor of `weeks` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/Duration/with", "with()")}} method to create a new `Temporal.Duration` object with the desired new value.
+
+## Examples
+
+### Using weeks
+
+```js
+const d1 = Temporal.Duration.from({ weeks: 1, days: 1 });
+const d2 = Temporal.Duration.from({ weeks: -1, days: -1 });
+const d3 = Temporal.Duration.from({ weeks: 1 });
+const d4 = Temporal.Duration.from({ days: 7 });
+
+console.log(d1.weeks); // 1
+console.log(d2.weeks); // -1
+console.log(d3.weeks); // 1
+console.log(d4.weeks); // 0
+
+// Balance d4
+const d4Balanced = d4.round({
+  largestUnit: "week",
+  relativeTo: Temporal.PlainDate.from("2021-01-01"), // ISO 8601 calendar
+});
+console.log(d4Balanced.weeks); // 1
+console.log(d4Balanced.days); // 0
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/Duration/years", "Temporal.Duration.prototype.years")}}
+- {{jsxref("Temporal/Duration/months", "Temporal.Duration.prototype.months")}}
+- {{jsxref("Temporal/Duration/days", "Temporal.Duration.prototype.days")}}
+- {{jsxref("Temporal/Duration/hours", "Temporal.Duration.prototype.hours")}}
+- {{jsxref("Temporal/Duration/minutes", "Temporal.Duration.prototype.minutes")}}
+- {{jsxref("Temporal/Duration/seconds", "Temporal.Duration.prototype.seconds")}}
+- {{jsxref("Temporal/Duration/milliseconds", "Temporal.Duration.prototype.milliseconds")}}
+- {{jsxref("Temporal/Duration/microseconds", "Temporal.Duration.prototype.microseconds")}}
+- {{jsxref("Temporal/Duration/nanoseconds", "Temporal.Duration.prototype.nanoseconds")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/duration/with/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/duration/with/index.md
new file mode 100644
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--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/duration/with/index.md
@@ -0,0 +1,77 @@
+---
+title: Temporal.Duration.prototype.with()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Duration/with
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Duration.with
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`with()`** method of {{jsxref("Temporal.Duration")}} instances returns a new `Temporal.Duration` object representing this duration with some fields replaced by new values. Because all `Temporal` objects are designed to be immutable, this method essentially functions as the setter for the duration's fields.
+
+## Syntax
+
+```js-nolint
+with(info)
+```
+
+### Parameters
+
+- `info`
+  - : An object containing at least one of the properties recognized by {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}: `years`, `months`, `weeks`, `days`, `hours`, `minutes`, `seconds`, `milliseconds`, `microseconds`, `nanoseconds`. Unspecified properties use the values from the original duration.
+
+### Return value
+
+A new `Temporal.Duration` object, where the fields specified in `info` that are not `undefined` are replaced by the corresponding values, and the rest of the fields are copied from the original duration.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown in one of the following cases:
+    - Any of the recognized properties in the `info` object is not an integer (including non-finite values).
+    - A [calendar unit](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#calendar_durations) (years, months, weeks) has an absolute value ≥ 2<sup>32</sup>.
+    - The non-calendar part of the duration (days and below), when expressed in seconds, has an absolute value ≥ 2<sup>53</sup>.
+- {{jsxref("TypeError")}}
+  - : Thrown in one of the following cases:
+    - The `info` object is not an object.
+    - All of the recognized properties in the `info` object are `undefined`.
+
+## Examples
+
+### Using with()
+
+You can use `with()` to achieve fine-grained control over the fields of a `Temporal.Duration` object. For example, you can manually [balance](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#duration_balancing) a duration only on one unit, which `round()` does not offer:
+
+```js
+function balanceMinutes(duration) {
+  const { hours, minutes } = duration;
+  const totalMinutes = hours * 60 + minutes;
+  const balancedMinutes = totalMinutes % 60;
+  const balancedHours = (totalMinutes - balancedMinutes) / 60;
+  return duration.with({ hours: balancedHours, minutes: balancedMinutes });
+}
+
+const d1 = Temporal.Duration.from({ hours: 100, minutes: 100, seconds: 100 });
+const d2 = balanceMinutes(d1);
+console.log(d2.hours); // 101
+console.log(d2.minutes); // 40
+console.log(d2.seconds); // 100; remains unbalanced
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}
+- {{jsxref("Temporal/Duration/add", "Temporal.Duration.prototype.add()")}}
+- {{jsxref("Temporal/Duration/subtract", "Temporal.Duration.prototype.subtract()")}}
+- {{jsxref("Temporal/Duration/round", "Temporal.Duration.prototype.round()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/duration/years/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/duration/years/index.md
new file mode 100644
index 000000000000000..78977f466c230f4
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/duration/years/index.md
@@ -0,0 +1,61 @@
+---
+title: Temporal.Duration.prototype.years
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Duration/years
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Duration.years
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`years`** accessor property of {{jsxref("Temporal.Duration")}} instances returns an integer representing the number of years in the duration.
+
+You can know the sign of `years` by checking the duration's [`sign`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration/sign) property.
+
+The set accessor of `years` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/Duration/with", "with()")}} method to create a new `Temporal.Duration` object with the desired new value.
+
+## Examples
+
+### Using years
+
+```js
+const d1 = Temporal.Duration.from({ years: 1, months: 1 });
+const d2 = Temporal.Duration.from({ years: -1, months: -1 });
+const d3 = Temporal.Duration.from({ years: 1 });
+const d4 = Temporal.Duration.from({ months: 12 });
+
+console.log(d1.years); // 1
+console.log(d2.years); // -1
+console.log(d3.years); // 1
+console.log(d4.years); // 0
+
+// Balance d4
+const d4Balanced = d4.round({
+  largestUnit: "year",
+  relativeTo: Temporal.PlainDate.from("2021-01-01"), // ISO 8601 calendar
+});
+console.log(d4Balanced.years); // 1
+console.log(d4Balanced.months); // 0
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/Duration/months", "Temporal.Duration.prototype.months")}}
+- {{jsxref("Temporal/Duration/weeks", "Temporal.Duration.prototype.weeks")}}
+- {{jsxref("Temporal/Duration/days", "Temporal.Duration.prototype.days")}}
+- {{jsxref("Temporal/Duration/hours", "Temporal.Duration.prototype.hours")}}
+- {{jsxref("Temporal/Duration/minutes", "Temporal.Duration.prototype.minutes")}}
+- {{jsxref("Temporal/Duration/seconds", "Temporal.Duration.prototype.seconds")}}
+- {{jsxref("Temporal/Duration/milliseconds", "Temporal.Duration.prototype.milliseconds")}}
+- {{jsxref("Temporal/Duration/microseconds", "Temporal.Duration.prototype.microseconds")}}
+- {{jsxref("Temporal/Duration/nanoseconds", "Temporal.Duration.prototype.nanoseconds")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/index.md
new file mode 100644
index 000000000000000..f05e143c3ff5b23
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/index.md
@@ -0,0 +1,363 @@
+---
+title: Temporal
+slug: Web/JavaScript/Reference/Global_Objects/Temporal
+page-type: javascript-namespace
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal`** object enables date and time management in various scenarios, including built-in time zone and calendar representation, wall-clock time conversions, arithmetics, formatting, and more. It is designed as a full replacement for the {{jsxref("Date")}} object.
+
+## Description
+
+Unlike most global objects, `Temporal` is not a constructor. You cannot use it with the [`new` operator](/en-US/docs/Web/JavaScript/Reference/Operators/new) or invoke the `Temporal` object as a function. All properties and methods of `Temporal` are static (just like the {{jsxref("Math")}} object).
+
+`Temporal` has an intricate and powerful API. It exposes over 200 utility methods via several classes, so it could appear very complex. We will provide a high-level overview of how these APIs are related to each other.
+
+### Background and concepts
+
+JavaScript has had the {{jsxref("Date")}} object for handling date and time since its first days. However, the `Date` API is based on the poorly designed `java.util.Date` class from Java, which was replaced in the early 2010s; but, because of JavaScript's goal of backward compatibility, `Date` sticks around in the language.
+
+The important lesson to preface the whole introduction is that **date handling is complex**. Most of the problems of `Date` are fixable by adding more methods, but a fundamental design flaw remains: it exposes so many methods on the same object that developers are often confused about what to use, leading to unexpected pitfalls. A well-designed API not only needs to do more, but also should do _less_ with each level of abstraction, because preventing misuse is as important as enabling use cases.
+
+`Date` objects wear two hats simultaneously:
+
+- As a [timestamp](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date#the_epoch_timestamps_and_invalid_date): the number of milliseconds or nanoseconds elapsed since a fixed point in time (known as the _epoch_).
+- As a combination of [components](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date#date_components_and_time_zones): year, month, day, hour, minute, second, millisecond, and nanosecond. The year, month, and day identifiers only make sense with reference to a _calendar system_. The whole combination maps to a unique instant in history when associated with a time zone. `Date` objects provide methods for reading and modifying these components.
+
+[Time zones](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#time_zones_and_offsets) underlie a significant number of date-related bugs. When interacting with a `Date` via the "combination of components" model, the time can only be in two time zones: UTC and local (device), and there's no way to specify an arbitrary time zone. Also lacking is the concept of "no time zone": this is known as a _calendar date_ (for dates) or _wall-clock time_ (for times), which is a time you "read off a calendar or clock". For example, if you are setting a daily wake up alarm, you will want to set it to "8:00AM" regardless of whether it is daylight saving time or not, whether you have traveled to a different time zone, etc.
+
+A second feature lacking from `Date` is a [calendar system](#calendars). Most people may be familiar with the Gregorian calendar, where there are two eras, BC and AD; there are 12 months; each month has a different number of days; there's a leap year every 4 years; and so on. However, some of these concepts may not apply when you are working with another calendar system, such as the Hebrew calendar, the Chinese calendar, the Japanese calendar, etc. With `Date`, you can only work with the Gregorian calendar model.
+
+There are many other undesirable legacies about `Date`, such as all setters being mutating (which often causes unwanted side effects), the [date time string format](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date#date_time_string_format) being impossible to parse in a consistent way, etc. In the end, the best solution is to build a new API from scratch, which is what `Temporal` is.
+
+### API overview
+
+`Temporal` is a namespace, like {{jsxref("Intl")}}. It contains several classes and namespaces, each of which is designed to handle a specific aspect of date and time management. The classes can be grouped as such:
+
+- Representing a time duration (a difference between two time points): {{jsxref("Temporal.Duration")}}
+- Representing a time point:
+  - Representing a unique instant in history:
+    - As a timestamp: {{jsxref("Temporal.Instant")}}
+    - As a date-time component combination paired with a time zone: {{jsxref("Temporal.ZonedDateTime")}}
+  - Representing a time-zone-unaware date/time (which are all prefixed with "Plain"):
+    - Date (year, month, day) + time (hour, minute, second, millisecond, nanosecond): {{jsxref("Temporal.PlainDateTime")}} (Note: `ZonedDateTime` is equivalent to `PlainDateTime` plus a time zone)
+      - Date (year, month, day): {{jsxref("Temporal.PlainDate")}}
+        - Year, month: {{jsxref("Temporal.PlainYearMonth")}}
+        - Month, day: {{jsxref("Temporal.PlainMonthDay")}}
+      - Time (hour, minute, second, millisecond, nanosecond): {{jsxref("Temporal.PlainTime")}}
+
+Furthermore, there's also another utility namespace, {{jsxref("Temporal.Now")}}, which provides methods for getting the current time in various formats.
+
+### Shared class interface
+
+There are many classes in the `Temporal` namespace, but they share many similar methods. The following table lists all methods of each class (except [conversion methods](#conversion_between_classes)):
+
+<table>
+<thead>
+<tr>
+<td></td>
+<th><code>Instant</code></th>
+<th><code>ZonedDateTime</code></th>
+<th><code>PlainDateTime</code></th>
+<th><code>PlainDate</code></th>
+<th><code>PlainTime</code></th>
+<th><code>PlainYearMonth</code></th>
+<th><code>PlainMonthDay</code></th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<th>Construction</th>
+<td>{{jsxref("Temporal/Instant/Instant", "Instant()")}}<br>{{jsxref("Temporal/Instant/from", "Instant.from()")}}<br>{{jsxref("Temporal/Instant/fromEpochMilliseconds", "Instant.fromEpochMilliseconds()")}}<br>{{jsxref("Temporal/Instant/fromEpochNanoseconds", "Instant.fromEpochNanoseconds()")}}</td>
+<td>{{jsxref("Temporal/ZonedDateTime/ZonedDateTime", "ZonedDateTime()")}}<br>{{jsxref("Temporal/ZonedDateTime/from", "ZonedDateTime.from()")}}</td>
+<td>{{jsxref("Temporal/PlainDateTime/PlainDateTime", "PlainDateTime()")}}<br>{{jsxref("Temporal/PlainDateTime/from", "PlainDateTime.from()")}}</td>
+<td>{{jsxref("Temporal/PlainDate/PlainDate", "PlainDate()")}}<br>{{jsxref("Temporal/PlainDate/from", "PlainDate.from()")}}</td>
+<td>{{jsxref("Temporal/PlainTime/PlainTime", "PlainTime()")}}<br>{{jsxref("Temporal/PlainTime/from", "PlainTime.from()")}}</td>
+<td>{{jsxref("Temporal/PlainYearMonth/PlainYearMonth", "PlainYearMonth()")}}<br>{{jsxref("Temporal/PlainYearMonth/from", "PlainYearMonth.from()")}}</td>
+<td>{{jsxref("Temporal/PlainMonthDay/PlainMonthDay", "PlainMonthDay()")}}<br>{{jsxref("Temporal/PlainMonthDay/from", "PlainMonthDay.from()")}}</td>
+</tr>
+<tr>
+<th>Updater</th>
+<td>N/A</td>
+<td>{{jsxref("Temporal/ZonedDateTime/with", "with()")}}<br>{{jsxref("Temporal/ZonedDateTime/withCalendar", "withCalendar()")}}<br>{{jsxref("Temporal/ZonedDateTime/withTimeZone", "withTimeZone()")}}<br>{{jsxref("Temporal/ZonedDateTime/withPlainTime", "withPlainTime()")}}</td>
+<td>{{jsxref("Temporal/PlainDateTime/with", "with()")}}<br>{{jsxref("Temporal/PlainDateTime/withCalendar", "withCalendar()")}}<br>{{jsxref("Temporal/PlainDateTime/withPlainTime", "withPlainTime()")}}</td>
+<td>{{jsxref("Temporal/PlainDate/with", "with()")}}<br>{{jsxref("Temporal/PlainDate/withCalendar", "withCalendar()")}}</td>
+<td>{{jsxref("Temporal/PlainTime/with", "with()")}}</td>
+<td>{{jsxref("Temporal/PlainYearMonth/with", "with()")}}</td>
+<td>{{jsxref("Temporal/PlainMonthDay/with", "with()")}}</td>
+</tr>
+<tr>
+<th>Arithmetic</th>
+<td>{{jsxref("Temporal/Instant/add", "add()")}}<br>{{jsxref("Temporal/Instant/subtract", "subtract()")}}<br>{{jsxref("Temporal/Instant/since", "since()")}}<br>{{jsxref("Temporal/Instant/until", "until()")}}</td>
+<td>{{jsxref("Temporal/ZonedDateTime/add", "add()")}}<br>{{jsxref("Temporal/ZonedDateTime/subtract", "subtract()")}}<br>{{jsxref("Temporal/ZonedDateTime/since", "since()")}}<br>{{jsxref("Temporal/ZonedDateTime/until", "until()")}}</td>
+<td>{{jsxref("Temporal/PlainDateTime/add", "add()")}}<br>{{jsxref("Temporal/PlainDateTime/subtract", "subtract()")}}<br>{{jsxref("Temporal/PlainDateTime/since", "since()")}}<br>{{jsxref("Temporal/PlainDateTime/until", "until()")}}</td>
+<td>{{jsxref("Temporal/PlainDate/add", "add()")}}<br>{{jsxref("Temporal/PlainDate/subtract", "subtract()")}}<br>{{jsxref("Temporal/PlainDate/since", "since()")}}<br>{{jsxref("Temporal/PlainDate/until", "until()")}}</td>
+<td>{{jsxref("Temporal/PlainTime/add", "add()")}}<br>{{jsxref("Temporal/PlainTime/subtract", "subtract()")}}<br>{{jsxref("Temporal/PlainTime/since", "since()")}}<br>{{jsxref("Temporal/PlainTime/until", "until()")}}</td>
+<td>{{jsxref("Temporal/PlainYearMonth/add", "add()")}}<br>{{jsxref("Temporal/PlainYearMonth/subtract", "subtract()")}}<br>{{jsxref("Temporal/PlainYearMonth/since", "since()")}}<br>{{jsxref("Temporal/PlainYearMonth/until", "until()")}}</td>
+<td>N/A</td>
+</tr>
+<tr>
+<th>Rounding</th>
+<td>{{jsxref("Temporal/Instant/round", "round()")}}</td>
+<td>{{jsxref("Temporal/ZonedDateTime/round", "round()")}}</td>
+<td>{{jsxref("Temporal/PlainDateTime/round", "round()")}}</td>
+<td>N/A</td>
+<td>{{jsxref("Temporal/PlainTime/round", "round()")}}</td>
+<td>N/A</td>
+<td>N/A</td>
+</tr>
+<tr>
+<th>Comparison</th>
+<td>{{jsxref("Temporal/Instant/equals", "equals()")}}<br>{{jsxref("Temporal/Instant/compare", "Instant.compare()")}}</td>
+<td>{{jsxref("Temporal/ZonedDateTime/equals", "equals()")}}<br>{{jsxref("Temporal/ZonedDateTime/compare", "ZonedDateTime.compare()")}}</td>
+<td>{{jsxref("Temporal/PlainDateTime/equals", "equals()")}}<br>{{jsxref("Temporal/PlainDateTime/compare", "PlainDateTime.compare()")}}</td>
+<td>{{jsxref("Temporal/PlainDate/equals", "equals()")}}<br>{{jsxref("Temporal/PlainDate/compare", "PlainDate.compare()")}}</td>
+<td>{{jsxref("Temporal/PlainTime/equals", "equals()")}}<br>{{jsxref("Temporal/PlainTime/compare", "PlainTime.compare()")}}</td>
+<td>{{jsxref("Temporal/PlainYearMonth/equals", "equals()")}}<br>{{jsxref("Temporal/PlainYearMonth/compare", "PlainYearMonth.compare()")}}</td>
+<td>{{jsxref("Temporal/PlainMonthDay/equals", "equals()")}}</td>
+</tr>
+<tr>
+<th>Serialization</th>
+<td>{{jsxref("Temporal/Instant/toJSON", "toJSON()")}}<br>{{jsxref("Temporal/Instant/toLocaleString", "toLocaleString()")}}<br>{{jsxref("Temporal/Instant/toString", "toString()")}}<br>{{jsxref("Temporal/Instant/valueOf", "valueOf()")}}</td>
+<td>{{jsxref("Temporal/ZonedDateTime/toJSON", "toJSON()")}}<br>{{jsxref("Temporal/ZonedDateTime/toLocaleString", "toLocaleString()")}}<br>{{jsxref("Temporal/ZonedDateTime/toString", "toString()")}}<br>{{jsxref("Temporal/ZonedDateTime/valueOf", "valueOf()")}}</td>
+<td>{{jsxref("Temporal/PlainDateTime/toJSON", "toJSON()")}}<br>{{jsxref("Temporal/PlainDateTime/toLocaleString", "toLocaleString()")}}<br>{{jsxref("Temporal/PlainDateTime/toString", "toString()")}}<br>{{jsxref("Temporal/PlainDateTime/valueOf", "valueOf()")}}</td>
+<td>{{jsxref("Temporal/PlainDate/toJSON", "toJSON()")}}<br>{{jsxref("Temporal/PlainDate/toLocaleString", "toLocaleString()")}}<br>{{jsxref("Temporal/PlainDate/toString", "toString()")}}<br>{{jsxref("Temporal/PlainDate/valueOf", "valueOf()")}}</td>
+<td>{{jsxref("Temporal/PlainTime/toJSON", "toJSON()")}}<br>{{jsxref("Temporal/PlainTime/toLocaleString", "toLocaleString()")}}<br>{{jsxref("Temporal/PlainTime/toString", "toString()")}}<br>{{jsxref("Temporal/PlainTime/valueOf", "valueOf()")}}</td>
+<td>{{jsxref("Temporal/PlainYearMonth/toJSON", "toJSON()")}}<br>{{jsxref("Temporal/PlainYearMonth/toLocaleString", "toLocaleString()")}}<br>{{jsxref("Temporal/PlainYearMonth/toString", "toString()")}}<br>{{jsxref("Temporal/PlainYearMonth/valueOf", "valueOf()")}}</td>
+<td>{{jsxref("Temporal/PlainMonthDay/toJSON", "toJSON()")}}<br>{{jsxref("Temporal/PlainMonthDay/toLocaleString", "toLocaleString()")}}<br>{{jsxref("Temporal/PlainMonthDay/toString", "toString()")}}<br>{{jsxref("Temporal/PlainMonthDay/valueOf", "valueOf()")}}</td>
+</tr>
+</tbody>
+</table>
+
+The following table summarizes which properties are available on each class, giving you a sense of what information each class can represent.
+
+<table>
+<thead>
+<tr>
+<td></td>
+<th><code>Instant</code></th>
+<th><code>ZonedDateTime</code></th>
+<th><code>PlainDateTime</code></th>
+<th><code>PlainDate</code></th>
+<th><code>PlainTime</code></th>
+<th><code>PlainYearMonth</code></th>
+<th><code>PlainMonthDay</code></th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<th>Calendar</th>
+<td>N/A</td>
+<td>{{jsxref("Temporal/ZonedDateTime/calendarId", "calendarId")}}</td>
+<td>{{jsxref("Temporal/PlainDateTime/calendarId", "calendarId")}}</td>
+<td>{{jsxref("Temporal/PlainDate/calendarId", "calendarId")}}</td>
+<td>N/A</td>
+<td>{{jsxref("Temporal/PlainYearMonth/calendarId", "calendarId")}}</td>
+<td>{{jsxref("Temporal/PlainMonthDay/calendarId", "calendarId")}}</td>
+</tr>
+<tr>
+<th>Year-related</th>
+<td>N/A</td>
+<td>{{jsxref("Temporal/ZonedDateTime/era", "era")}}<br>{{jsxref("Temporal/ZonedDateTime/eraYear", "eraYear")}}<br>{{jsxref("Temporal/ZonedDateTime/year", "year")}}<br>{{jsxref("Temporal/ZonedDateTime/inLeapYear", "inLeapYear")}}<br>{{jsxref("Temporal/ZonedDateTime/monthsInYear", "monthsInYear")}}<br>{{jsxref("Temporal/ZonedDateTime/daysInYear", "daysInYear")}}</td>
+<td>{{jsxref("Temporal/PlainDateTime/era", "era")}}<br>{{jsxref("Temporal/PlainDateTime/eraYear", "eraYear")}}<br>{{jsxref("Temporal/PlainDateTime/year", "year")}}<br>{{jsxref("Temporal/PlainDateTime/inLeapYear", "inLeapYear")}}<br>{{jsxref("Temporal/PlainDateTime/monthsInYear", "monthsInYear")}}<br>{{jsxref("Temporal/PlainDateTime/daysInYear", "daysInYear")}}</td>
+<td>{{jsxref("Temporal/PlainDate/era", "era")}}<br>{{jsxref("Temporal/PlainDate/eraYear", "eraYear")}}<br>{{jsxref("Temporal/PlainDate/year", "year")}}<br>{{jsxref("Temporal/PlainDate/inLeapYear", "inLeapYear")}}<br>{{jsxref("Temporal/PlainDate/monthsInYear", "monthsInYear")}}<br>{{jsxref("Temporal/PlainDate/daysInYear", "daysInYear")}}</td>
+<td>N/A</td>
+<td>{{jsxref("Temporal/PlainYearMonth/era", "era")}}<br>{{jsxref("Temporal/PlainYearMonth/eraYear", "eraYear")}}<br>{{jsxref("Temporal/PlainYearMonth/year", "year")}}<br>{{jsxref("Temporal/PlainYearMonth/inLeapYear", "inLeapYear")}}<br>{{jsxref("Temporal/PlainYearMonth/monthsInYear", "monthsInYear")}}<br>{{jsxref("Temporal/PlainYearMonth/daysInYear", "daysInYear")}}</td>
+<td>N/A</td>
+</tr>
+<tr>
+<th>Month-related</th>
+<td>N/A</td>
+<td>{{jsxref("Temporal/ZonedDateTime/month", "month")}}<br>{{jsxref("Temporal/ZonedDateTime/monthCode", "monthCode")}}<br>{{jsxref("Temporal/ZonedDateTime/daysInMonth", "daysInMonth")}}</td>
+<td>{{jsxref("Temporal/PlainDateTime/month", "month")}}<br>{{jsxref("Temporal/PlainDateTime/monthCode", "monthCode")}}<br>{{jsxref("Temporal/PlainDateTime/daysInMonth", "daysInMonth")}}</td>
+<td>{{jsxref("Temporal/PlainDate/month", "month")}}<br>{{jsxref("Temporal/PlainDate/monthCode", "monthCode")}}<br>{{jsxref("Temporal/PlainDate/daysInMonth", "daysInMonth")}}</td>
+<td>N/A</td>
+<td>{{jsxref("Temporal/PlainYearMonth/month", "month")}}<br>{{jsxref("Temporal/PlainYearMonth/monthCode", "monthCode")}}<br>{{jsxref("Temporal/PlainYearMonth/daysInMonth", "daysInMonth")}}</td>
+<td>{{jsxref("Temporal/PlainMonthDay/monthCode", "monthCode")}}</td>
+</tr>
+<tr>
+<th>Week-related</th>
+<td>N/A</td>
+<td>{{jsxref("Temporal/ZonedDateTime/weekOfYear", "weekOfYear")}}<br>{{jsxref("Temporal/ZonedDateTime/yearOfWeek", "yearOfWeek")}}<br>{{jsxref("Temporal/ZonedDateTime/daysInWeek", "daysInWeek")}}</td>
+<td>{{jsxref("Temporal/PlainDateTime/weekOfYear", "weekOfYear")}}<br>{{jsxref("Temporal/PlainDateTime/yearOfWeek", "yearOfWeek")}}<br>{{jsxref("Temporal/PlainDateTime/daysInWeek", "daysInWeek")}}</td>
+<td>{{jsxref("Temporal/PlainDate/weekOfYear", "weekOfYear")}}<br>{{jsxref("Temporal/PlainDate/yearOfWeek", "yearOfWeek")}}<br>{{jsxref("Temporal/PlainDate/daysInWeek", "daysInWeek")}}</td>
+<td>N/A</td>
+<td>N/A</td>
+<td>N/A</td>
+</tr>
+<tr>
+<th>Day-related</th>
+<td>N/A</td>
+<td>{{jsxref("Temporal/ZonedDateTime/day", "day")}}<br>{{jsxref("Temporal/ZonedDateTime/dayOfWeek", "dayOfWeek")}}<br>{{jsxref("Temporal/ZonedDateTime/dayOfYear", "dayOfYear")}}</td>
+<td>{{jsxref("Temporal/PlainDateTime/day", "day")}}<br>{{jsxref("Temporal/PlainDateTime/dayOfWeek", "dayOfWeek")}}<br>{{jsxref("Temporal/PlainDateTime/dayOfYear", "dayOfYear")}}</td>
+<td>{{jsxref("Temporal/PlainDate/day", "day")}}<br>{{jsxref("Temporal/PlainDate/dayOfWeek", "dayOfWeek")}}<br>{{jsxref("Temporal/PlainDate/dayOfYear", "dayOfYear")}}</td>
+<td>N/A</td>
+<td>N/A</td>
+<td>{{jsxref("Temporal/PlainMonthDay/day", "day")}}</td>
+</tr>
+<tr>
+<th>Time components</th>
+<td>N/A</td>
+<td>{{jsxref("Temporal/ZonedDateTime/hour", "hour")}}<br>{{jsxref("Temporal/ZonedDateTime/minute", "minute")}}<br>{{jsxref("Temporal/ZonedDateTime/second", "second")}}<br>{{jsxref("Temporal/ZonedDateTime/millisecond", "millisecond")}}<br>{{jsxref("Temporal/ZonedDateTime/microsecond", "microsecond")}}<br>{{jsxref("Temporal/ZonedDateTime/nanosecond", "nanosecond")}}</td>
+<td>{{jsxref("Temporal/PlainDateTime/hour", "hour")}}<br>{{jsxref("Temporal/PlainDateTime/minute", "minute")}}<br>{{jsxref("Temporal/PlainDateTime/second", "second")}}<br>{{jsxref("Temporal/PlainDateTime/millisecond", "millisecond")}}<br>{{jsxref("Temporal/PlainDateTime/microsecond", "microsecond")}}<br>{{jsxref("Temporal/PlainDateTime/nanosecond", "nanosecond")}}</td>
+<td>N/A</td>
+<td>{{jsxref("Temporal/PlainTime/hour", "hour")}}<br>{{jsxref("Temporal/PlainTime/minute", "minute")}}<br>{{jsxref("Temporal/PlainTime/second", "second")}}<br>{{jsxref("Temporal/PlainTime/millisecond", "millisecond")}}<br>{{jsxref("Temporal/PlainTime/microsecond", "microsecond")}}<br>{{jsxref("Temporal/PlainTime/nanosecond", "nanosecond")}}</td>
+<td>N/A</td>
+<td>N/A</td>
+</tr>
+<tr>
+<th>Time zone</th>
+<td>N/A</td>
+<td>{{jsxref("Temporal/ZonedDateTime/timeZoneId", "timeZoneId")}}<br>{{jsxref("Temporal/ZonedDateTime/offset", "offset")}}<br>{{jsxref("Temporal/ZonedDateTime/offsetNanoseconds", "offsetNanoseconds")}}<br>{{jsxref("Temporal/ZonedDateTime/hoursInDay", "hoursInDay")}}<br>{{jsxref("Temporal/ZonedDateTime/getTimeZoneTransition", "getTimeZoneTransition()")}}<br>{{jsxref("Temporal/ZonedDateTime/startOfDay", "startOfDay()")}}</td>
+<td>N/A</td>
+<td>N/A</td>
+<td>N/A</td>
+<td>N/A</td>
+<td>N/A</td>
+</tr>
+<tr>
+<th>Epoch time</th>
+<td>{{jsxref("Temporal/Instant/epochMilliseconds", "epochMilliseconds")}}<br>{{jsxref("Temporal/Instant/epochNanoseconds", "epochNanoseconds")}}</td>
+<td>{{jsxref("Temporal/ZonedDateTime/epochMilliseconds", "epochMilliseconds")}}<br>{{jsxref("Temporal/ZonedDateTime/epochNanoseconds", "epochNanoseconds")}}</td>
+<td>N/A</td>
+<td>N/A</td>
+<td>N/A</td>
+<td>N/A</td>
+<td>N/A</td>
+</tr>
+</tbody>
+</table>
+
+### Conversion between classes
+
+The table below summarizes all conversion methods that exist on each class.
+
+<table>
+<tbody>
+<tr>
+<td rowspan="2" colspan="2"></td>
+<td colspan="7">How to convert from...</td>
+</tr>
+<tr>
+<th><code>Instant</code></th>
+<th><code>ZonedDateTime</code></th>
+<th><code>PlainDateTime</code></th>
+<th><code>PlainDate</code></th>
+<th><code>PlainTime</code></th>
+<th><code>PlainYearMonth</code></th>
+<th><code>PlainMonthDay</code></th>
+</tr>
+<tr><td rowspan="7">to...</td><th><code>Instant</code></th><td>/</td><td>{{jsxref("Temporal/ZonedDateTime/toInstant", "toInstant()")}}</td><td colspan="5">Convert to <code>ZonedDateTime</code> first</td></tr>
+<tr><th><code>ZonedDateTime</code></th><td>{{jsxref("Temporal/Instant/toZonedDateTimeISO", "toZonedDateTimeISO()")}}</td><td>/</td><td>{{jsxref("Temporal/PlainDateTime/toZonedDateTime", "toZonedDateTime()")}}</td><td>{{jsxref("Temporal/PlainDate/toZonedDateTime", "toZonedDateTime()")}}</td><td>{{jsxref("Temporal/PlainDate/toZonedDateTime", "PlainDate#toZonedDateTime()")}} (pass as argument)</td><td rowspan="2" colspan="2">Convert to <code>PlainDate</code> first</td></tr>
+<tr><th><code>PlainDateTime</code></th><td rowspan="5">Convert to <code>ZonedDateTime</code> first</td><td>{{jsxref("Temporal/ZonedDateTime/toPlainDateTime", "toPlainDateTime()")}}</td><td>/</td><td>{{jsxref("Temporal/PlainDate/toPlainDateTime", "toPlainDateTime()")}}</td><td>{{jsxref("Temporal/PlainDate/toPlainDateTime", "PlainDate#toPlainDateTime()")}} (pass as argument)</td></tr>
+<tr><th><code>PlainDate</code></th><td>{{jsxref("Temporal/ZonedDateTime/toPlainDate", "toPlainDate()")}}</td><td>{{jsxref("Temporal/PlainDateTime/toPlainDate", "toPlainDate()")}}</td><td>/</td><td>No overlap in information</td><td>{{jsxref("Temporal/PlainYearMonth/toPlainDate", "toPlainDate()")}}</td><td>{{jsxref("Temporal/PlainMonthDay/toPlainDate", "toPlainDate()")}}</td></tr>
+<tr><th><code>PlainTime</code></th><td>{{jsxref("Temporal/ZonedDateTime/toPlainTime", "toPlainTime()")}}</td><td>{{jsxref("Temporal/PlainDateTime/toPlainTime", "toPlainTime()")}}</td><td>No overlap in information</td><td>/</td><td colspan="2">No overlap in information</td></tr>
+<tr><th><code>PlainYearMonth</code></th><td rowspan="2" colspan="2">Convert to <code>PlainDate</code> first</td><td>{{jsxref("Temporal/PlainDate/toPlainYearMonth", "toPlainYearMonth()")}}</td><td rowspan="2">No overlap in information</td><td>/</td><td>Convert to <code>PlainDate</code> first</td></tr>
+<tr><th><code>PlainMonthDay</code></th><td>{{jsxref("Temporal/PlainDate/toPlainMonthDay", "toPlainMonthDay()")}}</td><td>Convert to <code>PlainDate</code> first</td><td>/</td></tr>
+</tbody>
+</table>
+
+With these tables, you should have a basic idea of how to navigate the `Temporal` API.
+
+### Calendars
+
+A calendar is a way to organize days, typically into periods of weeks, months, years, and eras. Most of the world uses the Gregorian calendar, but there are many other calendars in use, especially in religious and cultural contexts. By default, all calendar-aware `Temporal` objects use the ISO 8601 calendar system, which is based on the Gregorian calendar and defines additional week-numbering rules. {{jsxref("Intl/Locale/getCalendars", "Intl.Locale.prototype.getCalendars()")}} lists most of the calendars likely to be supported by browsers. Here we provide a brief overview of how calendar systems are formed to help you internalize what factors may vary between calendars.
+
+There are three prominent periodic events on Earth: its rotation around the sun (365.242 days for one revolution), the moon's rotation around the Earth (29.53 days from new moon to new moon), and its rotation around its axis (24 hours from sunrise to sunrise). Every culture has the same measure of a "day", which is 24 hours. Occasional changes such as daylight saving time are not part of the calendar, but are part of the [time zone](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#time_zones_and_offsets)'s information.
+
+- Some calendars primarily define one year as 365.242 days on average, by defining years to have 365 days, and adding an extra day, the _leap day_, about every 4 years. Then, the year may be further divided into parts called months. These calendars are called _solar calendars_. The Gregorian calendar and the Solar Hijri calendar are solar calendars.
+- Some calendars primarily define one month as 29.5 days on average, by defining months to alternate between 29 and 30 days. Then, 12 months may be grouped into a year of 354 days. These calendars are called _lunar calendars_. The Islamic calendar is a lunar calendar. Because a lunar year is artificial and does not correlate with the season cycle, lunar calendars are generally rarer.
+- Some calendars also primarily define months based on lunar cycles, like lunar calendars. Then, to compensate for the 11-day discrepancy with the solar year, an extra month, the _leap month_, is added about every 3 years. These calendars are called _lunisolar calendars_. The Hebrew calendar and the Chinese calendar are lunisolar calendars.
+
+In `Temporal`, every date under one calendar system is uniquely identified by three components: `year`, `month`, and `day`. `year` is an integer that may be zero or negative, which increases monotonously with time. The year `1` (or `0`, if it exists) is known as the calendar epoch, and is arbitrary for each calendar. `month` is an integer that increments by 1 every time, starting at `1` and ending at `date.monthsInYear`, then resetting back to `1` as the year advances. `day` is also a positive integer, but it may not start at 1 or increment by 1 every time, because political changes may cause days to be skipped or repeated. But in general, `day` monotonously increases and resets as the month advances.
+
+In addition to `year`, a year can also be uniquely identified by the combination of `era` and `eraYear`, for calendars that use eras. For example, the Gregorian calendar uses the era "CE" (Common Era) and "BCE" (Before Common Era), and the year `-1` is the same as `{ era: "bce", eraYear: 1 }`. `era` is a lowercase string, and `eraYear` is an arbitrary integer that may be zero or negative, or even decrease with time (usually for the oldest era).
+
+> [!NOTE]
+> Always use `era` and `eraYear` as a pair; don't use one property without also using the other. In addition, to avoid conflicts, don't combine `year` and `era`/`eraYear` when designating a year. Pick one year representation and use it consistently.
+>
+> Be careful of the following incorrect assumptions about years:
+>
+> - Don't assume that `era` and `eraYear` are always present; they may be `undefined`.
+> - Don't assume that `era` is a user-friendly string; use `toLocaleString()` to format your date instead.
+> - Don't assume that two `year` values from different calendars are comparable; use the `compare()` static method instead.
+> - Don't assume that years have 365/366 days and 12 months; use `daysInYear` and `monthsInYear` instead.
+> - Don't assume that leap years (`inLeapYear` is `true`) have one extra day; they may have an extra month.
+
+In addition to `month`, a month in a year can also be uniquely identified by the `monthCode`. `monthCode` usually maps to the month's name, but `month` does not. For example, in the case of lunisolar calendars, two months with the same `monthCode`, where one belongs to a leap year and the other one does not, will have different `month` values if they come after the leap month, due to the insertion of an extra month.
+
+> [!NOTE]
+> To avoid conflicts, don't combine `month` and `monthCode` when designating a month. Pick one month representation and use it consistently. `month` is more useful if you need the order of months in a year (e.g., when looping through the months), while `monthCode` is more useful if you need the name of the month (e.g., when storing birthdays).
+>
+> Be careful of the following incorrect assumptions about months:
+>
+> - Don't assume that `monthCode` and `month` always correspond.
+> - Don't assume the number of days in a month; use `daysInMonth` instead.
+> - Don't assume that `monthCode` is a user-friendly string; use `toLocaleString()` to format your date instead.
+> - Generally, don't cache the name of months in an array or object. Even though `monthCode` usually maps to the month's name within one calendar, we recommend always computing the month's name using, for example, `date.toLocaleString("en-US", { calendar: date.calendarId, month: "long" })`.
+
+In addition to `day` (which is a month-based index), a day in a year can also be uniquely identified by the `dayOfYear`. `dayOfYear` is a positive integer that increments by 1 every time, starting at `1` and ending at `date.daysInYear`.
+
+The concept of a "week" is not connected with any astronomical event, but is a cultural construct. Therefore, weeks can have 4, 5, 6, 8, or more days, or not even a fixed number of days. To get the specific number of days of the week of a date, use the date's `daysInWeek`. `Temporal` identifies weeks by the combination of `weekOfYear` and `yearOfWeek`. `weekOfYear` is a positive integer that increments by 1 every time, starting at `1`, then resetting back to `1` as the year advances. `yearOfWeek` is generally the same as `year`, but may be different at the start or end of each year, because one week may cross two years, and `yearOfWeek` picks one of the two years based on the calendar's rules.
+
+> [!NOTE]
+> Always use `weekOfYear` and `yearOfWeek` as a pair; don't use `weekOfYear` and `year`.
+>
+> Be careful of the following incorrect assumptions about weeks:
+>
+> - Don't assume that `weekOfYear` and `yearOfWeek` are always present; they may be `undefined`.
+> - Don't assume that weeks are always 7 days long; use `daysInWeek` instead.
+> - Note that the current `Temporal` API does not support year-week dates, so you can't construct dates using these properties or serialize dates to year-week representations. They are only informational properties.
+
+### RFC 9557 format
+
+All `Temporal` classes can be serialized and deserialized using the format specified in [RFC 9557](https://datatracker.ietf.org/doc/html/rfc9557), which is based on [ISO 8601 / RFC 3339](https://datatracker.ietf.org/doc/html/rfc3339). The format, in its full form, is as follows (spaces are only for readability and should not be present in the actual string):
+
+```plain
+YYYY-MM-DD T HH:mm:ss.sssssssss Z/±HH:mm:ss.sssssssss [time_zone_id] [u-ca=calendar_id]
+```
+
+Different classes have different requirements for the presence of each component, so you will find a section titled "RFC 9557 format" in each class's documentation, which specifies the format recognized by that class.
+
+This is very similar to the [date time string format](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date#date_time_string_format) used by {{jsxref("Date")}}, which is also based on ISO 8601. The main addition is the ability to specify micro- and nanosecond components, and the ability to specify the time zone and calendar system.
+
+## Static properties
+
+- {{jsxref("Temporal.Duration")}} {{experimental_inline}}
+  - : Represents a difference between two time points, which can be used in date/time arithmetic. It is fundamentally represented as a combination of years, months, weeks, days, hours, minutes, seconds, milliseconds, microseconds, and nanoseconds values.
+- {{jsxref("Temporal.Instant")}} {{experimental_inline}}
+  - : Represents a unique point in history, with nanosecond precision. It is fundamentally represented as the number of nanoseconds since the Unix epoch (midnight at the beginning of January 1, 1970, UTC), without any time zone or calendar system.
+- {{jsxref("Temporal.Now")}} {{experimental_inline}}
+  - : Provides methods for getting the current time in various formats.
+- {{jsxref("Temporal.PlainDate")}} {{experimental_inline}}
+  - : Represents a calendar date (a date without a time or time zone); for example, an event on a calendar which happens during the whole day no matter which time zone it's happening in. It is fundamentally represented as an ISO 8601 calendar date, with year, month, and day fields, and an associated calendar system.
+- {{jsxref("Temporal.PlainDateTime")}} {{experimental_inline}}
+  - : Represents a date (calendar date) and time (wall-clock time) without a time zone. It is fundamentally represented as a combination of a [date](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate) (with an associated calendar system) and a [time](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainTime).
+- {{jsxref("Temporal.PlainMonthDay")}} {{experimental_inline}}
+  - : Represents the month and day of a calendar date, without a year or time zone; for example, an event on a calendar that recurs every year and happens during the whole day. It is fundamentally represented as an ISO 8601 calendar date, with year, month, and day fields, and an associated calendar system. The year is used to disambiguate the month-day in non-ISO calendar systems.
+- {{jsxref("Temporal.PlainTime")}} {{experimental_inline}}
+  - : Represents a time without a date or time zone; for example, a recurring event that happens at the same time every day. It is fundamentally represented as a combination of hour, minute, second, millisecond, microsecond, and nanosecond values.
+- {{jsxref("Temporal.PlainYearMonth")}} {{experimental_inline}}
+  - : Represents the year and month of a calendar date, without a day or time zone; for example, an event on a calendar that happens during the whole month. It is fundamentally represented as an ISO 8601 calendar date, with year, month, and day fields, and an associated calendar system. The day is used to disambiguate the year-month in non-ISO calendar systems.
+- {{jsxref("Temporal.ZonedDateTime")}} {{experimental_inline}}
+  - : Represents a date and time with a time zone. It is fundamentally represented as a combination of an [instant](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Instant), a time zone, and a calendar system.
+- `Temporal[Symbol.toStringTag]`
+  - : The initial value of the [`[Symbol.toStringTag]`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol/toStringTag) property is the string `"Temporal"`. This property is used in {{jsxref("Object.prototype.toString()")}}.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Intl.DateTimeFormat")}}
+- {{jsxref("Intl.RelativeTimeFormat")}}
+- {{jsxref("Intl.DurationFormat")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/instant/add/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/instant/add/index.md
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+---
+title: Temporal.Instant.prototype.add()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Instant/add
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Instant.add
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`add()`** method of {{jsxref("Temporal.Instant")}} instances returns a new `Temporal.Instant` object representing this instant moved forward by a given duration (in a form convertible by {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}).
+
+## Syntax
+
+```js-nolint
+add(duration)
+```
+
+### Parameters
+
+- `duration`
+  - : A string, an object, or a {{jsxref("Temporal.Duration")}} instance representing a duration to add to this instant. It is converted to a `Temporal.Duration` object using the same algorithm as {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}.
+
+### Return value
+
+A new {{jsxref("Temporal.Instant")}} object representing adding `duration` to this instant. If `duration` is positive, then the returned instant is later than this instant; if `duration` is negative, then the returned instant is earlier than this instant.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown in one of the following cases:
+    - `duration` is a [calendar duration](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#calendar_durations) (it has a non-zero `years`, `months`, or `weeks`), or has a non-zero `days`, because calendar durations are ambiguous without a calendar and time reference.
+    - The sum of `this` and `duration` overflows the maximum or underflows the minimum representable instant, which is ±10<sup>8</sup> days (about ±273,972.6 years).
+
+## Description
+
+In essence, the `add()` method first gets the number of nanoseconds represented by `duration`, adds it to this instant's {{jsxref("Temporal/Instant/epochNanoseconds", "epochNanoseconds")}}, and then creates a new `Temporal.Instant` object from the result. Therefore, the duration must unambiguously represent a fixed amount of time.
+
+If you want to add a calendar duration, the addition must be performed in the context of a calendar and a time zone to account for the variable lengths of months, years, and days (because of daylight saving time). In this case, convert the instant to a {{jsxref("Temporal.ZonedDateTime")}} object, add the duration, and then convert the result back to an instant.
+
+Adding a duration is equivalent to [subtracting](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Instant/subtract) its [negation](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration/negated).
+
+## Examples
+
+### Adding a Temporal.Duration
+
+```js
+const instant = Temporal.Instant.fromEpochMilliseconds(0);
+const duration = Temporal.Duration.from("PT1S");
+const newInstant = instant.add(duration);
+console.log(newInstant.epochMilliseconds); // 1000
+```
+
+### Adding an object or a string
+
+```js
+const instant = Temporal.Instant.fromEpochMilliseconds(0);
+const newInstant = instant.add({ seconds: 1 });
+console.log(newInstant.epochMilliseconds); // 1000
+
+const newInstant2 = instant.add("PT1S");
+console.log(newInstant2.epochMilliseconds); // 1000
+```
+
+### Adding a calendar duration
+
+```js
+const instant = Temporal.Instant.fromEpochMilliseconds(1730610000000);
+const duration = Temporal.Duration.from({ days: 1 });
+
+// This instant is 2024-11-03T01:00:00-04:00[America/New_York],
+// which is a DST transition day in the US.
+const instant2 = instant
+  .toZonedDateTimeISO("America/New_York")
+  .add(duration)
+  .toInstant();
+console.log(instant2.epochMilliseconds); // 1730700000000
+
+// The same instant is not a DST transition day in Paris.
+const instant3 = instant
+  .toZonedDateTimeISO("Europe/Paris")
+  .add(duration)
+  .toInstant();
+console.log(instant3.epochMilliseconds); // 1730696400000
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Instant")}}
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/Instant/subtract", "Temporal.Instant.prototype.subtract()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/instant/compare/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/instant/compare/index.md
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@@ -0,0 +1,72 @@
+---
+title: Temporal.Instant.compare()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Instant/compare
+page-type: javascript-static-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Instant.compare
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.Instant.compare()`** static method returns a number (-1, 0, or 1) indicating whether the first instant comes before, is the same as, or comes after the second instant. It is equivalent to comparing the {{jsxref("Temporal/Instant/epochNanoseconds", "epochNanoseconds")}} of the two instants.
+
+## Syntax
+
+```js-nolint
+Temporal.Instant.compare(instant1, instant2)
+```
+
+### Parameters
+
+- `instant1`
+  - : A string or a {{jsxref("Temporal.Instant")}} instance representing the first instant to compare. It is converted to a `Temporal.Instant` object using the same algorithm as {{jsxref("Temporal/Instant/from", "Temporal.Instant.from()")}}.
+- `instant2`
+  - : The second instant to compare, converted to a `Temporal.Instant` object using the same algorithm as `instant1`.
+
+### Return value
+
+Returns `-1` if `instant1` comes before `instant2`, `0` if they are the same, and `1` if `instant1` comes after.
+
+## Examples
+
+### Using Temporal.Instant.compare()
+
+```js
+const instant1 = Temporal.Instant.from("2021-08-01T12:34:56Z");
+const instant2 = Temporal.Instant.from("2021-08-01T12:34:56Z");
+
+console.log(Temporal.Instant.compare(instant1, instant2)); // 0
+
+const instant3 = Temporal.Instant.from("2021-08-01T13:34:56Z");
+console.log(Temporal.Instant.compare(instant1, instant3)); // -1
+```
+
+### Sorting an array of instants
+
+The purpose of this `compare()` function is to act as a comparator to be passed to {{jsxref("Array.prototype.sort()")}} and related functions.
+
+```js
+const instants = [
+  Temporal.Instant.from("2021-08-01T12:34:56Z"),
+  Temporal.Instant.from("2021-08-01T12:34:56+01:00"),
+  Temporal.Instant.from("2021-08-01T12:34:56-01:00"),
+];
+
+instants.sort(Temporal.Instant.compare);
+console.log(instants.map((instant) => instant.toString()));
+// [ '2021-08-01T11:34:56Z', '2021-08-01T12:34:56Z', '2021-08-01T13:34:56Z' ]
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Instant")}}
+- {{jsxref("Temporal/Instant/equals", "Temporal.Instant.prototype.equals()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/instant/epochmilliseconds/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/instant/epochmilliseconds/index.md
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--- /dev/null
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+---
+title: Temporal.Instant.prototype.epochMilliseconds
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Instant/epochMilliseconds
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Instant.epochMilliseconds
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`epochMilliseconds`** accessor property of {{jsxref("Temporal.Instant")}} instances returns an integer representing the number of milliseconds elapsed since the Unix epoch (midnight at the beginning of January 1, 1970, UTC) to this instant. It is equivalent to dividing `epochNanoseconds` by `1e6` and flooring the result.
+
+The set accessor of `epochMilliseconds` is `undefined`. You cannot change this property directly. To create a new `Temporal.Instant` object with the desired new `epochMilliseconds` value, use the {{jsxref("Temporal/Instant/add", "add()")}} or {{jsxref("Temporal/Instant/subtract", "subtract()")}} method with the appropriate duration.
+
+## Examples
+
+### Using epochMilliseconds
+
+```js
+const instant = Temporal.Instant.from("2021-08-01T12:34:56.789Z");
+console.log(instant.epochMilliseconds); // 1627821296789
+
+const instant2 = Temporal.Instant.from("1969-08-01T12:34:56.789Z");
+console.log(instant2.epochMilliseconds); // -13173903211
+```
+
+### Changing epochMilliseconds
+
+This is the method that allows you to move by any amount of time:
+
+```js
+const instant = Temporal.Instant.from("2021-08-01T12:34:56.789Z");
+const instant1hourLater = instant.add({ hours: 1 });
+console.log(instant1hourLater.epochMilliseconds); // 1627824896789
+```
+
+If you already know the change in milliseconds, you can also directly construct a new `Temporal.Instant` object:
+
+```js
+const instant = Temporal.Instant.from("2021-08-01T12:34:56.789Z");
+const instant1hourLater = Temporal.Instant.fromEpochMilliseconds(
+  instant.epochMilliseconds + 3600000,
+);
+console.log(instant1hourLater.epochMilliseconds); // 1627824896789
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Instant")}}
+- {{jsxref("Temporal/Instant/epochNanoseconds", "Temporal.Instant.prototype.epochNanoseconds")}}
+- {{jsxref("Temporal/Instant/fromEpochMilliseconds", "Temporal.Instant.fromEpochMilliseconds()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/instant/epochnanoseconds/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/instant/epochnanoseconds/index.md
new file mode 100644
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@@ -0,0 +1,62 @@
+---
+title: Temporal.Instant.prototype.epochNanoseconds
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Instant/epochNanoseconds
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Instant.epochNanoseconds
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`epochNanoseconds`** accessor property of {{jsxref("Temporal.Instant")}} instances returns a {{jsxref("BigInt")}} representing the number of nanoseconds elapsed since the Unix epoch (midnight at the beginning of January 1, 1970, UTC) to this instant.
+
+The set accessor of `epochNanoseconds` is `undefined`. You cannot change this property directly. To create a new `Temporal.Instant` object with the desired new `epochNanoseconds` value, use the {{jsxref("Temporal/Instant/add", "add()")}} or {{jsxref("Temporal/Instant/subtract", "subtract()")}} method with the appropriate duration.
+
+An instant can only represent ±10<sup>8</sup> days (about ±273,972.6 years) around the epoch, which is ±8.64e21 nanoseconds. Attempting to set `epochNanosecond` beyond this boundary throws a {{jsxref("RangeError")}}.
+
+## Examples
+
+### Using epochNanoseconds
+
+```js
+const instant = Temporal.Instant.from("2021-08-01T12:34:56.789Z");
+console.log(instant.epochNanoseconds); // 1627821296789000000n
+
+const instant2 = Temporal.Instant.from("1969-08-01T12:34:56.789Z");
+console.log(instant2.epochNanoseconds); // -13173903211000000n
+```
+
+### Changing epochNanoseconds
+
+This is the method that allows you to move by any amount of time:
+
+```js
+const instant = Temporal.Instant.from("2021-08-01T12:34:56.789Z");
+const instant1hourLater = instant.add({ hours: 1 });
+console.log(instant1hourLater.epochNanoseconds); // 1627824896789000000n
+```
+
+If you already know the change in nanoseconds, you can also directly construct a new `Temporal.Instant` object:
+
+```js
+const instant = Temporal.Instant.from("2021-08-01T12:34:56.789Z");
+const instant1hourLater = Temporal.Instant.fromEpochNanoseconds(
+  instant.epochNanoseconds + 3600000000000n,
+);
+console.log(instant1hourLater.epochNanoseconds); // 1627824896789000000n
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Instant")}}
+- {{jsxref("Temporal/Instant/epochMilliseconds", "Temporal.Instant.prototype.epochMilliseconds")}}
+- {{jsxref("Temporal/Instant/fromEpochNanoseconds", "Temporal.Instant.fromEpochNanoseconds()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/instant/equals/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/instant/equals/index.md
new file mode 100644
index 000000000000000..c0d199f39dbc3dd
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/instant/equals/index.md
@@ -0,0 +1,50 @@
+---
+title: Temporal.Instant.prototype.equals()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Instant/equals
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Instant.equals
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`equals()`** method of {{jsxref("Temporal.Instant")}} instances returns `true` if this instant is equivalent in value to another instant (in a form convertible by {{jsxref("Temporal/Instant/from", "Temporal.Instant.from()")}}), and `false` otherwise. They are compared by their {{jsxref("Temporal/Instant/epochNanoseconds", "epochNanoseconds")}}. It is equivalent to `Temporal.Instant.compare(this, other) === 0`.
+
+## Syntax
+
+```js-nolint
+equals(other)
+```
+
+### Parameters
+
+- `other`
+  - : A string or a {{jsxref("Temporal.Instant")}} instance representing the other instant to compare. It is converted to a `Temporal.Instant` object using the same algorithm as {{jsxref("Temporal/Instant/from", "Temporal.Instant.from()")}}.
+
+### Return value
+
+`true` if this instant is equal to `other` by nanoseconds, `false` otherwise.
+
+## Examples
+
+### Using equals()
+
+```js
+const instant1 = Temporal.Instant.from("2021-08-01T12:34:56Z");
+const instant2 = Temporal.Instant.fromEpochMilliseconds(1627821296000);
+console.log(instant1.equals(instant2)); // true
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Instant")}}
+- {{jsxref("Temporal/Instant/compare", "Temporal.Instant.compare()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/instant/from/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/instant/from/index.md
new file mode 100644
index 000000000000000..449403fd28f592e
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/instant/from/index.md
@@ -0,0 +1,74 @@
+---
+title: Temporal.Instant.from()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Instant/from
+page-type: javascript-static-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Instant.from
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.Instant.from()`** static method creates a new `Temporal.Instant` object from another `Temporal.Instant` object, or an [RFC 9557](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Instant#rfc_9557_format) string.
+
+## Syntax
+
+```js-nolint
+Temporal.Instant.from(info)
+```
+
+### Parameters
+
+- `info`
+  - : One of the following:
+    - A {{jsxref("Temporal.Instant")}} instance, which creates a copy of the instance.
+    - An [RFC 9557](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Instant#rfc_9557_format) string containing a date, time, and time zone offset. The time zone name is ignored; only the offset is used.
+
+### Return value
+
+A new `Temporal.Instant` object representing the instant in time specified by `info`.
+
+### Exceptions
+
+- {{jsxref("TypeError")}}
+  - : Thrown if `info` is not a `Temporal.Instant` instance or a string.
+- {{jsxref("RangeError")}}
+  - : Thrown if the string is not a valid RFC 9557 string, or if the date and time are outside the range of representable instants (±10<sup>8</sup> days, or about ±273,972.6 years).
+
+## Examples
+
+### Creating an instant from a string
+
+```js
+const instant = Temporal.Instant.from("1970-01-01T00Z");
+console.log(instant.toString()); // 1970-01-01T00:00:00Z
+
+const instant2 = Temporal.Instant.from("1970-01-01T00+08:00");
+console.log(instant.toString()); // 1969-12-31T16:00:00Z
+
+// America/New_York is UTC-5 in January 1970, not UTC+8
+const instant3 = Temporal.Instant.from("1970-01-01T00+08:00[America/New_York]");
+console.log(instant.toString()); // 1969-12-31T16:00:00Z; the time zone name is ignored
+```
+
+### Creating an instant from another instant
+
+```js
+const instant = Temporal.Instant.from("1970-01-01T00Z");
+const instant2 = Temporal.Instant.from(instant);
+console.log(instant2.toString()); // 1970-01-01T00:00:00Z
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Instant")}}
+- {{jsxref("Temporal/Instant/fromEpochMilliseconds", "Temporal.Instant.fromEpochMilliseconds()")}}
+- {{jsxref("Temporal/Instant/fromEpochNanoseconds", "Temporal.Instant.fromEpochNanoseconds()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/instant/fromepochmilliseconds/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/instant/fromepochmilliseconds/index.md
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+---
+title: Temporal.Instant.fromEpochMilliseconds()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Instant/fromEpochMilliseconds
+page-type: javascript-static-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Instant.fromEpochMilliseconds
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.Instant.fromEpochMilliseconds()`** static method creates a new `Temporal.Instant` object from the number of milliseconds since the Unix epoch (midnight at the beginning of January 1, 1970, UTC).
+
+To convert a {{jsxref("Date")}} object to a `Temporal.Instant` object, use {{jsxref("Date.prototype.toTemporalInstant()")}} instead.
+
+## Syntax
+
+```js-nolint
+Temporal.Instant.fromEpochMilliseconds(epochMilliseconds)
+```
+
+### Parameters
+
+- `epochMilliseconds`
+  - : A number representing the number of milliseconds since the Unix epoch. Internally, it is converted to a BigInt and multiplied by `1e6` to get the number of nanoseconds.
+
+### Return value
+
+A new `Temporal.Instant` object representing the instant in time specified by `epochMilliseconds`.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown if `epochMilliseconds` is outside the range of a representable instant, which is ±10<sup>8</sup> days (±8.64e15 milliseconds, or about ±273,972.6 years), or if it cannot be converted to a BigInt (e.g., not an integer).
+
+## Examples
+
+### Using Temporal.Instant.fromEpochMilliseconds()
+
+```js
+const instant = Temporal.Instant.fromEpochMilliseconds(0);
+console.log(instant.toString()); // 1970-01-01T00:00:00Z
+const vostok1Liftoff = Temporal.Instant.fromEpochMilliseconds(-275248380000);
+console.log(vostok1Liftoff.toString()); // 1961-04-12T06:07:00Z
+const sts1Liftoff = Temporal.Instant.fromEpochMilliseconds(355924804000);
+console.log(sts1Liftoff.toString()); // 1981-04-12T12:00:04Z
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Instant")}}
+- {{jsxref("Temporal/Instant/epochMilliseconds", "Temporal.Instant.prototype.epochMilliseconds")}}
+- {{jsxref("Temporal/Instant/from", "Temporal.Instant.from()")}}
+- {{jsxref("Temporal/Instant/fromEpochNanoseconds", "Temporal.Instant.fromEpochNanoseconds()")}}
+- {{jsxref("Date.prototype.toTemporalInstant()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/instant/fromepochnanoseconds/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/instant/fromepochnanoseconds/index.md
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+---
+title: Temporal.Instant.fromEpochNanoseconds()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Instant/fromEpochNanoseconds
+page-type: javascript-static-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Instant.fromEpochNanoseconds
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.Instant.fromEpochNanoseconds()`** static method creates a new `Temporal.Instant` object from the number of nanoseconds since the Unix epoch (midnight at the beginning of January 1, 1970, UTC).
+
+To convert a {{jsxref("Date")}} object to a `Temporal.Instant` object, use {{jsxref("Date.prototype.toTemporalInstant()")}} instead.
+
+## Syntax
+
+```js-nolint
+Temporal.Instant.fromEpochNanoseconds(epochNanoseconds)
+```
+
+### Parameters
+
+- `epochNanoseconds`
+  - : A [BigInt](/en-US/docs/Web/JavaScript/Reference/Global_Objects/BigInt) representing the number of nanoseconds since the Unix epoch.
+
+### Return value
+
+A new `Temporal.Instant` object representing the instant in time specified by `epochNanoseconds`.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown if `epochNanoseconds` is outside the range of a representable instant, which is ±10<sup>8</sup> days (±8.64e21 nanoseconds, or about ±273,972.6 years).
+
+## Examples
+
+### Using Temporal.Instant.fromEpochNanoseconds()
+
+```js
+const instant = Temporal.Instant.fromEpochNanoseconds(0n);
+console.log(instant.toString()); // 1970-01-01T00:00:00Z
+const vostok1Liftoff =
+  Temporal.Instant.fromEpochNanoseconds(-275248380000000000n);
+console.log(vostok1Liftoff.toString()); // 1961-04-12T06:07:00Z
+const sts1Liftoff = Temporal.Instant.fromEpochNanoseconds(355924804000000000n);
+console.log(sts1Liftoff.toString()); // 1981-04-12T12:00:04Z
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Instant")}}
+- {{jsxref("Temporal/Instant/epochNanoseconds", "Temporal.Instant.prototype.epochNanoseconds")}}
+- {{jsxref("Temporal/Instant/from", "Temporal.Instant.from()")}}
+- {{jsxref("Temporal/Instant/fromEpochMilliseconds", "Temporal.Instant.fromEpochMilliseconds()")}}
+- {{jsxref("Date.prototype.toTemporalInstant()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/instant/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/instant/index.md
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+---
+title: Temporal.Instant
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Instant
+page-type: javascript-class
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Instant
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.Instant`** object represents a unique point in history, with nanosecond precision. It is fundamentally represented as the number of nanoseconds since the Unix epoch (midnight at the beginning of January 1, 1970, UTC), without any time zone or calendar system.
+
+## Description
+
+`Temporal.Instant` is semantically the same as {{jsxref("Date")}}. They both encapsulate a single point in time, but `Temporal.Instant` is more precise because it stores nanoseconds rather than milliseconds. `Temporal.Instant` also avoids pitfalls of `Date` because it does not assume any calendar or time zone information—if you want to read any date or time information such as year or month, you need to convert it to a {{jsxref("Temporal.ZonedDateTime")}} first, using {{jsxref("Temporal/Instant/toZonedDateTimeISO()", "toZonedDateTimeISO()")}}.
+
+You can convert from `Date` to `Temporal.Instant` using the {{jsxref("Date.prototype.toTemporalInstant()")}} method, which should be preferred over other methods such as `Temporal.Instant.fromEpochMilliseconds()` because the former involves less user code and may be more optimized. You can also convert from `Temporal.Instant` to `Date` using its epoch milliseconds, such as `new Date(instant.epochMilliseconds)`.
+
+### RFC 9557 format
+
+`Instant` objects can be serialized and parsed using the [RFC 9557](https://datatracker.ietf.org/doc/html/rfc9557) format, an extension to the [ISO 8601 / RFC 3339](https://datatracker.ietf.org/doc/html/rfc3339) format. The string has the following form (spaces are only for readability and should not be present in the actual string):
+
+```plain
+YYYY-MM-DD T HH:mm:ss.sssssssss Z/±HH:mm:ss.sssssssss
+```
+
+- `YYYY`
+  - : Either a four-digit number, or a six-digit number with a `+` or `-` sign.
+- `MM`
+  - : A two-digit number from `01` to `12`.
+- `DD`
+  - : A two-digit number from `01` to `31`. The `YYYY`, `MM`, and `DD` components can be separated by `-` or nothing.
+- `T`
+  - : The date-time separator, which can be `T`, `t`, or a space.
+- `HH`
+  - : A two-digit number from `00` to `23`.
+- `mm` {{optional_inline}}
+  - : A two-digit number from `00` to `59`. Defaults to `00`.
+- `ss.sssssssss` {{optional_inline}}
+  - : A two-digit number from `00` to `59`. May optionally be followed by a `.` or `,` and one to nine digits. Defaults to `00`. The `HH`, `mm`, and `ss` components can be separated by `:` or nothing. You can omit either just `ss` or both `ss` and `mm`, so the time can be one of three forms: `HH`, `HH:mm`, or `HH:mm:ss.sssssssss`.
+- `Z/±HH:mm:ss.sssssssss`
+  - : Either the UTC designator `Z` or `z`, or an offset from UTC in the form `+` or `-` followed by the same format as the time component. Note that subminute precision may be unsupported by other systems. If an offset is provided, the time is interpreted in the specified offset.
+
+As an input, you may optionally include the time zone identifier and calendar, in the same format as [`ZonedDateTime`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#rfc_9557_format), but they will be ignored. Other annotations in the `[key=value]` format are also ignored, and they must not have the critical flag.
+
+When serializing, you can configure the fractional second digits and offset.
+
+## Constructor
+
+- {{jsxref("Temporal/Instant/Instant", "Temporal.Instant()")}} {{experimental_inline}}
+  - : Creates a new `Temporal.Instant` object by directly supplying the underlying data.
+
+## Static methods
+
+- {{jsxref("Temporal/Instant/compare", "Temporal.Instant.compare()")}} {{experimental_inline}}
+  - : Returns a number (-1, 0, or 1) indicating whether the first instant comes before, is the same as, or comes after the second instant. Equivalent to comparing the {{jsxref("Temporal/Instant/epochNanoseconds", "epochNanoseconds")}} of the two instants.
+- {{jsxref("Temporal/Instant/from", "Temporal.Instant.from()")}} {{experimental_inline}}
+  - : Creates a new `Temporal.Instant` object from another `Temporal.Instant` object, or an [RFC 9557](#rfc_9557_format) string.
+- {{jsxref("Temporal/Instant/fromEpochMilliseconds", "Temporal.Instant.fromEpochMilliseconds()")}} {{experimental_inline}}
+  - : Creates a new `Temporal.Instant` object from the number of milliseconds since the Unix epoch (midnight at the beginning of January 1, 1970, UTC).
+- {{jsxref("Temporal/Instant/fromEpochNanoseconds", "Temporal.Instant.fromEpochNanoseconds()")}} {{experimental_inline}}
+  - : Creates a new `Temporal.Instant` object from the number of nanoseconds since the Unix epoch (midnight at the beginning of January 1, 1970, UTC).
+
+## Instance properties
+
+These properties are defined on `Temporal.Instant.prototype` and shared by all `Temporal.Instant` instances.
+
+- {{jsxref("Object/constructor", "Temporal.Instant.prototype.constructor")}}
+  - : The constructor function that created the instance object. For `Temporal.Instant` instances, the initial value is the {{jsxref("Temporal/Instant/Instant", "Temporal.Instant()")}} constructor.
+- {{jsxref("Temporal/Instant/epochMilliseconds", "Temporal.Instant.prototype.epochMilliseconds")}} {{experimental_inline}}
+  - : Returns an integer representing the number of milliseconds elapsed since the Unix epoch (midnight at the beginning of January 1, 1970, UTC) to this instant. Equivalent to dividing `epochNanoseconds` by `1e6` and flooring it.
+- {{jsxref("Temporal/Instant/epochNanoseconds", "Temporal.Instant.prototype.epochNanoseconds")}} {{experimental_inline}}
+  - : Returns a {{jsxref("BigInt")}} representing the number of nanoseconds since the Unix epoch (midnight at the beginning of January 1, 1970, UTC) to this instant.
+- `Temporal.Instant.prototype[Symbol.toStringTag]`
+  - : The initial value of the [`[Symbol.toStringTag]`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol/toStringTag) property is the string `"Temporal.Instant"`. This property is used in {{jsxref("Object.prototype.toString()")}}.
+
+## Instance methods
+
+- {{jsxref("Temporal/Instant/add", "Temporal.Instant.prototype.add()")}} {{experimental_inline}}
+  - : Returns a new `Temporal.Instant` object representing this instant moved forward by a given duration (in a form convertible by {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}).
+- {{jsxref("Temporal/Instant/equals", "Temporal.Instant.prototype.equals()")}} {{experimental_inline}}
+  - : Returns `true` if this instant is equivalent in value to another instant (in a form convertible by {{jsxref("Temporal/Instant/from", "Temporal.Instant.from()")}}), and `false` otherwise. They are compared by their epoch nanoseconds. Equivalent to `Temporal.Instant.compare(this, other) === 0`.
+- {{jsxref("Temporal/Instant/round", "Temporal.Instant.prototype.round()")}} {{experimental_inline}}
+  - : Returns a new `Temporal.Instant` object representing this instant rounded to the given unit.
+- {{jsxref("Temporal/Instant/since", "Temporal.Instant.prototype.since()")}} {{experimental_inline}}
+  - : Returns a new {{jsxref("Temporal.Duration")}} object representing the duration from another instant (in a form convertible by {{jsxref("Temporal/Instant/from", "Temporal.Instant.from()")}}) to this instant. The duration is positive if the other instant is before this instant, and negative if after.
+- {{jsxref("Temporal/Instant/subtract", "Temporal.Instant.prototype.subtract()")}} {{experimental_inline}}
+  - : Returns a new `Temporal.Instant` object representing this instant moved backward by a given duration (in a form convertible by {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}).
+- {{jsxref("Temporal/Instant/toJSON", "Temporal.Instant.prototype.toJSON()")}} {{experimental_inline}}
+  - : Returns a string representing this instant in the same [RFC 9557 format](#rfc_9557_format) as calling {{jsxref("Temporal/Instant/toString", "toString()")}}. Intended to be implicitly called by {{jsxref("JSON.stringify()")}}.
+- {{jsxref("Temporal/Instant/toLocaleString", "Temporal.Instant.prototype.toLocaleString()")}} {{experimental_inline}}
+  - : Returns a string with a language-sensitive representation of this instant. In implementations with [`Intl.DateTimeFormat` API](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat) support, this method delegates to `Intl.DateTimeFormat`.
+- {{jsxref("Temporal/Instant/toString", "Temporal.Instant.prototype.toString()")}} {{experimental_inline}}
+  - : Returns a string representing this instant in the [RFC 9557 format](#rfc_9557_format) using the specified time zone.
+- {{jsxref("Temporal/Instant/toZonedDateTimeISO", "Temporal.Instant.prototype.toZonedDateTimeISO()")}} {{experimental_inline}}
+  - : Returns a new {{jsxref("Temporal.ZonedDateTime")}} object representing this instant in the specified time zone using the ISO 8601 calendar system.
+- {{jsxref("Temporal/Instant/until", "Temporal.Instant.prototype.until()")}} {{experimental_inline}}
+  - : Returns a new {{jsxref("Temporal.Duration")}} object representing the duration from this instant to another instant (in a form convertible by {{jsxref("Temporal/Instant/from", "Temporal.Instant.from()")}}). The duration is positive if the other instant is after this instant, and negative if before.
+- {{jsxref("Temporal/Instant/valueOf", "Temporal.Instant.prototype.valueOf()")}} {{experimental_inline}}
+  - : Throws a {{jsxref("TypeError")}}, which prevents `Temporal.Instant` instances from being [implicitly converted to primitives](/en-US/docs/Web/JavaScript/Data_structures#primitive_coercion) when used in arithmetic or comparison operations.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal")}}
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal.ZonedDateTime")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/instant/instant/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/instant/instant/index.md
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+---
+title: Temporal.Instant()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Instant/Instant
+page-type: javascript-constructor
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Instant.Instant
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.Instant()`** constructor creates {{jsxref("Temporal.Instant")}} objects.
+
+This constructor is exactly equivalent to calling {{jsxref("Temporal/Instant/fromEpochNanoseconds", "Temporal.Instant.fromEpochNanoseconds()")}}.
+
+## Syntax
+
+```js-nolint
+new Temporal.Instant(epochNanoseconds)
+```
+
+> **Note:** `Temporal.Instant()` can only be constructed with [`new`](/en-US/docs/Web/JavaScript/Reference/Operators/new). Attempting to call it without `new` throws a {{jsxref("TypeError")}}.
+
+### Parameters
+
+- `epochNanoseconds`
+  - : A [BigInt](/en-US/docs/Web/JavaScript/Reference/Global_Objects/BigInt) representing the number of nanoseconds since the Unix epoch.
+
+### Return value
+
+A new `Temporal.Instant` object representing the instant in time specified by `epochNanoseconds`.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown if `epochNanoseconds` is outside the range of a representable instant, which is ±10<sup>8</sup> days (±8.64e21 nanoseconds, or about ±273,972.6 years).
+
+## Examples
+
+### Using Temporal.Instant()
+
+```js
+const instant = new Temporal.Instant(0n);
+console.log(instant.toString()); // 1970-01-01T00:00:00Z
+const vostok1Liftoff = new Temporal.Instant(-275248380000000000n);
+console.log(vostok1Liftoff.toString()); // 1961-04-12T06:07:00Z
+const sts1Liftoff = new Temporal.Instant(355924804000000000n);
+console.log(sts1Liftoff.toString()); // 1981-04-12T12:00:04Z
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Instant")}}
+- {{jsxref("Temporal/Instant/epochNanoseconds", "Temporal.Instant.prototype.epochNanoseconds")}}
+- {{jsxref("Temporal/Instant/from", "Temporal.Instant.from()")}}
+- {{jsxref("Temporal/Instant/fromEpochMilliseconds", "Temporal.Instant.fromEpochMilliseconds()")}}
+- {{jsxref("Temporal/Instant/fromEpochNanoseconds", "Temporal.Instant.fromEpochNanoseconds()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/instant/round/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/instant/round/index.md
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+---
+title: Temporal.Instant.prototype.round()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Instant/round
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Instant.round
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`round()`** method of {{jsxref("Temporal.Instant")}} instances returns a new `Temporal.Instant` object representing this instant rounded to the given unit.
+
+## Syntax
+
+```js-nolint
+round(smallestUnit)
+round(options)
+```
+
+### Parameters
+
+- `smallestUnit`
+  - : A string representing the [`smallestUnit`](#smallestunit_2) option. This is a convenience overload, so `round(smallestUnit)` is equivalent to `round({ smallestUnit })`, where `smallestUnit` is a string.
+- `options`
+  - : An object containing some or all of the following properties (in the order they are retrieved and validated):
+    - `roundingIncrement` {{optional_inline}}
+      - : A number (truncated to an integer) representing the rounding increment in the given `smallestUnit`. Defaults to `1`. The increment and the `smallestUnit` must evenly divide 24 hours; for example, 45 seconds is a divisor of 86400 seconds, and 100 minutes is a divisor of 3600 minutes. This is slightly less strict than the `round()` method of the other classes, which all require the increment to be a divisor of the maximum value of the unit.
+    - `roundingMode` {{optional_inline}}
+      - : A string specifying how to round off the fractional part of `smallestUnit`. See [`Intl.NumberFormat()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/NumberFormat/NumberFormat#roundingmode). Defaults to `"halfExpand"`.
+    - `smallestUnit`
+      - : A string representing the smallest unit to include in the output. The value must be one of the following: `"hour"`, `"minute"`, `"second"`, `"millisecond"`, `"microsecond"`, `"nanosecond"`, or their plural forms. For units larger than `"nanosecond"`, fractional parts of the `smallestUnit` will be rounded according to the `roundingIncrement` and `roundingMode` settings.
+
+### Return value
+
+A new {{jsxref("Temporal.Instant")}} object representing this instant rounded to the given unit, where all units smaller than `smallestUnit` are zeroed out.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown if any of the options is invalid.
+
+## Examples
+
+### Rounding off small units
+
+```js
+const instant = Temporal.Instant.fromEpochMilliseconds(1000);
+const roundedInstant = instant.round("second");
+console.log(roundedInstant.epochMilliseconds); // 1000
+
+const instant2 = instant.round("minute");
+console.log(instant2.epochMilliseconds); // 0
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Instant")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/instant/since/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/instant/since/index.md
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@@ -0,0 +1,81 @@
+---
+title: Temporal.Instant.prototype.since()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Instant/since
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Instant.since
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`since()`** method of {{jsxref("Temporal.Instant")}} instances returns a new {{jsxref("Temporal.Duration")}} object representing the duration from another instant (in a form convertible by {{jsxref("Temporal/Instant/from", "Temporal.Instant.from()")}}) to this instant. The duration is positive if the other instant is before this instant, and negative if after.
+
+This method does `this - other`. To do `other - this`, use the {{jsxref("Temporal/Instant/until", "until()")}} method.
+
+## Syntax
+
+```js-nolint
+since(other)
+since(other, options)
+```
+
+### Parameters
+
+- `other`
+  - : A string or a {{jsxref("Temporal.Instant")}} instance representing an instant to subtract from this instant. It is converted to a `Temporal.Instant` object using the same algorithm as {{jsxref("Temporal/Instant/from", "Temporal.Instant.from()")}}.
+- `options` {{optional_inline}}
+  - : An object containing the options for {{jsxref("Temporal/Duration/round", "Temporal.Duration.prototype.round()")}}, which includes `largestUnit`, `roundingIncrement`, `roundingMode`, and `smallestUnit`. `largestUnit` and `smallestUnit` only accept the units: `"hour"`, `"minute"`, `"second"`, `"millisecond"`, `"microsecond"`, `"nanosecond"`, or their plural forms. For `largestUnit`, the default value `"auto"` means `"second"` or `smallestUnit`, whichever is greater. For `smallestUnit`, the default value is `"nanosecond"`.
+
+### Return value
+
+A new {{jsxref("Temporal.Duration")}} object representing the duration _since_ `other` to this instant. The duration is positive if `other` is before this instant, and negative if after.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown if any of the options is invalid.
+
+## Examples
+
+### Using since()
+
+```js
+const lastUpdated = Temporal.Instant.fromEpochMilliseconds(1735235418000);
+const now = Temporal.Now.instant();
+const duration = now.since(lastUpdated, { smallestUnit: "minute" });
+console.log(`Last updated ${duration.toLocaleString("en-US")} ago`);
+```
+
+### Balancing the resulting duration
+
+Because an instant does not carry calendar information, the resulting duration avoids [calendar durations](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#calendar_durations), which are ambiguous without a calendar and time reference. Therefore, the result is [unbalanced](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#duration_balancing) because `hours` may be greater than `24`. To balance the duration, [round](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration/round) the resulting duration again with the desired `largestUnit`, passing a `relativeTo` that carries the calendar information.
+
+```js
+const lastUpdated = Temporal.Instant.fromEpochMilliseconds(1735235418000);
+const now = Temporal.Now.instant();
+const duration = now.since(lastUpdated, { smallestUnit: "minute" });
+const roundedDuration = duration.round({
+  largestUnit: "year",
+  // Use the ISO calendar; you can convert to another calendar using
+  // withCalendar()
+  relativeTo: now.toZonedDateTimeISO("UTC"),
+});
+console.log(`Last updated ${roundedDuration.toLocaleString("en-US")} ago`);
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Instant")}}
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/Instant/add", "Temporal.Instant.prototype.add()")}}
+- {{jsxref("Temporal/Instant/subtract", "Temporal.Instant.prototype.subtract()")}}
+- {{jsxref("Temporal/Instant/until", "Temporal.Instant.prototype.until()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/instant/subtract/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/instant/subtract/index.md
new file mode 100644
index 000000000000000..333c967f85e28cf
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/instant/subtract/index.md
@@ -0,0 +1,69 @@
+---
+title: Temporal.Instant.prototype.subtract()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Instant/subtract
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Instant.subtract
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`subtract()`** method of {{jsxref("Temporal.Instant")}} instances returns a new `Temporal.Instant` object representing this instant moved backward by a given duration (in a form convertible by {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}).
+
+If you want to subtract two instants and get a duration, use {{jsxref("Temporal/Instant/since", "since()")}} or {{jsxref("Temporal/Instant/until", "until()")}} instead.
+
+## Syntax
+
+```js-nolint
+subtract(duration)
+```
+
+### Parameters
+
+- `duration`
+  - : A string, an object, or a {{jsxref("Temporal.Duration")}} instance representing a duration to subtract from this instant. It is converted to a `Temporal.Duration` object using the same algorithm as {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}.
+
+### Return value
+
+A new {{jsxref("Temporal.Instant")}} object representing subtracting `duration` from this instant. If `duration` is positive, then the returned instant is earlier than this instant; if `duration` is negative, then the returned instant is later than this instant.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown in one of the following cases:
+    - `duration` is a [calendar duration](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#calendar_durations) (it has a non-zero `years`, `months`, or `weeks`), or has a non-zero `days`, because calendar durations are ambiguous without a calendar and time reference.
+    - The difference of `this` and `duration` overflows the maximum or underflows the minimum representable instant, which is ±10<sup>8</sup> days (about ±273,972.6 years).
+
+## Description
+
+Subtracting a duration is equivalent to [adding](Web/JavaScript/Reference/Global_Objects/Temporal/Instant/add) its [negation](Web/JavaScript/Reference/Global_Objects/Temporal/Duration/negated), so all the same considerations apply.
+
+## Examples
+
+### Subtracting a Temporal.Duration
+
+```js
+const instant = Temporal.Instant.fromEpochMilliseconds(1000);
+const duration = Temporal.Duration.from("PT1S"); // One-second duration
+const newInstant = instant.subtract(duration);
+console.log(newInstant.epochMilliseconds); // 0
+```
+
+For more examples, see {{jsxref("Temporal/Instant/add", "add()")}}.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Instant")}}
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/Instant/add", "Temporal.Instant.prototype.add()")}}
+- {{jsxref("Temporal/Instant/since", "Temporal.Instant.prototype.since()")}}
+- {{jsxref("Temporal/Instant/until", "Temporal.Instant.prototype.until()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/instant/tojson/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/instant/tojson/index.md
new file mode 100644
index 000000000000000..40bde71bb5ea62a
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/instant/tojson/index.md
@@ -0,0 +1,70 @@
+---
+title: Temporal.Instant.prototype.toJSON()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Instant/toJSON
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Instant.toJSON
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toJSON()`** method of {{jsxref("Temporal.Instant")}} instances returns a string representing this instant in the same [RFC 9557 format](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Instant#rfc_9557_format) as calling {{jsxref("Temporal/Instant/toString", "toString()")}}. It is intended to be implicitly called by {{jsxref("JSON.stringify()")}}.
+
+## Syntax
+
+```js-nolint
+toJSON()
+```
+
+### Parameters
+
+None.
+
+### Return value
+
+A string representing the given instant in the [RFC 9557 format](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Instant#rfc_9557_format), with as much subsecond precision as necessary to represent the duration accurately, and with the UTC time zone designator `Z`.
+
+## Description
+
+The `toJSON()` method is automatically called by {{jsxref("JSON.stringify()")}} when a `Temporal.Instant` object is stringified. This method is generally intended to, by default, usefully serialize `Temporal.Instant` objects during [JSON](/en-US/docs/Glossary/JSON) serialization, which can then be deserialized using the {{jsxref("Temporal/Instant/from", "Temporal.Instant.from()")}} function as the reviver of {{jsxref("JSON.parse()")}}.
+
+## Examples
+
+### Using toJSON()
+
+```js
+const instant = Temporal.Instant.fromEpochMilliseconds(1627821296000);
+const instantStr = instant.toJSON(); // '2021-08-01T12:34:56Z'
+const i2 = Temporal.Instant.from(instantStr);
+```
+
+### JSON serialization and parsing
+
+This example shows how `Temporal.Instant` can be serialized as JSON without extra effort, and how to parse it back.
+
+```js
+const instant = Temporal.Instant.fromEpochMilliseconds(1627821296000);
+const jsonStr = JSON.stringify({ time: instant }); // '{"time":"2021-08-01T12:34:56Z"}'
+const obj = JSON.parse(jsonStr, (key, value) => {
+  if (key === "time") {
+    return Temporal.Instant.from(value);
+  }
+  return value;
+});
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Instant")}}
+- {{jsxref("Temporal/Instant/from", "Temporal.Instant.from()")}}
+- {{jsxref("Temporal/Instant/toString", "Temporal.Instant.prototype.toString()")}}
+- {{jsxref("Temporal/Instant/toLocaleString", "Temporal.Instant.prototype.toLocaleString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/instant/tolocalestring/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/instant/tolocalestring/index.md
new file mode 100644
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--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/instant/tolocalestring/index.md
@@ -0,0 +1,71 @@
+---
+title: Temporal.Instant.prototype.toLocaleString()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Instant/toLocaleString
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Instant.toLocaleString
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toLocaleString()`** method of {{jsxref("Temporal.Instant")}} instances returns a string with a language-sensitive representation of this instant. In implementations with [`Intl.DateTimeFormat` API](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat) support, this method delegates to `Intl.DateTimeFormat`.
+
+Every time `toLocaleString` is called, it has to perform a search in a big database of localization strings, which is potentially inefficient. When the method is called many times with the same arguments, it is better to create a {{jsxref("Intl.DateTimeFormat")}} object and use its {{jsxref("Intl/DateTimeFormat/format", "format()")}} method, because a `DateTimeFormat` object remembers the arguments passed to it and may decide to cache a slice of the database, so future `format` calls can search for localization strings within a more constrained context.
+
+## Syntax
+
+```js-nolint
+toLocaleString()
+toLocaleString(locales)
+toLocaleString(locales, options)
+```
+
+### Parameters
+
+The `locales` and `options` parameters customize the behavior of the function and let applications specify the language whose formatting conventions should be used.
+
+In implementations that support the [`Intl.DateTimeFormat` API](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat), these parameters correspond exactly to the [`Intl.DateTimeFormat()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat/DateTimeFormat) constructor's parameters. Implementations without `Intl.DateTimeFormat` support return the exact same string as {{jsxref("Temporal/Instant/toString", "toString()")}}, ignoring both parameters.
+
+- `locales` {{optional_inline}}
+  - : A string with a BCP 47 language tag, or an array of such strings. Corresponds to the [`locales`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat/DateTimeFormat#locales) parameter of the `Intl.DateTimeFormat()` constructor.
+- `options` {{optional_inline}}
+  - : An object adjusting the output format. Corresponds to the [`options`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat/DateTimeFormat#options) parameter of the `Intl.DateTimeFormat()` constructor.
+
+See the [`Intl.DateTimeFormat()` constructor](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat/DateTimeFormat) for details on these parameters and how to use them.
+
+### Return value
+
+A string representing the given instant according to language-specific conventions.
+
+In implementations with `Intl.DateTimeFormat`, this is equivalent to `new Intl.DateTimeFormat(locales, options).format(instant)`.
+
+> [!NOTE]
+> Most of the time, the formatting returned by `toLocaleString()` is consistent. However, the output may vary between implementations, even within the same locale — output variations are by design and allowed by the specification. It may also not be what you expect. For example, the string may use non-breaking spaces or be surrounded by bidirectional control characters. You should not compare the results of `toLocaleString()` to hardcoded constants.
+
+## Examples
+
+### Using toLocaleString()
+
+Basic use of this method without specifying a `locale` returns a formatted string in the default locale and with default options.
+
+```js
+const instant = Temporal.Instant.from("2021-08-01T12:34:56Z");
+
+console.log(instant.toLocaleString()); // 8/1/2021, 12:34:56 AM (assuming en-US locale and device in UTC time zone)
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Instant")}}
+- {{jsxref("Intl.DateTimeFormat")}}
+- {{jsxref("Temporal/Instant/toJSON", "Temporal.Instant.prototype.toJSON()")}}
+- {{jsxref("Temporal/Instant/toString", "Temporal.Instant.prototype.toString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/instant/tostring/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/instant/tostring/index.md
new file mode 100644
index 000000000000000..6b99ac1a7ef606d
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/instant/tostring/index.md
@@ -0,0 +1,84 @@
+---
+title: Temporal.Instant.prototype.toString()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Instant/toString
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Instant.toString
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toString()`** method of {{jsxref("Temporal.Instant")}} instances returns a string representing this instant in the [RFC 9557 format](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Instant#rfc_9557_format) using the specified time zone.
+
+## Syntax
+
+```js-nolint
+toString()
+toString(options)
+```
+
+### Parameters
+
+- `options` {{optional_inline}}
+  - : An object containing some or all of the following properties (in the order they are retrieved and validated):
+    - `fractionalSecondDigits` {{optional_inline}}
+      - : Either an integer from 0 to 9, or the string `"auto"`. The default is `"auto"`. If `"auto"`, then trailing zeros are removed from the fractional seconds. Otherwise, the fractional part of the second component contains this many digits, padded with zeros or rounded as necessary.
+    - `roundingMode` {{optional_inline}}
+      - : A string specifying how to round off fractional second digits beyond `fractionalSecondDigits`. See [`Intl.NumberFormat()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/NumberFormat/NumberFormat#roundingmode). Defaults to `"trunc"`.
+    - `smallestUnit` {{optional_inline}}
+      - : A string specifying the smallest unit to include in the output. Possible values are `"minute"`, `"second"`, `"millisecond"`, `"microsecond"`, and `"nanosecond"`, or their plural forms, which (except `"minute"`) are equivalent to `fractionalSecondDigits` values of `0`, `3`, `6`, `9`, respectively. If specified, then `fractionalSecondDigits` is ignored.
+    - `timeZone` {{optional_inline}}
+      - : Either a string or a {{jsxref("Temporal.ZonedDateTime")}} instance representing the time zone to use. If a `Temporal.ZonedDateTime` instance, its time zone is used. If a string, it can be a named time zone identifier, an offset time zone identifier, or a date-time string containing a time zone identifier or an offset (see [time zones and offsets](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#time_zones_and_offsets) for more information). Defaults to `"UTC"`.
+
+### Return value
+
+A string in the [RFC 9557 format](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Instant#rfc_9557_format) representing this instant using the specified time zone. No annotations, such as time zone names, are included.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown if any of the options is invalid.
+
+## Examples
+
+### Using toString()
+
+```js
+const instant = Temporal.Instant.fromEpochMilliseconds(1627814412345);
+console.log(instant.toString()); // '2021-08-01T10:40:12.345Z'
+
+// Stringification implicitly calls toString()
+console.log(`${instant}`); // '2021-08-01T10:40:12.345Z'
+```
+
+### Using options
+
+```js
+const instant = Temporal.Instant.fromEpochMilliseconds(1627814412345);
+console.log(instant.toString({ fractionalSecondDigits: 1 })); // '2021-08-01T10:40:12.3Z'
+console.log(instant.toString({ smallestUnit: "minute" })); // '2021-08-01T10:40Z'
+console.log(instant.toString({ timeZone: "America/New_York" })); // '2021-08-01T06:40:12.345-04:00'
+
+// The time zone name automatically resolves to the correct offset
+// based on the instant; for example, America/New_York is UTC-4 in summer,
+// but UTC-5 in winter.
+const instant2 = Temporal.Instant.fromEpochMilliseconds(1577836800000);
+console.log(instant2.toString({ timeZone: "UTC" })); // '2029-12-31T23:00:00Z'
+console.log(instant2.toString({ timeZone: "America/New_York" })); // '2019-12-31T19:00:00-05:00'
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Instant")}}
+- {{jsxref("Temporal/Instant/from", "Temporal.Instant.from()")}}
+- {{jsxref("Temporal/Instant/toJSON", "Temporal.Instant.prototype.toJSON()")}}
+- {{jsxref("Temporal/Instant/toLocaleString", "Temporal.Instant.prototype.toLocaleString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/instant/tozoneddatetimeiso/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/instant/tozoneddatetimeiso/index.md
new file mode 100644
index 000000000000000..6d218155ff53f62
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/instant/tozoneddatetimeiso/index.md
@@ -0,0 +1,61 @@
+---
+title: Temporal.Instant.prototype.toZonedDateTimeISO()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Instant/toZonedDateTimeISO
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Instant.toZonedDateTimeISO
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toZonedDateTimeISO()`** method of {{jsxref("Temporal.Instant")}} instances returns a new {{jsxref("Temporal.ZonedDateTime")}} object representing this instant in the specified time zone using the ISO 8601 calendar system.
+
+## Syntax
+
+```js-nolint
+toZonedDateTimeISO(timeZone)
+```
+
+### Parameters
+
+- `timeZone`
+  - : Either a string or a {{jsxref("Temporal.ZonedDateTime")}} instance representing the time zone to use. If a `Temporal.ZonedDateTime` instance, its time zone is used. If a string, it can be a named time zone identifier, an offset time zone identifier, or a date-time string containing a time zone identifier or an offset (see [time zones and offsets](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#time_zones_and_offsets) for more information).
+
+### Return value
+
+A new {{jsxref("Temporal.ZonedDateTime")}} object representing this instant in the specified time zone using the ISO 8601 calendar system.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown if the time zone name is invalid.
+- {{jsxref("TypeError")}}
+  - : Thrown if `timeZone` is not a string or a `Temporal.ZonedDateTime` instance.
+
+## Examples
+
+### Using toZonedDateTimeISO()
+
+```js
+const instant = Temporal.Instant.from("2021-08-01T12:34:56.123456789Z");
+const zonedDateTime = instant.toZonedDateTimeISO("America/New_York");
+console.log(zonedDateTime.toString()); // 2021-08-01T08:34:56.123456789-04:00[America/New_York]
+
+const localDateTime = instant.toZonedDateTimeISO(Temporal.Now.timeZoneId());
+console.log(localDateTime.toString()); // This instant in your timezone
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Instant")}}
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/toInstant", "Temporal.ZonedDateTime.prototype.toInstant()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/instant/until/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/instant/until/index.md
new file mode 100644
index 000000000000000..8031d919e7db82b
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/instant/until/index.md
@@ -0,0 +1,66 @@
+---
+title: Temporal.Instant.prototype.until()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Instant/until
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Instant.until
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`until()`** method of {{jsxref("Temporal.Instant")}} instances returns a new {{jsxref("Temporal.Duration")}} object representing the duration from this instant to another instant (in a form convertible by {{jsxref("Temporal/Instant/from", "Temporal.Instant.from()")}}). The duration is positive if the other instant is after this instant, and negative if before.
+
+This method does `other - this`. To do `this - other`, use the {{jsxref("Temporal/Instant/since", "since()")}} method.
+
+## Syntax
+
+```js-nolint
+until(other)
+until(other, options)
+```
+
+### Parameters
+
+- `other`
+  - : A string or a {{jsxref("Temporal.Instant")}} instance representing an instant to subtract this instant from. It is converted to a `Temporal.Instant` object using the same algorithm as {{jsxref("Temporal/Instant/from", "Temporal.Instant.from()")}}.
+- `options` {{optional_inline}}
+  - : The same options as [`since()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Instant/since#options).
+
+### Return value
+
+A new {{jsxref("Temporal.Duration")}} object representing the duration from this instant _until_ `other`. The duration is positive if `other` is after this instant, and negative if before.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown if any of the options is invalid.
+
+## Examples
+
+### Using until()
+
+```js
+const launch = Temporal.Instant.fromEpochMilliseconds(2051222400000);
+const now = Temporal.Now.instant();
+const duration = now.until(launch, { smallestUnit: "minute" });
+console.log(`It will be ${duration.toLocaleString("en-US")} until the launch`);
+```
+
+For more examples, see [`since()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Instant/since).
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Instant")}}
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/Instant/add", "Temporal.Instant.prototype.add()")}}
+- {{jsxref("Temporal/Instant/subtract", "Temporal.Instant.prototype.subtract()")}}
+- {{jsxref("Temporal/Instant/since", "Temporal.Instant.prototype.since()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/instant/valueof/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/instant/valueof/index.md
new file mode 100644
index 000000000000000..515e01f96770ad4
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/instant/valueof/index.md
@@ -0,0 +1,67 @@
+---
+title: Temporal.Instant.prototype.valueOf()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Instant/valueOf
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Instant.valueOf
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`valueOf()`** method of {{jsxref("Temporal.Instant")}} instances throws a {{jsxref("TypeError")}}, which prevents `Temporal.Instant` instances from being [implicitly converted to primitives](/en-US/docs/Web/JavaScript/Data_structures#primitive_coercion) when used in arithmetic or comparison operations.
+
+## Syntax
+
+```js-nolint
+valueOf()
+```
+
+### Parameters
+
+None.
+
+### Return value
+
+None.
+
+### Exceptions
+
+- {{jsxref("TypeError")}}
+  - : Always thrown.
+
+## Description
+
+Because both [primitive conversion](/en-US/docs/Web/JavaScript/Data_structures#primitive_coercion) and [number conversion](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number#number_coercion) call `valueOf()` before `toString()`, if `valueOf()` is absent, then an expression like `instant1 > instant2` would implicitly compare them as strings, which may have unexpected results. By throwing a `TypeError`, `Temporal.Instant` instances prevent such implicit conversions. You need to explicitly convert them to numbers using {{jsxref("Temporal/Instant/epochNanoseconds", "Temporal.Instant.prototype.epochNanoseconds")}}, or use the {{jsxref("Temporal/Instant/compare", "Temporal.Instant.compare()")}} static method to compare them.
+
+## Examples
+
+### Arithmetic and comparison operations on Temporal.Instant
+
+All arithmetic and comparison operations on `Temporal.Instant` instances should use the dedicated methods or convert them to primitives explicitly.
+
+```js
+const instant1 = Temporal.Instant.fromEpochMilliseconds(0);
+const instant2 = Temporal.Instant.fromEpochMilliseconds(1000);
+instant1 > instant2; // TypeError: can't convert Instant to primitive type
+instant1.epochNanoseconds > instant2.epochNanoseconds; // false
+Temporal.Instant.compare(instant1, instant2); // -1
+
+instant2 - instant1; // TypeError: can't convert Instant to primitive type
+instant2.since(instant1).toString(); // "PT1S"
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Instant")}}
+- {{jsxref("Temporal/Instant/toString", "Temporal.Instant.prototype.toString()")}}
+- {{jsxref("Temporal/Instant/toJSON", "Temporal.Instant.prototype.toJSON()")}}
+- {{jsxref("Temporal/Instant/toLocaleString", "Temporal.Instant.prototype.toLocaleString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/now/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/now/index.md
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--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/now/index.md
@@ -0,0 +1,83 @@
+---
+title: Temporal.Now
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Now
+page-type: javascript-namespace
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Now
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.Now`** object provides methods for getting the current time in various formats.
+
+## Description
+
+Unlike most global objects, `Temporal.Now` is not a constructor. You cannot use it with the [`new` operator](/en-US/docs/Web/JavaScript/Reference/Operators/new) or invoke the `Temporal.Now` object as a function. All properties and methods of `Temporal.Now` are static (just like the {{jsxref("Math")}} object).
+
+Most fundamentally, the system time is returned by the operating system as a time since the Unix epoch (usually millisecond-level precision, but might be nanosecond-level too). {{jsxref("Temporal/Now/instant", "Temporal.Now.instant()")}} returns this time as a {{jsxref("Temporal.Instant")}} object.
+
+An instant can be interpreted in a time zone (which is the system time zone {{jsxref("Temporal/Now/timeZoneId", "Temporal.Now.timeZoneId()")}} by default) in the same fashion as {{jsxref("Temporal/Instant/toZonedDateTimeISO", "Temporal.Instant.prototype.toZonedDateTimeISO()")}}. To get a {{jsxref("Temporal.ZonedDateTime")}} object, you can use {{jsxref("Temporal/Now/zonedDateTimeISO", "Temporal.Now.zonedDateTimeISO()")}}. You can also get different parts of the date and time, using {{jsxref("Temporal/Now/plainDateISO", "Temporal.Now.plainDateISO()")}}, {{jsxref("Temporal/Now/plainTimeISO", "Temporal.Now.plainTimeISO()")}}, and {{jsxref("Temporal/Now/plainDateTimeISO", "Temporal.Now.plainDateTimeISO()")}}.
+
+For example, if the computer is set to the time zone "America/New_York", `Temporal.Now.zonedDateTimeISO()` returns a zoned date-time like: `2021-08-01T10:40:12.345-04:00[America/New_York]`. In this case, `Temporal.Now.plainTimeISO()` would return the time part of this zoned date-time: `10:40:12.345`. However, if you call `Temporal.Now.plainTimeISO("UTC")`, it returns the time part of the zoned date-time in the UTC time zone: `14:40:12.345`. This is especially useful for cross-system communication where the other end may be expecting the time in a different time zone.
+
+### Reduced time precision
+
+To offer protection against timing attacks and [fingerprinting](/en-US/docs/Glossary/Fingerprinting), the precision of the `Temporal.Now` functions might get rounded depending on browser settings. In Firefox, the `privacy.reduceTimerPrecision` preference is enabled by default and defaults to 2ms. You can also enable `privacy.resistFingerprinting`, in which case the precision will be 100ms or the value of `privacy.resistFingerprinting.reduceTimerPrecision.microseconds`, whichever is larger.
+
+For example, with reduced time precision, the result of `Temporal.Now.instant().epochMilliseconds` will always be a multiple of 2, or a multiple of 100 (or `privacy.resistFingerprinting.reduceTimerPrecision.microseconds`) with `privacy.resistFingerprinting` enabled.
+
+```js
+// reduced time precision (2ms) in Firefox 60
+Temporal.Now.instant().epochMilliseconds;
+// Might be:
+// 1519211809934
+// 1519211810362
+// 1519211811670
+// …
+
+// reduced time precision with `privacy.resistFingerprinting` enabled
+Temporal.Now.instant().epochMilliseconds;
+// Might be:
+// 1519129853500
+// 1519129858900
+// 1519129864400
+// …
+```
+
+## Static properties
+
+- `Temporal.Now[Symbol.toStringTag]`
+  - : The initial value of the [`[Symbol.toStringTag]`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol/toStringTag) property is the string `"Temporal.Now"`. This property is used in {{jsxref("Object.prototype.toString()")}}.
+
+## Static methods
+
+- {{jsxref("Temporal/Now/instant", "Temporal.Now.instant()")}} {{experimental_inline}}
+  - : Returns the current time as a {{jsxref("Temporal.Instant")}} object.
+- {{jsxref("Temporal/Now/plainDateISO", "Temporal.Now.plainDateISO()")}} {{experimental_inline}}
+  - : Returns the current date as a {{jsxref("Temporal.PlainDate")}} object, in the ISO 8601 calendar and the specified time zone.
+- {{jsxref("Temporal/Now/plainDateTimeISO", "Temporal.Now.plainDateTimeISO()")}} {{experimental_inline}}
+  - : Returns the current date and time as a {{jsxref("Temporal.PlainDateTime")}} object, in the ISO 8601 calendar and the specified time zone.
+- {{jsxref("Temporal/Now/plainTimeISO", "Temporal.Now.plainTimeISO()")}} {{experimental_inline}}
+  - : Returns the current time as a {{jsxref("Temporal.PlainTime")}} object, in the specified time zone.
+- {{jsxref("Temporal/Now/timeZoneId", "Temporal.Now.timeZoneId()")}} {{experimental_inline}}
+  - : Returns a [time zone identifier](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#time_zones_and_offsets) representing the system's current time zone.
+- {{jsxref("Temporal/Now/zonedDateTimeISO", "Temporal.Now.zonedDateTimeISO()")}} {{experimental_inline}}
+  - : Returns the current date and time as a {{jsxref("Temporal.ZonedDateTime")}} object, in the ISO 8601 calendar and the specified time zone.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal")}}
+- {{jsxref("Temporal.Instant")}}
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal.PlainTime")}}
+- {{jsxref("Temporal.ZonedDateTime")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/now/instant/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/now/instant/index.md
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+---
+title: Temporal.Now.instant()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Now/instant
+page-type: javascript-static-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Now.instant
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.Now.instant()`** static method returns the current time as a {{jsxref("Temporal.Instant")}} object.
+
+## Syntax
+
+```js-nolint
+Temporal.Now.instant()
+```
+
+### Parameters
+
+None.
+
+### Return value
+
+A {{jsxref("Temporal.Instant")}} object representing the current time, with potentially [reduced precision](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Now#reduced_time_precision).
+
+## Examples
+
+### Measuring time elapsed
+
+The following example measures two instants in time and calculates the [duration](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration) between them, and gets the total duration in milliseconds:
+
+```js
+const start = Temporal.Now.instant();
+// Do something that takes time
+const end = Temporal.Now.instant();
+const duration = end.since(start);
+console.log(duration.total("milliseconds"));
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Now")}}
+- {{jsxref("Temporal.Instant")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/now/plaindateiso/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/now/plaindateiso/index.md
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@@ -0,0 +1,60 @@
+---
+title: Temporal.Now.plainDateISO()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Now/plainDateISO
+page-type: javascript-static-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Now.plainDateISO
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.Now.plainDateISO()`** static method returns the current date as a {{jsxref("Temporal.PlainDate")}} object, in the ISO 8601 calendar and the specified time zone.
+
+## Syntax
+
+```js-nolint
+Temporal.Now.plainDateISO()
+Temporal.Now.plainDateISO(timeZone)
+```
+
+### Parameters
+
+- `timeZone` {{optional_inline}}
+  - : Either a string or a {{jsxref("Temporal.ZonedDateTime")}} instance representing the time zone to interpret the system time in. If a `Temporal.ZonedDateTime` instance, its time zone is used. If a string, it can be a named time zone identifier, an offset time zone identifier, or a date-time string containing a time zone identifier or an offset (see [time zones and offsets](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#time_zones_and_offsets) for more information).
+
+### Return value
+
+The current date in the specified time zone, as a {{jsxref("Temporal.PlainDate")}} object using the ISO 8601 calendar.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown if the time zone is invalid.
+
+## Examples
+
+### Using Temporal.Now.plainDateISO()
+
+```js
+// The current date in the system's time zone
+const date = Temporal.Now.plainDateISO();
+console.log(date); // e.g.: 2021-10-01
+
+// The current date in the "America/New_York" time zone
+const dateInNewYork = Temporal.Now.plainDateISO("America/New_York");
+console.log(dateInNewYork); // e.g.: 2021-09-30
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Now")}}
+- {{jsxref("Temporal.PlainDate")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/now/plaindatetimeiso/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/now/plaindatetimeiso/index.md
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+---
+title: Temporal.Now.plainDateTimeISO()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Now/plainDateTimeISO
+page-type: javascript-static-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Now.plainDateTimeISO
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.Now.plainDateTimeISO()`** static method returns the current date and time as a {{jsxref("Temporal.PlainDateTime")}} object, in the ISO 8601 calendar and the specified time zone.
+
+## Syntax
+
+```js-nolint
+Temporal.Now.plainDateTimeISO()
+Temporal.Now.plainDateTimeISO(timeZone)
+```
+
+### Parameters
+
+- `timeZone` {{optional_inline}}
+  - : Either a string or a {{jsxref("Temporal.ZonedDateTime")}} instance representing the time zone to interpret the system time in. If a `Temporal.ZonedDateTime` instance, its time zone is used. If a string, it can be a named time zone identifier, an offset time zone identifier, or a date-time string containing a time zone identifier or an offset (see [time zones and offsets](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#time_zones_and_offsets) for more information).
+
+### Return value
+
+The current date and time in the specified time zone, as a {{jsxref("Temporal.PlainDateTime")}} object using the ISO 8601 calendar. Has the same precision as {{jsxref("Temporal/Now/instant", "Temporal.Now.instant()")}}.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown if the time zone is invalid.
+
+## Examples
+
+### Using Temporal.Now.plainDateTimeISO()
+
+```js
+// The current date and time in the system's time zone
+const dateTime = Temporal.Now.plainDateTimeISO();
+console.log(dateTime); // e.g.: 2021-10-01T06:12:34.567890123
+
+// The current date and time in the "America/New_York" time zone
+const dateTimeInNewYork = Temporal.Now.plainDateTimeISO("America/New_York");
+console.log(dateTimeInNewYork); // e.g.: 2021-09-30T23:12:34.567890123
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Now")}}
+- {{jsxref("Temporal.PlainDateTime")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/now/plaintimeiso/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/now/plaintimeiso/index.md
new file mode 100644
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@@ -0,0 +1,62 @@
+---
+title: Temporal.Now.plainTimeISO()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Now/plainTimeISO
+page-type: javascript-static-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Now.plainTimeISO
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.Now.plainTimeISO()`** static method returns the current time as a {{jsxref("Temporal.PlainTime")}} object, in the specified time zone.
+
+Note that although the method contains "ISO" in its name, {{jsxref("Temporal.PlainTime")}} objects do not have associated calendars, as the time format is not calendar-dependent.
+
+## Syntax
+
+```js-nolint
+Temporal.Now.plainTimeISO()
+Temporal.Now.plainTimeISO(timeZone)
+```
+
+### Parameters
+
+- `timeZone` {{optional_inline}}
+  - : Either a string or a {{jsxref("Temporal.ZonedDateTime")}} instance representing the time zone to interpret the system time in. If a `Temporal.ZonedDateTime` instance, its time zone is used. If a string, it can be a named time zone identifier, an offset time zone identifier, or a date-time string containing a time zone identifier or an offset (see [time zones and offsets](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#time_zones_and_offsets) for more information).
+
+### Return value
+
+The current time in the specified time zone, as a {{jsxref("Temporal.PlainTime")}} object. Has the same precision as {{jsxref("Temporal/Now/instant", "Temporal.Now.instant()")}}.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown if the time zone is invalid.
+
+## Examples
+
+### Using Temporal.Now.plainTimeISO()
+
+```js
+// The current time in the system's time zone
+const time = Temporal.Now.plainTimeISO();
+console.log(time); // e.g.: 06:12:34.567890123
+
+// The current time in the "America/New_York" time zone
+const timeInNewYork = Temporal.Now.plainTimeISO("America/New_York");
+console.log(timeInNewYork); // e.g.: 23:12:34.567890123
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Now")}}
+- {{jsxref("Temporal.PlainTime")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/now/timezoneid/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/now/timezoneid/index.md
new file mode 100644
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--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/now/timezoneid/index.md
@@ -0,0 +1,48 @@
+---
+title: Temporal.Now.timeZoneId()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Now/timeZoneId
+page-type: javascript-static-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Now.timeZoneId
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.Now.timeZoneId()`** static method returns a [time zone identifier](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#time_zones_and_offsets) representing the system's current time zone. Most systems will return a primary time zone identifier such as `"America/New_York"`, though offset time zone identifier such as `"-04:00"` is possible too. The time zone identifier returned is the default time zone used by the other `Temporal.Now` methods.
+
+## Syntax
+
+```js-nolint
+Temporal.Now.timeZoneId()
+```
+
+### Parameters
+
+None.
+
+### Return value
+
+A valid [time zone identifier](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#time_zones_and_offsets) representing the system's current time zone. The returned time zone identifier is never a non-primary time zone identifier (alias). For example, it would always return `"Asia/Kolkata"` (new name) instead of `"Asia/Calcutta"` (old name). For more information, see [time zones and offsets](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#time_zones_and_offsets).
+
+If the implementation does not support time zones, the method always returns `"UTC"`.
+
+## Examples
+
+### Getting the system's current time zone
+
+```js
+console.log(Temporal.Now.timeZoneId()); // e.g.: "America/New_York"
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Now")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/now/zoneddatetimeiso/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/now/zoneddatetimeiso/index.md
new file mode 100644
index 000000000000000..08468316e74b52d
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/now/zoneddatetimeiso/index.md
@@ -0,0 +1,60 @@
+---
+title: Temporal.Now.zonedDateTimeISO()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/Now/zonedDateTimeISO
+page-type: javascript-static-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.Now.zonedDateTimeISO
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.Now.zonedDateTimeISO()`** static method returns the current date and time as a {{jsxref("Temporal.ZonedDateTime")}} object, in the ISO 8601 calendar and the specified time zone.
+
+## Syntax
+
+```js-nolint
+Temporal.Now.zonedDateTimeISO()
+Temporal.Now.zonedDateTimeISO(timeZone)
+```
+
+### Parameters
+
+- `timeZone` {{optional_inline}}
+  - : Either a string or a {{jsxref("Temporal.ZonedDateTime")}} instance representing the time zone to interpret the system time in. If a `Temporal.ZonedDateTime` instance, its time zone is used. If a string, it can be a named time zone identifier, an offset time zone identifier, or a date-time string containing a time zone identifier or an offset (see [time zones and offsets](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#time_zones_and_offsets) for more information).
+
+### Return value
+
+The current date and time in the specified time zone, as a {{jsxref("Temporal.ZonedDateTime")}} object using the ISO 8601 calendar. Has the same precision as {{jsxref("Temporal/Now/instant", "Temporal.Now.instant()")}}.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown if the time zone is invalid.
+
+## Examples
+
+### Using Temporal.Now.zonedDateTimeISO()
+
+```js
+// The current date and time in the system's time zone
+const dateTime = Temporal.Now.zonedDateTimeISO();
+console.log(dateTime); // e.g.: 2021-10-01T06:12:34.567890123+03:00
+
+// The current date and time in the "America/New_York" time zone
+const dateTimeInNewYork = Temporal.Now.zonedDateTimeISO("America/New_York");
+console.log(dateTimeInNewYork); // e.g.: 2021-09-30T23:12:34.567890123-04:00
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.Now")}}
+- {{jsxref("Temporal.ZonedDateTime")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/add/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/add/index.md
new file mode 100644
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--- /dev/null
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@@ -0,0 +1,148 @@
+---
+title: Temporal.PlainDate.prototype.add()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate/add
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDate.add
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`add()`** method of {{jsxref("Temporal.PlainDate")}} instances returns a new `Temporal.PlainDate` object representing this date moved forward by a given duration (in a form convertible by {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}).
+
+## Syntax
+
+```js-nolint
+add(duration)
+add(duration, options)
+```
+
+### Parameters
+
+- `duration`
+  - : A string, an object, or a {{jsxref("Temporal.Duration")}} instance representing a duration to add to this date. It is converted to a `Temporal.Duration` object using the same algorithm as {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}.
+- `options` {{optional_inline}}
+  - : An object containing the following property:
+    - `overflow` {{optional_inline}}
+      - : A string specifying the behavior when a date component is out of range. Possible values are:
+        - `"constrain"` (default)
+          - : The date component is [clamped](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate#invalid_date_clamping) to the valid range.
+        - `"reject"`
+          - : A {{jsxref("RangeError")}} is thrown if the date component is out of range.
+
+### Return value
+
+A new `Temporal.PlainDate` object representing the date specified by the original `PlainDate`, plus the duration.
+
+## Description
+
+The `duration` is handled in this way:
+
+- Move forward by the number of years, keeping the `monthCode` and `day` the same. If the `monthCode` is invalid in the resulting year (impossible for Gregorian and ISO 8601, but possible for calendars with leap months), we adjust based on the `overflow` option: for `constrain`, we pick another month according to the cultural conventions of that calendar's users. For example, because the leap month is usually thought of as a duplicate of another month, we may pick the month that it is a duplicate of.
+- Move forward by the number of months, adjusting the year if necessary, keeping the `day` the same. If the `day` is invalid in the resulting month (e.g., February 30), we adjust based on the `overflow` option: for `constrain`, we pick the closest valid day (e.g., February 28 or 29).
+- All commonly supported calendars use fixed-length weeks, so the number of weeks is just converted to the number of days. If the rule is more complex, we may take an approach similar to shifting months.
+- For all [non-calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#calendar_durations) units (days, hours, minutes, seconds, milliseconds, microseconds, nanoseconds), they are converted to the number of days. Fractional part of a day is ignored. Then, we move forward by that number of days, adjusting the month and year if necessary.
+
+Adding a duration is equivalent to [subtracting](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate/subtract) its [negation](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration/negated).
+
+## Examples
+
+### Adding a duration in ISO 8601 calendar
+
+```js
+const start = Temporal.PlainDate.from("2021-01-01");
+const end = start.add({ years: 1, months: 2, weeks: 3, days: 4 });
+console.log(end.toString()); // 2022-03-26
+
+const end2 = start.add({ years: -1, months: -2, weeks: -3, days: -4 });
+console.log(end2.toString()); // 2019-10-07
+
+const distance = Temporal.PlainDate.from("2020-01-01").until("2021-01-01"); // 366 days
+const end3 = start.add(distance);
+console.log(end3.toString()); // 2022-01-02
+```
+
+### Adding a duration in a non-ISO calendar
+
+```js
+const start = Temporal.PlainDate.from("2021-01-01[u-ca=chinese]");
+console.log(start.toLocaleString("en-US", { calendar: "chinese" })); // 11/18/2020
+const end = start.add({ months: 1 });
+console.log(end.toLocaleString("en-US", { calendar: "chinese" })); // 12/18/2020
+```
+
+### Adding a duration with overflow
+
+If we move a few months and the corresponding day is invalid in this month, then we adjust the day based on the `overflow` option.
+
+```js
+const start = Temporal.PlainDate.from("2021-01-31");
+const end = start.add({ months: 1 });
+console.log(end.toString()); // 2021-02-28
+
+// Any further day additions are based on the clamped month-day:
+const end2 = start.add({ months: 1, days: 31 });
+console.log(end2.toString()); // 2021-03-31
+
+// Compare with the same addition in a different order that results in no overflow:
+const end3 = start.add({ days: 31 }).add({ months: 1 });
+console.log(end3.toString()); // 2021-04-03
+```
+
+Overflow can also occur for the month, for calendars where different years have different numbers of months (usually due to leap months).
+
+```js
+const start = Temporal.PlainDate.from("2023-04-01[u-ca=chinese]");
+console.log(start.toLocaleString("en-US", { calendar: "chinese" })); // 2bis/11/2023; "bis" means leap month
+const end = start.add({ years: 1 });
+console.log(end.toLocaleString("en-US", { calendar: "chinese" })); // 3/11/2024
+
+// Compare:
+const start = Temporal.PlainDate.from("2023-04-30[u-ca=chinese]");
+console.log(start.toLocaleString("en-US", { calendar: "chinese" })); // 3/11/2023
+const end = start.add({ years: 1 });
+console.log(end.toLocaleString("en-US", { calendar: "chinese" })); // 3/11/2024; same day as above!
+```
+
+Note that the following is not an overflow because the month can just increment:
+
+```js
+const start = Temporal.PlainDate.from("2021-01-01");
+const end = start.add({ days: 100 });
+console.log(end.toString()); // 2021-04-11
+```
+
+You can also throw an error if the date component is out of range:
+
+```js
+const start = Temporal.PlainDate.from("2021-01-31");
+const end = start.add({ months: 1 }, { overflow: "reject" }); // RangeError: date value "day" not in 1..28: 31
+
+const start = Temporal.PlainDate.from("2023-04-01[u-ca=chinese]");
+const end = start.add({ years: 1 }, { overflow: "reject" }); // RangeError: invalid "monthCode" calendar field: M02L
+```
+
+### Adding time durations
+
+Fractional parts of a day are ignored.
+
+```js
+const start = Temporal.PlainDate.from("2021-01-01");
+const end = start.add({ hours: 25 }); // Same as adding 1 day
+console.log(end.toString()); // 2021-01-02
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/PlainDate/subtract", "Temporal.PlainDate.prototype.subtract()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/calendarid/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/calendarid/index.md
new file mode 100644
index 000000000000000..79a92b6b4cb5f4a
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/calendarid/index.md
@@ -0,0 +1,43 @@
+---
+title: Temporal.PlainDate.prototype.calendarId
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate/calendarId
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDate.calendarId
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`calendarId`** accessor property of {{jsxref("Temporal.PlainDate")}} instances returns a string representing the [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars) used to interpret the internal ISO 8601 date.
+
+For a list of commonly supported values, see {{jsxref("Intl/Locale/getCalendars", "Intl.Locale.prototype.getCalendars()")}}.
+
+The set accessor of `calendarId` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/PlainDate/withCalendar", "withCalendar()")}} method to create a new `Temporal.PlainDate` object with the desired new value.
+
+## Examples
+
+### Using calendarId
+
+```js
+const date = Temporal.PlainDate.from("2021-07-01");
+console.log(date.calendarId); // "iso8601"; default
+
+const date2 = Temporal.PlainDate.from("2021-07-01[u-ca=chinese]");
+console.log(date2.calendarId); // "chinese"
+
+const date3 = date2.withCalendar("hebrew");
+console.log(date3.calendarId); // "hebrew"
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDate")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/compare/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/compare/index.md
new file mode 100644
index 000000000000000..5914b41eaf382e0
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/compare/index.md
@@ -0,0 +1,99 @@
+---
+title: Temporal.PlainDate.compare()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate/compare
+page-type: javascript-static-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDate.compare
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.PlainDate.compare()`** static method returns a number (-1, 0, or 1) indicating whether the first date comes before, is the same as, or comes after the second date. Equivalent to comparing the year, month, and day fields of the underlying ISO 8601 dates.
+
+## Syntax
+
+```js-nolint
+Temporal.PlainDate.compare(date1, date2)
+```
+
+### Parameters
+
+- `date1`
+  - : A string, an object, or a {{jsxref("Temporal.PlainDate")}} instance representing the first date to compare. It is converted to a `Temporal.PlainDate` object using the same algorithm as {{jsxref("Temporal/PlainDate/from", "Temporal.PlainDate.from()")}}.
+- `date2`
+  - : The second date to compare, converted to a `Temporal.PlainDate` object using the same algorithm as `date1`.
+
+### Return value
+
+Returns `-1` if `date1` comes before `date2`, `0` if they are the same, and `1` if `date2` comes after. They are compared by their underlying date values, ignoring their calendars.
+
+## Examples
+
+### Using Temporal.PlainDate.compare()
+
+```js
+const date1 = Temporal.PlainDate.from("2021-08-01");
+const date2 = Temporal.PlainDate.from("2021-08-02");
+console.log(Temporal.PlainDate.compare(date1, date2)); // -1
+
+const date3 = Temporal.PlainDate.from("2021-07-31");
+console.log(Temporal.PlainDate.compare(date1, date3)); // 1
+```
+
+### Comparing dates in different calendars
+
+```js
+const date1 = Temporal.PlainDate.from({ year: 2021, month: 8, day: 1 });
+const date2 = Temporal.PlainDate.from({
+  year: 2021,
+  month: 8,
+  day: 1,
+  calendar: "islamic",
+});
+const date3 = Temporal.PlainDate.from({
+  year: 2021,
+  month: 8,
+  day: 1,
+  calendar: "hebrew",
+});
+console.log(date1.toString()); // "2021-08-01"
+console.log(date2.toString()); // "2582-12-18[u-ca=islamic]"
+console.log(date3.toString()); // "-001739-04-06[u-ca=hebrew]"
+console.log(Temporal.PlainDate.compare(date1, date2)); // -1
+console.log(Temporal.PlainDate.compare(date1, date3)); // 1
+```
+
+### Sorting an array of dates
+
+The purpose of this `compare()` function is to act as a comparator to be passed to {{jsxref("Array.prototype.sort()")}} and related functions.
+
+```js
+const dates = [
+  Temporal.PlainDate.from({ year: 2021, month: 8, day: 1 }),
+  Temporal.PlainDate.from({
+    year: 2021,
+    month: 8,
+    day: 1,
+    calendar: "islamic",
+  }),
+  Temporal.PlainDate.from({ year: 2021, month: 8, day: 1, calendar: "hebrew" }),
+];
+
+dates.sort(Temporal.PlainDate.compare);
+console.log(dates.map((d) => d.toString()));
+// [ "-001739-04-06[u-ca=hebrew]", "2021-08-01", "2582-12-18[u-ca=islamic]" ]
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal/PlainDate/equals", "Temporal.PlainDate.prototype.equals()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/day/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/day/index.md
new file mode 100644
index 000000000000000..f076007e9452e21
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/day/index.md
@@ -0,0 +1,90 @@
+---
+title: Temporal.PlainDate.prototype.day
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate/day
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDate.day
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`day`** accessor property of {{jsxref("Temporal.PlainDate")}} instances returns a positive integer representing the 1-based day index in the month of this date, which is the same day number you would see on a calendar. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+It generally starts at 1 and is continuous, but not always. If you want to loop through all the days in a month, first use {{jsxref("Temporal/PlainDate/with", "with()")}} with `{ day: 1 }` (which sets to the beginning of the month, even if the actual number is not `1`), then repeatedly use {{jsxref("Temporal/PlainDate/add", "add()")}} with `{ days: 1 }`, until the month changes.
+
+> [!NOTE]
+> Usually, the day index only changes when transitioning from one calendar system into another, such as [from the Julian to the Gregorian calendar](https://en.wikipedia.org/wiki/Adoption_of_the_Gregorian_calendar). In practice, all currently built-in calendars are [proleptic](https://en.wikipedia.org/wiki/Proleptic_Gregorian_calendar), meaning the calendar system is extended indefinitely into the past and future. Assuming `day` is non-continuous guards against future introductions of non-proleptic calendars.
+
+The set accessor of `day` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/PlainDate/with", "with()")}} method to create a new `Temporal.PlainDate` object with the desired new value.
+
+## Examples
+
+### Using day
+
+```js
+const date = Temporal.PlainDate.from("2021-07-01"); // ISO 8601 calendar
+console.log(date.day); // 1
+
+const date2 = Temporal.PlainDate.from("2021-07-01[u-ca=chinese]");
+console.log(date2.day); // 22; it is May 22 in the Chinese calendar
+```
+
+### Looping through all days in a month
+
+```js
+const month = Temporal.PlainDate.from("2021-07-14"); // An arbitrary date in the month
+for (
+  let day = month.with({ day: 1 });
+  day.month === month.month;
+  day = day.add({ days: 1 })
+) {
+  console.log(day.day);
+}
+```
+
+### Changing day
+
+```js
+const date = Temporal.PlainDate.from("2021-07-01");
+const newDate = date.with({ day: 15 });
+console.log(newDate.toString()); // 2021-07-15
+```
+
+You can also use {{jsxref("Temporal/PlainDate/add", "add()")}} or {{jsxref("Temporal/PlainDate/subtract", "subtract()")}} to move a certain number of days from the current date.
+
+```js
+const date = Temporal.PlainDate.from("2021-07-01");
+const newDate = date.add({ days: 14 });
+console.log(newDate.toString()); // 2021-07-15
+```
+
+By default, `with()` constrains the day to the range of valid values. So you can use `{ day: 1 }` to set the day to the first day of the month, even if the first day does not have the number `1`. Similarly, the following will set the day to the last day of the month:
+
+```js
+const date = Temporal.PlainDate.from("2021-07-01");
+const lastDay = date.with({ day: Number.MAX_VALUE }); // 2021-07-31
+```
+
+> [!NOTE]
+> Avoid using {{jsxref("Temporal/PlainDate/daysInMonth", "daysInMonth")}} to set the day to the last day of the month. The last day of the month is not always the same as the number of days in the month, in the rare case where a month may have a few days skipped.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal/PlainDate/with", "Temporal.PlainDate.prototype.with()")}}
+- {{jsxref("Temporal/PlainDate/add", "Temporal.PlainDate.prototype.add()")}}
+- {{jsxref("Temporal/PlainDate/subtract", "Temporal.PlainDate.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainDate/year", "Temporal.PlainDate.prototype.year")}}
+- {{jsxref("Temporal/PlainDate/month", "Temporal.PlainDate.prototype.month")}}
+- {{jsxref("Temporal/PlainDate/daysInMonth", "Temporal.PlainDate.prototype.daysInMonth")}}
+- {{jsxref("Temporal/PlainDate/dayOfWeek", "Temporal.PlainDate.prototype.dayOfWeek")}}
+- {{jsxref("Temporal/PlainDate/dayOfYear", "Temporal.PlainDate.prototype.dayOfYear")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/dayofweek/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/dayofweek/index.md
new file mode 100644
index 000000000000000..022c2a3b1b7670d
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/dayofweek/index.md
@@ -0,0 +1,101 @@
+---
+title: Temporal.PlainDate.prototype.dayOfWeek
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate/dayOfWeek
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDate.dayOfWeek
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`dayOfWeek`** accessor property of {{jsxref("Temporal.PlainDate")}} instances returns a positive integer representing the 1-based day index in the week of this date. Days in a week are numbered sequentially from `1` to {{jsxref("Temporal/PlainDate/daysInWeek", "daysInWeek")}}, with each number mapping to its name. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. 1 usually represents Monday in the calendar, even when locales using the calendar may consider a different day as the first day of the week (see {{jsxref("Intl/Locale/getWeekInfo", "Intl.Locale.prototype.getWeekInfo()")}}).
+
+All commonly supported calendars use 7-day weeks, and you could generally expect this property to return the same value for the same date across different calendars.
+
+The set accessor of `dayOfWeek` is `undefined`. You cannot change this property directly. To create a new `Temporal.PlainDate` object with the desired new `dayOfWeek` value, use the {{jsxref("Temporal/PlainDate/add", "add()")}} or {{jsxref("Temporal/PlainDate/subtract", "subtract()")}} method with the appropriate number of `days`.
+
+## Examples
+
+### Using dayOfWeek
+
+```js
+const date = Temporal.PlainDate.from("2021-07-01");
+console.log(date.dayOfWeek); // 4; Thursday
+
+const date2 = Temporal.PlainDate.from("2021-07-01[u-ca=chinese]");
+console.log(date2.dayOfWeek); // 4
+```
+
+### Changing dayOfWeek
+
+`PlainDate` does not support changing `dayOfWeek` directly. To change the day of the week, you need to first figure out the difference in days to your desired day of the week, then use `add` or `subtract` to adjust the date accordingly. For example, to change to the Friday of this week (whether before or after):
+
+```js
+function getDayInSameWeek(date, destDayOfWeek) {
+  return date.add({ days: destDayOfWeek - date.dayOfWeek });
+}
+
+console.log(
+  getDayInSameWeek(Temporal.PlainDate.from("2021-07-01"), 5).toString(),
+); // 2021-07-02
+console.log(
+  getDayInSameWeek(Temporal.PlainDate.from("2021-07-03"), 5).toString(),
+); // 2021-07-02
+```
+
+To change to the next Friday:
+
+```js
+function getNextDayInWeek(date, destDayOfWeek) {
+  const distance = destDayOfWeek - date.dayOfWeek;
+  return date.add({
+    days: distance < 0 ? date.daysInWeek + distance : distance,
+  });
+}
+
+console.log(
+  getNextDayInWeek(Temporal.PlainDate.from("2021-07-01"), 5).toString(),
+); // 2021-07-02
+console.log(
+  getNextDayInWeek(Temporal.PlainDate.from("2021-07-03"), 5).toString(),
+); // 2021-07-09
+```
+
+To change to the previous Friday:
+
+```js
+function getPreviousDayInWeek(date, destDayOfWeek) {
+  const distance = date.dayOfWeek - destDayOfWeek;
+  return date.subtract({
+    days: distance < 0 ? date.daysInWeek + distance : distance,
+  });
+}
+
+console.log(
+  getPreviousDayInWeek(Temporal.PlainDate.from("2021-07-01"), 5).toString(),
+); // 2021-06-25
+console.log(
+  getPreviousDayInWeek(Temporal.PlainDate.from("2021-07-03"), 5).toString(),
+); // 2021-07-02
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal/PlainDate/with", "Temporal.PlainDate.prototype.with()")}}
+- {{jsxref("Temporal/PlainDate/add", "Temporal.PlainDate.prototype.add()")}}
+- {{jsxref("Temporal/PlainDate/subtract", "Temporal.PlainDate.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainDate/day", "Temporal.PlainDate.prototype.day")}}
+- {{jsxref("Temporal/PlainDate/dayOfYear", "Temporal.PlainDate.prototype.dayOfYear")}}
+- {{jsxref("Temporal/PlainDate/daysInWeek", "Temporal.PlainDate.prototype.daysInWeek")}}
+- {{jsxref("Temporal/PlainDate/weekOfYear", "Temporal.PlainDate.prototype.weekOfYear")}}
+- {{jsxref("Temporal/PlainDate/yearOfWeek", "Temporal.PlainDate.prototype.yearOfWeek")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/dayofyear/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/dayofyear/index.md
new file mode 100644
index 000000000000000..1619bd0b2a0f94f
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/dayofyear/index.md
@@ -0,0 +1,75 @@
+---
+title: Temporal.PlainDate.prototype.dayOfYear
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate/dayOfYear
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDate.dayOfYear
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`dayOfYear`** accessor property of {{jsxref("Temporal.PlainDate")}} instances returns a positive integer representing the 1-based day index in the year of this date. The first day of this year is `1`, and the last day is the {{jsxref("Temporal/PlainDate/daysInYear", "daysInYear")}}. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+The set accessor of `dayOfYear` is `undefined`. You cannot change this property directly. To create a new `Temporal.PlainDate` object with the desired new `dayOfYear` value, use the {{jsxref("Temporal/PlainDate/add", "add()")}} or {{jsxref("Temporal/PlainDate/subtract", "subtract()")}} method with the appropriate number of `days`.
+
+## Examples
+
+### Using dayOfYear
+
+```js
+const date = Temporal.PlainDate.from("2021-07-01");
+console.log(date.dayOfYear); // 182
+
+const date2 = Temporal.PlainDate.from("2021-07-01[u-ca=chinese]");
+console.log(date2.dayOfYear); // 140
+
+const date3 = Temporal.PlainDate.from("2020-07-01");
+console.log(date3.dayOfYear); // 183; 2020 is a leap year
+```
+
+### Changing dayOfYear
+
+`PlainDate` does not support changing `dayOfYear` directly. To change the day of the year, you need to first figure out the difference in days to your desired day of the year, then use `add` or `subtract` to adjust the date accordingly. For example, to change to the 100th day of this year (whether before or after):
+
+```js
+function getDayInSameYear(date, destDayOfYear) {
+  return date.add({ days: destDayOfYear - date.dayOfYear });
+}
+
+console.log(
+  getDayInSameYear(Temporal.PlainDate.from("2021-07-01"), 100).toString(),
+); // 2021-04-10
+console.log(
+  getDayInSameYear(Temporal.PlainDate.from("2021-01-01"), 100).toString(),
+); // 2021-04-10
+console.log(
+  getDayInSameYear(Temporal.PlainDate.from("2020-01-01"), 100).toString(),
+); // 2020-04-09
+```
+
+By default, `with()` constrains the day to the range of valid values. So you can always use `{ month: 1, day: 1 }` to set the day to the first day of the year, even if the first day does not have the number `1`. Similarly, the following will set the day to the last day of the year, regardless of how many days are in the last month or year:
+
+```js
+const date = Temporal.PlainDate.from("2021-07-01");
+const lastDay = date.with({ month: Number.MAX_VALUE, day: Number.MAX_VALUE }); // 2021-12-31
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal/PlainDate/with", "Temporal.PlainDate.prototype.with()")}}
+- {{jsxref("Temporal/PlainDate/add", "Temporal.PlainDate.prototype.add()")}}
+- {{jsxref("Temporal/PlainDate/subtract", "Temporal.PlainDate.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainDate/year", "Temporal.PlainDate.prototype.year")}}
+- {{jsxref("Temporal/PlainDate/day", "Temporal.PlainDate.prototype.day")}}
+- {{jsxref("Temporal/PlainDate/dayOfWeek", "Temporal.PlainDate.prototype.dayOfWeek")}}
+- {{jsxref("Temporal/PlainDate/daysInYear", "Temporal.PlainDate.prototype.daysInYear")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/daysinmonth/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/daysinmonth/index.md
new file mode 100644
index 000000000000000..fa5ebb2f9ca710e
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/daysinmonth/index.md
@@ -0,0 +1,75 @@
+---
+title: Temporal.PlainDate.prototype.daysInMonth
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate/daysInMonth
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDate.daysInMonth
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`daysInMonth`** accessor property of {{jsxref("Temporal.PlainDate")}} instances returns a positive integer representing the number of days in the month of this date. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+Note that the days in month is not always equal to the {{jsxref("Temporal/PlainDate/day", "day")}} of the last day of the month, in the rare case where a month may have a few days skipped.
+
+The set accessor of `daysInMonth` is `undefined`. You cannot change this property directly.
+
+## Examples
+
+### Using daysInMonth
+
+```js
+const date = Temporal.PlainDate.from("2021-07-01");
+console.log(date.daysInMonth); // 31
+
+const date2 = Temporal.PlainDate.from("2021-02-01");
+console.log(date2.daysInMonth); // 28; 2021 is not a leap year
+
+const date3 = Temporal.PlainDate.from("2020-02-01");
+console.log(date3.daysInMonth); // 29; 2020 is a leap year
+
+const date4 = Temporal.PlainDate.from("2021-04-01[u-ca=chinese]");
+console.log(date4.month); // 2
+console.log(date4.daysInMonth); // 30; the Chinese 2nd month has 30 days
+```
+
+### Changing to the second last day of the month
+
+You can use `daysInMonth` to change to the second last day of the month:
+
+```js
+const date = Temporal.PlainDate.from("2021-07-01");
+const secondLastDay = date.with({ day: date.daysInMonth - 1 });
+console.log(secondLastDay.toString()); // 2021-07-30
+```
+
+This is not totally safe, though, because `daysInMonth` is not guaranteed to have any connection with the day index. Here's a safer way to get the second last day:
+
+```js
+const date = Temporal.PlainDate.from("2021-07-01");
+const secondLastDay = date
+  .with({ day: Number.MAX_SAFE_INTEGER })
+  .subtract({ days: 1 });
+console.log(secondLastDay.toString()); // 2021-07-30
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal/PlainDate/with", "Temporal.PlainDate.prototype.with()")}}
+- {{jsxref("Temporal/PlainDate/add", "Temporal.PlainDate.prototype.add()")}}
+- {{jsxref("Temporal/PlainDate/subtract", "Temporal.PlainDate.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainDate/year", "Temporal.PlainDate.prototype.year")}}
+- {{jsxref("Temporal/PlainDate/month", "Temporal.PlainDate.prototype.month")}}
+- {{jsxref("Temporal/PlainDate/day", "Temporal.PlainDate.prototype.day")}}
+- {{jsxref("Temporal/PlainDate/daysInWeek", "Temporal.PlainDate.prototype.daysInWeek")}}
+- {{jsxref("Temporal/PlainDate/daysInYear", "Temporal.PlainDate.prototype.daysInYear")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/daysinweek/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/daysinweek/index.md
new file mode 100644
index 000000000000000..dbbe0acceb76a47
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/daysinweek/index.md
@@ -0,0 +1,48 @@
+---
+title: Temporal.PlainDate.prototype.daysInWeek
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate/daysInWeek
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDate.daysInWeek
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`daysInWeek`** accessor property of {{jsxref("Temporal.PlainDate")}} instances returns a positive integer representing the number of days in the week of this date. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+For the ISO 8601 calendar, this is always 7, but in other calendar systems it may differ from week to week. All commonly supported calendars use 7-day weeks.
+
+The set accessor of `daysInWeek` is `undefined`. You cannot change this property directly.
+
+## Examples
+
+### Using daysInWeek
+
+```js
+const date = Temporal.PlainDate.from("2021-07-01");
+console.log(date.daysInWeek); // 7
+
+const date2 = Temporal.PlainDate.from("2021-07-01[u-ca=chinese]");
+console.log(date2.daysInWeek); // 7
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal/PlainDate/with", "Temporal.PlainDate.prototype.with()")}}
+- {{jsxref("Temporal/PlainDate/add", "Temporal.PlainDate.prototype.add()")}}
+- {{jsxref("Temporal/PlainDate/subtract", "Temporal.PlainDate.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainDate/yearOfWeek", "Temporal.PlainDate.prototype.yearOfWeek")}}
+- {{jsxref("Temporal/PlainDate/weekOfYear", "Temporal.PlainDate.prototype.weekOfYear")}}
+- {{jsxref("Temporal/PlainDate/dayOfWeek", "Temporal.PlainDate.prototype.dayOfWeek")}}
+- {{jsxref("Temporal/PlainDate/daysInMonth", "Temporal.PlainDate.prototype.daysInMonth")}}
+- {{jsxref("Temporal/PlainDate/daysInYear", "Temporal.PlainDate.prototype.daysInYear")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/daysinyear/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/daysinyear/index.md
new file mode 100644
index 000000000000000..e1348db7b94d1c6
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/daysinyear/index.md
@@ -0,0 +1,53 @@
+---
+title: Temporal.PlainDate.prototype.daysInYear
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate/daysInYear
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDate.daysInYear
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`daysInYear`** accessor property of {{jsxref("Temporal.PlainDate")}} instances returns a positive integer representing the number of days in the year of this date. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+For the ISO 8601 calendar, this is 365, or 366 in a leap year. In other calendar systems, it likely differs, especially in non-solar calendars.
+
+The set accessor of `daysInWeek` is `undefined`. You cannot change this property directly.
+
+## Examples
+
+### Using daysInYear
+
+```js
+const date = Temporal.PlainDate.from("2021-07-01");
+console.log(date.daysInYear); // 365
+
+const date2 = Temporal.PlainDate.from("2020-07-01");
+console.log(date2.daysInYear); // 366; 2020 is a leap year
+
+const date3 = Temporal.PlainDate.from("2021-07-01[u-ca=chinese]");
+console.log(date3.daysInYear); // 354
+
+const date4 = Temporal.PlainDate.from("2023-07-01[u-ca=chinese]");
+console.log(date4.daysInYear); // 384; 2023 is a Chinese leap year
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal/PlainDate/with", "Temporal.PlainDate.prototype.with()")}}
+- {{jsxref("Temporal/PlainDate/add", "Temporal.PlainDate.prototype.add()")}}
+- {{jsxref("Temporal/PlainDate/subtract", "Temporal.PlainDate.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainDate/year", "Temporal.PlainDate.prototype.year")}}
+- {{jsxref("Temporal/PlainDate/dayOfYear", "Temporal.PlainDate.prototype.dayOfYear")}}
+- {{jsxref("Temporal/PlainDate/daysInMonth", "Temporal.PlainDate.prototype.daysInMonth")}}
+- {{jsxref("Temporal/PlainDate/daysInWeek", "Temporal.PlainDate.prototype.daysInWeek")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/equals/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/equals/index.md
new file mode 100644
index 000000000000000..aa4c00a25c37a0f
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/equals/index.md
@@ -0,0 +1,56 @@
+---
+title: Temporal.PlainDate.prototype.equals()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate/equals
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDate.equals
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`equals()`** method of {{jsxref("Temporal.PlainDate")}} instances returns `true` if this date is equivalent in value to another date (in a form convertible by {{jsxref("Temporal/PlainDate/from", "Temporal.PlainDate.from()")}}), and `false` otherwise. They are compared both by their date values and their calendars, so two dates from different calendars may be considered equal by {{jsxref("Temporal/PlainDate/compare", "Temporal.PlainDate.compare()")}} but not by `equals()`.
+
+## Syntax
+
+```js-nolint
+equals(other)
+```
+
+### Parameters
+
+- `other`
+  - : A string, an object, or a {{jsxref("Temporal.PlainDate")}} instance representing the other date to compare. It is converted to a `Temporal.PlainDate` object using the same algorithm as {{jsxref("Temporal/PlainDate/from", "Temporal.PlainDate.from()")}}.
+
+### Return value
+
+`true` if this date is equal to `other` both in their date value and their calendar, `false` otherwise.
+
+## Examples
+
+### Using equals()
+
+```js
+const date1 = Temporal.PlainDate.from("2021-08-01");
+const date2 = Temporal.PlainDate.from({ year: 2021, month: 8, day: 1 });
+console.log(date1.equals(date2)); // true
+
+const date3 = Temporal.PlainDate.from("2021-08-01[u-ca=japanese]");
+console.log(date1.equals(date3)); // false
+
+const date4 = Temporal.PlainDate.from("2021-08-02");
+console.log(date1.equals(date4)); // false
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal/PlainDate/compare", "Temporal.PlainDate.compare()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/era/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/era/index.md
new file mode 100644
index 000000000000000..fc3d958eda113f8
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/era/index.md
@@ -0,0 +1,66 @@
+---
+title: Temporal.PlainDate.prototype.era
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate/era
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDate.era
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`era`** accessor property of {{jsxref("Temporal.PlainDate")}} instances returns a calendar-specific lowercase string representing the era of this date, or `undefined` if the calendar does not use eras (e.g. ISO 8601). `era` and `eraYear` together uniquely identify a year in a calendar, in the same way that `year` does. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. For Gregorian, it is either `"gregory"` or `"gregory-inverse"`.
+
+The set accessor of `era` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/PlainDate/with", "with()")}} method to create a new `Temporal.PlainDate` object with the desired new value. When setting eras, each code may have some aliases; for example, `"ce"` and `"ad"` are equivalent to `"gregory"`, and `"bce"` and `"bc"` are equivalent to `"gregory-inverse"`.
+
+> [!NOTE]
+> This string is not intended for display to users. Use {{jsxref("Temporal/PlainDate/toLocaleString", "toLocaleString()")}} with the appropriate options to get a localized string.
+
+## Examples
+
+### Using era
+
+```js
+const date = Temporal.PlainDate.from("2021-07-01"); // ISO 8601 calendar
+console.log(date.era); // undefined
+
+const date2 = Temporal.PlainDate.from("2021-07-01[u-ca=gregory]");
+console.log(date2.era); // gregory
+
+const date3 = Temporal.PlainDate.from("-002021-07-01[u-ca=gregory]");
+console.log(date3.era); // gregory-inverse
+
+const date4 = Temporal.PlainDate.from("2021-07-01[u-ca=japanese]");
+console.log(date4.era); // reiwa
+```
+
+### Changing era
+
+You can only set `era` for calendars that support them. For example, the ISO 8601 calendar does not have eras. Note that you must provide `era` and `eraYear` together.
+
+```js
+const date = Temporal.PlainDate.from("2021-07-01[u-ca=gregory]");
+const newDate = date.with({ era: "bc", eraYear: 100 });
+console.log(newDate.toString()); // -000099-07-01[u-ca=gregory]
+
+const date2 = Temporal.PlainDate.from("2021-07-01[u-ca=japanese]");
+const newDate2 = date2.with({ era: "meiji", eraYear: 1 });
+console.log(newDate2.toString()); // 1868-07-01[u-ca=japanese]
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal/PlainDate/with", "Temporal.PlainDate.prototype.with()")}}
+- {{jsxref("Temporal/PlainDate/add", "Temporal.PlainDate.prototype.add()")}}
+- {{jsxref("Temporal/PlainDate/subtract", "Temporal.PlainDate.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainDate/year", "Temporal.PlainDate.prototype.year")}}
+- {{jsxref("Temporal/PlainDate/eraYear", "Temporal.PlainDate.prototype.eraYear")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/erayear/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/erayear/index.md
new file mode 100644
index 000000000000000..0ed270062d8f866
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/erayear/index.md
@@ -0,0 +1,65 @@
+---
+title: Temporal.PlainDate.prototype.eraYear
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate/eraYear
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDate.eraYear
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`eraYear`** accessor property of {{jsxref("Temporal.PlainDate")}} instances returns a non-negative integer representing the year of this date within the era, or `undefined` if the calendar does not use eras (e.g. ISO 8601). The year index usually starts from 1 (more common) or 0, and years in an era can decrease with time (e.g. Gregorian BCE). `era` and `eraYear` together uniquely identify a year in a calendar, in the same way that `year` does. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+Unlike `year`, `era` and `eraYear` may change in the middle of a calendar year. For example, Japan started the Reiwa era on May 1, 2019, so dates from 2019-01-01 to 2019-04-30 have `{ era: "heisei", eraYear: 31 }`, and dates from 2019-05-01 onwards have `{ era: "reiwa", eraYear: 1 }`, but the `year` is always 2019 (because the Japanese calendar uses the ISO 8601 year as the default year).
+
+The set accessor of `eraYear` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/PlainDate/with", "with()")}} method to create a new `Temporal.PlainDate` object with the desired new value.
+
+## Examples
+
+### Using eraYear
+
+```js
+const date = Temporal.PlainDate.from("2021-07-01"); // ISO 8601 calendar
+console.log(date.eraYear); // undefined
+
+const date2 = Temporal.PlainDate.from("2021-07-01[u-ca=gregory]");
+console.log(date2.eraYear); // 2021
+
+const date3 = Temporal.PlainDate.from("-002021-07-01[u-ca=gregory]");
+console.log(date3.eraYear); // 2022; 0000 is used for the year 1 BC
+
+const date4 = Temporal.PlainDate.from("2021-07-01[u-ca=japanese]");
+console.log(date4.eraYear); // 3
+```
+
+### Changing eraYear
+
+You can only set `eraYear` for calendars that support them. For example, the ISO 8601 calendar does not have eras. Note that you must provide `era` and `eraYear` together.
+
+```js
+const date = Temporal.PlainDate.from("2021-07-01[u-ca=gregory]");
+const newDate = date.with({ era: "bc", eraYear: 100 });
+console.log(newDate.toString()); // -000099-07-01[u-ca=gregory]
+
+const date2 = Temporal.PlainDate.from("2021-07-01[u-ca=japanese]");
+const newDate2 = date2.with({ era: "meiji", eraYear: 1 });
+console.log(newDate2.toString()); // 1868-07-01[u-ca=japanese]
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal/PlainDate/with", "Temporal.PlainDate.prototype.with()")}}
+- {{jsxref("Temporal/PlainDate/add", "Temporal.PlainDate.prototype.add()")}}
+- {{jsxref("Temporal/PlainDate/subtract", "Temporal.PlainDate.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainDate/year", "Temporal.PlainDate.prototype.year")}}
+- {{jsxref("Temporal/PlainDate/era", "Temporal.PlainDate.prototype.era")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/from/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/from/index.md
new file mode 100644
index 000000000000000..8e9409e3ee64400
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/from/index.md
@@ -0,0 +1,184 @@
+---
+title: Temporal.PlainDate.from()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate/from
+page-type: javascript-static-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDate.from
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.PlainDate.from()`** static method creates a new `Temporal.PlainDate` object from another `Temporal.PlainDate` object, an object with date properties, or an [RFC 9557](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate#rfc_9557_format) string.
+
+## Syntax
+
+```js-nolint
+Temporal.PlainDate.from(info)
+Temporal.PlainDate.from(info, options)
+```
+
+### Parameters
+
+- `info`
+
+  - : One of the following:
+
+    - A {{jsxref("Temporal.PlainDate")}} instance, which creates a copy of the instance.
+    - A {{jsxref("Temporal.PlainDateTime")}} instance, which provides the calendar date in the same fashion as {{jsxref("Temporal/PlainDateTime/toPlainDate", "Temporal.PlainDateTime.prototype.toPlainDate()")}}.
+    - A {{jsxref("Temporal.ZonedDateTime")}} instance, which provides the calendar date in the same fashion as {{jsxref("Temporal/ZonedDateTime/toPlainDate", "Temporal.ZonedDateTime.prototype.toPlainDate()")}}.
+    - An [RFC 9557](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate#rfc_9557_format) string containing a date and optionally a calendar.
+    - An object containing the following properties (in the order they are retrieved and validated):
+
+      - `calendar` {{optional_inline}}
+        - : A string that corresponds to the {{jsxref("Temporal/PlainDate/calendarId", "calendarId")}} property. Defaults to `"iso8601"`. All other properties are interpreted in this calendar system (unlike the {{jsxref("Temporal/PlainDate/PlainDate", "Temporal.PlainDate()")}} constructor, which interprets the values in the ISO calendar system).
+      - `day`
+        - : An integer that corresponds to the {{jsxref("Temporal/PlainDate/day", "day")}} property. Must be positive regardless of the `overflow` option.
+      - `era` and `eraYear`
+        - : A string and an integer that correspond to the {{jsxref("Temporal/PlainDate/era", "era")}} and {{jsxref("Temporal/PlainDate/eraYear", "eraYear")}} properties. Are only used if the calendar system has eras. `era` and `eraYear` must be provided simultaneously. At least one of `era`+`eraYear` or `year` must be provided. If all of `era`, `eraYear`, and `year` are provided, they must be consistent.
+      - `month`
+        - : Corresponds to the {{jsxref("Temporal/PlainDate/month", "month")}} property. Must be positive regardless of the `overflow` option. At least one of `month` or `monthCode` must be provided. If both `month` and `monthCode` are provided, they must be consistent.
+      - `monthCode`
+        - : Corresponds to the {{jsxref("Temporal/PlainDate/monthCode", "monthCode")}} property. At least one of `month` or `monthCode` must be provided. If both `month` and `monthCode` are provided, they must be consistent.
+      - `year`
+        - : Corresponds to the {{jsxref("Temporal/PlainDate/year", "year")}} property. At least one of `era`+`eraYear` or `year` must be provided. If all of `era`, `eraYear`, and `year` are provided, they must be consistent.
+
+      The info should explicitly specify a year (as `year` or `era` and `eraYear`), a month (as `month` or `monthCode`), and a day.
+
+- `options` {{optional_inline}}
+  - : An object containing the following property:
+    - `overflow` {{optional_inline}}
+      - : A string specifying the behavior when a date component is out of range (when using the object `info`). Possible values are:
+        - `"constrain"` (default)
+          - : The date component is [clamped](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate#invalid_date_clamping) to the valid range.
+        - `"reject"`
+          - : A {{jsxref("RangeError")}} is thrown if the date component is out of range.
+
+### Return value
+
+A new `Temporal.PlainDate` object, representing the date specified by `info` in the specified `calendar`.
+
+### Exceptions
+
+- {{jsxref("TypeError")}}
+  - : Thrown in one of the following cases:
+    - `info` is not an object or a string.
+    - `options` is not an object or `undefined`.
+    - The provided properties are insufficient to unambiguously determine a date. You usually need to provide a `year` (or `era` and `eraYear`), a `month` (or `monthCode`), and a `day`.
+- {{jsxref("RangeError")}}
+  - : Thrown in one of the following cases:
+    - The provided properties that specify the same component are inconsistent.
+    - The provided non-numerical properties are not valid; for example, if `monthCode` is never a valid month code in this calendar.
+    - The provided numerical properties are out of range, and `options.overflow` is set to `"reject"`.
+
+## Examples
+
+### Creating a PlainDate from an object
+
+```js
+// Year, month, and day
+const d1 = Temporal.PlainDate.from({ year: 2021, month: 7, day: 1 });
+console.log(d1.toString()); // "2021-07-01"
+
+// Year, month code, and day
+const d2 = Temporal.PlainDate.from({ year: 2021, monthCode: "M07", day: 1 });
+console.log(d2.toString()); // "2021-07-01"
+
+// Year, month, day in a different calendar
+const d3 = Temporal.PlainDate.from({
+  year: 2021,
+  month: 7,
+  day: 1,
+  calendar: "chinese",
+});
+// Note: when you construct a date with an object, the date components
+// are in *that* calendar, not the ISO calendar. However, toString() always
+// outputs the date in the ISO calendar. For example, the year "2021" in
+// the Chinese calendar is actually 616 BC in the ISO calendar.
+console.log(d3.toString()); // "-000616-08-12[u-ca=chinese]"
+
+// Era, eraYear, month, and day
+const d4 = Temporal.PlainDate.from({
+  era: "meiji",
+  eraYear: 4,
+  month: 7,
+  day: 1,
+  calendar: "japanese",
+});
+console.log(d4.toString()); // "1871-07-01[u-ca=japanese]"
+```
+
+### Controlling overflow behavior
+
+By default, out-of-range values are clamped to the valid range:
+
+```js
+const d1 = Temporal.PlainDate.from({ year: 2021, month: 13, day: 1 });
+console.log(d1.toString()); // "2021-12-01"
+
+const d2 = Temporal.PlainDate.from({ year: 2021, month: 2, day: 29 });
+console.log(d2.toString()); // "2021-02-28"
+
+const d3 = Temporal.PlainDate.from("2021-02-29");
+console.log(d3.toString()); // "2021-02-28"
+```
+
+You can change this behavior to throw an error instead:
+
+```js
+const d3 = Temporal.PlainDate.from(
+  { year: 2021, month: 13, day: 1 },
+  { overflow: "reject" },
+);
+// RangeError: date value "month" not in 1..12: 13
+```
+
+### Creating a PlainDate from a string
+
+```js
+const d = Temporal.PlainDate.from("2021-07-01");
+console.log(d.toLocaleString("en-US", { dateStyle: "full" }));
+// Thursday, July 1, 2021
+
+// Providing a calendar
+const d2 = Temporal.PlainDate.from("2021-07-01[u-ca=japanese]");
+console.log(
+  d2.toLocaleString("ja-JP", { calendar: "japanese", dateStyle: "full" }),
+);
+// 令和3年7月1日木曜日
+
+// Providing a time and an offset (ignored)
+const d3 = Temporal.PlainDate.from("2021-07-01T00:00+08:00");
+console.log(d3.toString()); // "2021-07-01"
+```
+
+### Creating a PlainDate from another Temporal instance
+
+```js
+const dt = Temporal.PlainDateTime.from("2021-07-01T12:00");
+const d = Temporal.PlainDate.from(dt);
+console.log(d.toString()); // "2021-07-01"
+
+const zdt = Temporal.ZonedDateTime.from(
+  "2021-07-01T00:00+08:00[Asia/Shanghai]",
+);
+const d2 = Temporal.PlainDate.from(zdt);
+console.log(d2.toString()); // "2021-07-01"
+
+const d3 = Temporal.PlainDate.from(d);
+console.log(d3.toString()); // "2021-07-01"
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal/PlainDate/PlainDate", "Temporal.PlainDate()")}}
+- {{jsxref("Temporal/PlainDate/with", "Temporal.PlainDate.prototype.with()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/index.md
new file mode 100644
index 000000000000000..03a9e13d85891a7
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/index.md
@@ -0,0 +1,149 @@
+---
+title: Temporal.PlainDate
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate
+page-type: javascript-class
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDate
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.PlainDate`** object represents a calendar date (a date without a time or time zone); for example, an event on a calendar which happens during the whole day no matter which time zone it's happening in. It is fundamentally represented as an ISO 8601 calendar date, with year, month, and day fields, and an associated calendar system.
+
+## Description
+
+A `PlainDate` is essentially the date part of a {{jsxref("Temporal.PlainDateTime")}} object, with the time information removed. Because the date and time information don't have much interaction, all general information about date properties is documented here.
+
+### RFC 9557 format
+
+`PlainDate` objects can be serialized and parsed using the [RFC 9557](https://datatracker.ietf.org/doc/html/rfc9557) format, an extension to the [ISO 8601 / RFC 3339](https://datatracker.ietf.org/doc/html/rfc3339) format. The string has the following form (spaces are only for readability and should not be present in the actual string):
+
+```plain
+YYYY-MM-DD [u-ca=calendar_id]
+```
+
+- `YYYY`
+  - : Either a four-digit number, or a six-digit number with a `+` or `-` sign.
+- `MM`
+  - : A two-digit number from `01` to `12`.
+- `DD`
+  - : A two-digit number from `01` to `31`. The `YYYY`, `MM`, and `DD` components can be separated by `-` or nothing.
+- `[u-ca=calendar_id]` {{optional_inline}}
+  - : Replace `calendar_id` with the calendar to use. May have a _critical flag_ by prefixing the key with `!`: e.g., `[!u-ca=iso8601]`. This flag generally tells other systems that it cannot be ignored if they don't support it. The `Temporal` parser will throw an error if the annotations contain two or more calendar annotations and one of them is critical. Defaults to `[u-ca=iso8601]`. Note that the `YYYY-MM-DD` is always interpreted as an ISO 8601 calendar date and then converted to the specified calendar.
+
+As an input, you may optionally include the time, offset, and time zone identifier, in the same format as [`PlainDateTime`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime#rfc_9557_format), but they will be ignored. Other annotations in the `[key=value]` format are also ignored, and they must not have the critical flag.
+
+When serializing, you can configure whether to display the calendar ID, and whether to add a critical flag for it.
+
+### Invalid date clamping
+
+The {{jsxref("Temporal/PlainDate/from", "Temporal.PlainDate.from()")}}, {{jsxref("Temporal/PlainDate/with", "Temporal.PlainDate.prototype.with()")}}, {{jsxref("Temporal/PlainDate/add", "Temporal.PlainDate.prototype.add()")}}, {{jsxref("Temporal/PlainDate/subtract", "Temporal.PlainDate.prototype.subtract()")}} methods, and their counterparts in other `Temporal` objects, allow constructing dates using calendar-specific properties. The date components may be out of range. In the ISO calendar, this is always an _overflow_, such as the month being greater than 12 or the day being greater than the number of days, and fixing it would only involve clamping the value to the maximum allowed value. In other calendars, the invalid case may be more complex. When using the `overflow: "constrain"` option, invalid dates are fixed to a valid one in the following way:
+
+- If the day doesn't exist but the month does: pick the closest day in the same month. If there are two equally-close dates in that month, pick the later one.
+- If the month is a leap month that doesn't exist in the year: pick another date according to the cultural conventions of that calendar's users. Usually this will result in the same day in the month before or after where that month would normally fall in a leap year.
+- If the month doesn't exist in the year for other reasons: pick the closest date that is still in the same year. If there are two equally-close dates in that year, pick the later one.
+- If the entire year doesn't exist: pick the closest date in a different year. If there are two equally-close dates, pick the later one.
+
+## Constructor
+
+- {{jsxref("Temporal/PlainDate/PlainDate", "Temporal.PlainDate()")}} {{experimental_inline}}
+  - : Creates a new `Temporal.PlainDate` object by directly supplying the underlying data.
+
+## Static methods
+
+- {{jsxref("Temporal/PlainDate/compare", "Temporal.PlainDate.compare()")}} {{experimental_inline}}
+  - : Returns a number (-1, 0, or 1) indicating whether the first date comes before, is the same as, or comes after the second date. Equivalent to comparing the year, month, and day fields of the underlying ISO 8601 dates.
+- {{jsxref("Temporal/PlainDate/from", "Temporal.PlainDate.from()")}} {{experimental_inline}}
+  - : Creates a new `Temporal.PlainDate` object from another `Temporal.PlainDate` object, an object with date properties, or an [RFC 9557](#rfc_9557_format) string.
+
+## Instance properties
+
+These properties are defined on `Temporal.PlainDate.prototype` and shared by all `Temporal.PlainDate` instances.
+
+- {{jsxref("Temporal/PlainDate/calendarId", "Temporal.PlainDate.prototype.calendarId")}} {{experimental_inline}}
+  - : Returns a string representing the [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars) used to interpret the internal ISO 8601 date.
+- {{jsxref("Object/constructor", "Temporal.PlainDate.prototype.constructor")}}
+  - : The constructor function that created the instance object. For `Temporal.PlainDate` instances, the initial value is the {{jsxref("Temporal/PlainDate/PlainDate", "Temporal.PlainDate()")}} constructor.
+- {{jsxref("Temporal/PlainDate/day", "Temporal.PlainDate.prototype.day")}} {{experimental_inline}}
+  - : Returns a positive integer representing the 1-based day index in the month of this date, which is the same day number you would see on a calendar. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. Generally starts at 1 and is continuous, but not always.
+- {{jsxref("Temporal/PlainDate/dayOfWeek", "Temporal.PlainDate.prototype.dayOfWeek")}} {{experimental_inline}}
+  - : Returns a positive integer representing the 1-based day index in the week of this date. Days in a week are numbered sequentially from `1` to {{jsxref("Temporal/PlainDate/daysInWeek", "daysInWeek")}}, with each number mapping to its name. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. 1 usually represents Monday in the calendar, even when locales using the calendar may consider a different day as the first day of the week (see {{jsxref("Intl/Locale/getWeekInfo", "Intl.Locale.prototype.getWeekInfo()")}}).
+- {{jsxref("Temporal/PlainDate/dayOfYear", "Temporal.PlainDate.prototype.dayOfYear")}} {{experimental_inline}}
+  - : Returns a positive integer representing the 1-based day index in the year of this date. The first day of this year is `1`, and the last day is the {{jsxref("Temporal/PlainDate/daysInYear", "daysInYear")}}. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+- {{jsxref("Temporal/PlainDate/daysInMonth", "Temporal.PlainDate.prototype.daysInMonth")}} {{experimental_inline}}
+  - : Returns a positive integer representing the number of days in the month of this date. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+- {{jsxref("Temporal/PlainDate/daysInWeek", "Temporal.PlainDate.prototype.daysInWeek")}} {{experimental_inline}}
+  - : Returns a positive integer representing the number of days in the week of this date. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. For the ISO 8601 calendar, this is always 7, but in other calendar systems it may differ from week to week.
+- {{jsxref("Temporal/PlainDate/daysInYear", "Temporal.PlainDate.prototype.daysInYear")}} {{experimental_inline}}
+  - : Returns a positive integer representing the number of days in the year of this date. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. For the ISO 8601 calendar, this is 365, or 366 in a leap year.
+- {{jsxref("Temporal/PlainDate/era", "Temporal.PlainDate.prototype.era")}} {{experimental_inline}}
+  - : Returns a calendar-specific lowercase string representing the era of this date, or `undefined` if the calendar does not use eras (e.g. ISO 8601). `era` and `eraYear` together uniquely identify a year in a calendar, in the same way that `year` does. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. For Gregorian, it is either `"gregory"` or `"gregory-inverse"`.
+- {{jsxref("Temporal/PlainDate/eraYear", "Temporal.PlainDate.prototype.eraYear")}} {{experimental_inline}}
+  - : Returns a non-negative integer representing the year of this date within the era, or `undefined` if the calendar does not use eras (e.g. ISO 8601). The year index usually starts from 1 (more common) or 0, and years in an era can decrease with time (e.g. Gregorian BCE). `era` and `eraYear` together uniquely identify a year in a calendar, in the same way that `year` does. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+- {{jsxref("Temporal/PlainDate/inLeapYear", "Temporal.PlainDate.prototype.inLeapYear")}} {{experimental_inline}}
+  - : Returns a boolean indicating whether this date is in a leap year. A leap year is a year that has more days (due to a leap day or leap month) than a common year. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+- {{jsxref("Temporal/PlainDate/month", "Temporal.PlainDate.prototype.month")}} {{experimental_inline}}
+  - : Returns a positive integer representing the 1-based month index in the year of this date. The first month of this year is `1`, and the last month is the {{jsxref("Temporal/PlainDate/monthsInYear", "monthsInYear")}}. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. Note that unlike {{jsxref("Date.prototype.getMonth()")}}, the index is 1-based. If the calendar has leap months, then the month with the same {{jsxref("Temporal/PlainDate/monthCode", "monthCode")}} may have different `month` indexes for different years.
+- {{jsxref("Temporal/PlainDate/monthCode", "Temporal.PlainDate.prototype.monthCode")}} {{experimental_inline}}
+  - : Returns a calendar-specific string representing the month of this date. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. Usually it is `M` plus a two-digit month number. For leap months, it is the previous month's code followed by `L`. If the leap month is the first month of the year, the code is `M00L`.
+- {{jsxref("Temporal/PlainDate/monthsInYear", "Temporal.PlainDate.prototype.monthsInYear")}} {{experimental_inline}}
+  - : Returns a positive integer representing the number of months in the year of this date. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. For the ISO 8601 calendar, this is always 12, but in other calendar systems it may differ.
+- {{jsxref("Temporal/PlainDate/weekOfYear", "Temporal.PlainDate.prototype.weekOfYear")}} {{experimental_inline}}
+  - : Returns a positive integer representing the 1-based week index in the {{jsxref("Temporal/PlainDate/yearOfWeek", "yearOfWeek")}} of this date, or `undefined` if the calendar does not have a well-defined week system. The first week of the year is `1`. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. Note that for ISO 8601, the first and last few days of the year may be attributed to the last week of the previous year or the first week of the next year.
+- {{jsxref("Temporal/PlainDate/year", "Temporal.PlainDate.prototype.year")}} {{experimental_inline}}
+  - : Returns an integer representing the number of years of this date relative to the start of a calendar-specific epoch year. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. Usually year 1 is either the first year of the latest era or the ISO 8601 year `0001`. If the epoch is in the middle of the year, that year will have the same value before and after the start date of the era.
+- {{jsxref("Temporal/PlainDate/yearOfWeek", "Temporal.PlainDate.prototype.yearOfWeek")}} {{experimental_inline}}
+  - : Returns an integer representing the year to be paired with the {{jsxref("Temporal/PlainDate/weekOfYear", "weekOfYear")}} of this date, or `undefined` if the calendar does not have a well-defined week system. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. Usually this is the year of the date, but for ISO 8601, the first and last few days of the year may be attributed to the last week of the previous year or the first week of the next year, causing the `yearOfWeek` to differ by 1.
+- `Temporal.PlainDate.prototype[Symbol.toStringTag]`
+  - : The initial value of the [`[Symbol.toStringTag]`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol/toStringTag) property is the string `"Temporal.PlainDate"`. This property is used in {{jsxref("Object.prototype.toString()")}}.
+
+## Instance methods
+
+- {{jsxref("Temporal/PlainDate/add", "Temporal.PlainDate.prototype.add()")}} {{experimental_inline}}
+  - : Returns a new `Temporal.PlainDate` object representing this date moved forward by a given duration (in a form convertible by {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}).
+- {{jsxref("Temporal/PlainDate/equals", "Temporal.PlainDate.prototype.equals()")}} {{experimental_inline}}
+  - : Returns `true` if this date is equivalent in value to another date (in a form convertible by {{jsxref("Temporal/PlainDate/from", "Temporal.PlainDate.from()")}}), and `false` otherwise. They are compared both by their date values and their calendars.
+- {{jsxref("Temporal/PlainDate/since", "Temporal.PlainDate.prototype.since()")}} {{experimental_inline}}
+  - : Returns a new {{jsxref("Temporal.Duration")}} object representing the duration from another date (in a form convertible by {{jsxref("Temporal/PlainDate/from", "Temporal.PlainDate.from()")}}) to this date. The duration is positive if the other date is before this date, and negative if after.
+- {{jsxref("Temporal/PlainDate/subtract", "Temporal.PlainDate.prototype.subtract()")}} {{experimental_inline}}
+  - : Returns a new `Temporal.PlainDate` object representing this date moved backward by a given duration (in a form convertible by {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}).
+- {{jsxref("Temporal/PlainDate/toJSON", "Temporal.PlainDate.prototype.toJSON()")}} {{experimental_inline}}
+  - : Returns a string representing this date in the same [RFC 9557 format](#rfc_9557_format) as calling {{jsxref("Temporal/PlainDate/toString", "toString()")}}. Intended to be implicitly called by {{jsxref("JSON.stringify()")}}.
+- {{jsxref("Temporal/PlainDate/toLocaleString", "Temporal.PlainDate.prototype.toLocaleString()")}} {{experimental_inline}}
+  - : Returns a string with a language-sensitive representation of this date.
+- {{jsxref("Temporal/PlainDate/toPlainDateTime", "Temporal.PlainDate.prototype.toPlainDateTime()")}} {{experimental_inline}}
+  - : Returns a new {{jsxref("Temporal.PlainDateTime")}} object representing this date and a supplied time in the same calendar system.
+- {{jsxref("Temporal/PlainDate/toPlainMonthDay", "Temporal.PlainDate.prototype.toPlainMonthDay()")}} {{experimental_inline}}
+  - : Returns a new {{jsxref("Temporal.PlainMonthDay")}} object representing the {{jsxref("Temporal/PlainDate/monthCode", "monthCode")}} and {{jsxref("Temporal/PlainDate/day", "day")}} of this date in the same calendar system.
+- {{jsxref("Temporal/PlainDate/toPlainYearMonth", "Temporal.PlainDate.prototype.toPlainYearMonth()")}} {{experimental_inline}}
+  - : Returns a new {{jsxref("Temporal.PlainYearMonth")}} object representing the {{jsxref("Temporal/PlainDate/year", "year")}} and {{jsxref("Temporal/PlainDate/month", "month")}} of this date in the same calendar system.
+- {{jsxref("Temporal/PlainDate/toString", "Temporal.PlainDate.prototype.toString()")}} {{experimental_inline}}
+  - : Returns a string representing this date in the [RFC 9557 format](#rfc_9557_format).
+- {{jsxref("Temporal/PlainDate/toZonedDateTime", "Temporal.PlainDate.prototype.toZonedDateTime()")}} {{experimental_inline}}
+  - : Returns a new {{jsxref("Temporal.ZonedDateTime")}} object representing this date, a supplied time, and a supplied time zone, in the same calendar system.
+- {{jsxref("Temporal/PlainDate/until", "Temporal.PlainDate.prototype.until()")}} {{experimental_inline}}
+  - : Returns a new {{jsxref("Temporal.Duration")}} object representing the duration from this date to another date (in a form convertible by {{jsxref("Temporal/Instant/from", "Temporal.Instant.from()")}}). The duration is positive if the other date is after this date, and negative if before.
+- {{jsxref("Temporal/PlainDate/valueOf", "Temporal.PlainDate.prototype.valueOf()")}} {{experimental_inline}}
+  - : Throws a {{jsxref("TypeError")}}, which prevents `Temporal.PlainDate` instances from being [implicitly converted to primitives](/en-US/docs/Web/JavaScript/Data_structures#primitive_coercion) when used in arithmetic or comparison operations.
+- {{jsxref("Temporal/PlainDate/with", "Temporal.PlainDate.prototype.with()")}} {{experimental_inline}}
+  - : Returns a new `Temporal.PlainDate` object representing this date with some fields replaced by new values.
+- {{jsxref("Temporal/PlainDate/withCalendar", "Temporal.PlainDate.prototype.withCalendar()")}} {{experimental_inline}}
+  - : Returns a new `Temporal.PlainDate` object representing this date interpreted in the new calendar system.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal")}}
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal.PlainMonthDay")}}
+- {{jsxref("Temporal.PlainYearMonth")}}
+- {{jsxref("Temporal.ZonedDateTime")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/inleapyear/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/inleapyear/index.md
new file mode 100644
index 000000000000000..8fa1fa153590336
--- /dev/null
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@@ -0,0 +1,60 @@
+---
+title: Temporal.PlainDate.prototype.inLeapYear
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate/inLeapYear
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDate.inLeapYear
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`inLeapYear`** accessor property of {{jsxref("Temporal.PlainDate")}} instances returns a boolean indicating whether this date is in a leap year. A leap year is a year that has more days (due to a leap day or leap month) than a common year. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+For the ISO 8601 calendar, a leap year is a year that is evenly divisible by 4, except for years that are evenly divisible by 100, unless the year is also evenly divisible by 400. For the ISO 8601 calendar, leap years have 366 days, while common years have 365 days. For other calendar systems, the rules likely differ, and leap years may have more days added (such as a leap month).
+
+The set accessor of `inLeapYear` is `undefined`. You cannot change this property directly.
+
+## Examples
+
+### Using inLeapYear
+
+```js
+const date = Temporal.PlainDate.from("2021-07-01");
+console.log(date.inLeapYear); // false
+console.log(date.daysInYear); // 365
+console.log(date.monthsInYear); // 12
+
+const date2 = Temporal.PlainDate.from("2020-07-01");
+console.log(date2.inLeapYear); // true
+console.log(date2.daysInYear); // 366
+console.log(date2.monthsInYear); // 12
+
+const date3 = Temporal.PlainDate.from("2021-07-01[u-ca=chinese]");
+console.log(date3.inLeapYear); // false
+console.log(date3.daysInYear); // 354
+console.log(date3.monthsInYear); // 12
+
+const date4 = Temporal.PlainDate.from("2023-07-01[u-ca=chinese]");
+console.log(date4.inLeapYear); // true
+console.log(date4.daysInYear); // 384
+console.log(date4.monthsInYear); // 13
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal/PlainDate/with", "Temporal.PlainDate.prototype.with()")}}
+- {{jsxref("Temporal/PlainDate/add", "Temporal.PlainDate.prototype.add()")}}
+- {{jsxref("Temporal/PlainDate/subtract", "Temporal.PlainDate.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainDate/year", "Temporal.PlainDate.prototype.year")}}
+- {{jsxref("Temporal/PlainDate/daysInYear", "Temporal.PlainDate.prototype.daysInYear")}}
+- {{jsxref("Temporal/PlainDate/monthsInYear", "Temporal.PlainDate.prototype.monthsInYear")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/month/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/month/index.md
new file mode 100644
index 000000000000000..2d88083f8ea3e2f
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/month/index.md
@@ -0,0 +1,103 @@
+---
+title: Temporal.PlainDate.prototype.month
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate/month
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDate.month
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`month`** accessor property of {{jsxref("Temporal.PlainDate")}} instances returns a positive integer representing the 1-based month index in the year of this date. The first month of this year is `1`, and the last month is the {{jsxref("Temporal/PlainDate/monthsInYear", "monthsInYear")}}. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+Note that unlike {{jsxref("Date.prototype.getMonth()")}}, the index is 1-based. If the calendar has leap months, then the month with the same {{jsxref("Temporal/PlainDate/monthCode", "monthCode")}} may have different `month` indexes for different years.
+
+> [!NOTE]
+> Do not use this property to identify the actual month, including its name. Use {{jsxref("Temporal/PlainDate/monthCode", "monthCode")}} for that purpose. Use `month` only for identifying months within the context of a year, or to figure out their order.
+
+The set accessor of `month` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/PlainDate/with", "with()")}} method to create a new `Temporal.PlainDate` object with the desired new value.
+
+## Examples
+
+### Using month
+
+```js
+const date = Temporal.PlainDate.from("2021-07-01"); // ISO 8601 calendar
+console.log(date.monthCode); // "M07"
+console.log(date.month); // 7
+
+const date2 = Temporal.PlainDate.from("2021-05-01[u-ca=chinese]");
+console.log(date2.monthCode); // "M03"
+console.log(date2.month); // 3; it is March 20 in the Chinese calendar
+
+const date3 = Temporal.PlainDate.from("2023-05-01[u-ca=chinese]");
+console.log(date3.monthCode); // "M03"
+console.log(date3.month); // 4, although it is also March (M03)!
+
+const date4 = Temporal.PlainDate.from("2023-04-01[u-ca=chinese]");
+console.log(date4.monthCode); // "M02L"
+console.log(date4.month); // 3, this month is a leap month, i.e. a duplicate February
+```
+
+### Looping through all months in a year
+
+```js
+const year = Temporal.PlainDate.from("2021-07-14"); // An arbitrary date in the year
+for (
+  let month = year.with({ month: 1 });
+  month.year === year.year;
+  month = month.add({ months: 1 })
+) {
+  console.log(month.month);
+}
+
+// Alternatively, this is also a safe way (unlike the day example):
+for (let month = 1; month <= year.monthsInYear; month++) {
+  const monthDate = year.with({ month });
+}
+```
+
+### Changing month
+
+```js
+const date = Temporal.PlainDate.from("2021-07-01");
+const newDate = date.with({ month: 2 });
+console.log(newDate.toString()); // 2021-02-01
+```
+
+You can also use {{jsxref("Temporal/PlainDate/add", "add()")}} or {{jsxref("Temporal/PlainDate/subtract", "subtract()")}} to move a certain number of months from the current date.
+
+```js
+const date = Temporal.PlainDate.from("2021-07-01");
+const newDate = date.add({ months: 3 });
+console.log(newDate.toString()); // 2021-10-01
+```
+
+By default, `with()` constrains the day to the range of valid values. Both of the following will set the month to the last month of the year:
+
+```js
+const date = Temporal.PlainDate.from("2021-07-01");
+const lastMonth = date.with({ month: date.monthsInYear }); // 2021-12-01
+const lastMonth2 = date.with({ month: Number.MAX_VALUE }); // 2021-12-01
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal/PlainDate/with", "Temporal.PlainDate.prototype.with()")}}
+- {{jsxref("Temporal/PlainDate/add", "Temporal.PlainDate.prototype.add()")}}
+- {{jsxref("Temporal/PlainDate/subtract", "Temporal.PlainDate.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainDate/year", "Temporal.PlainDate.prototype.year")}}
+- {{jsxref("Temporal/PlainDate/day", "Temporal.PlainDate.prototype.day")}}
+- {{jsxref("Temporal/PlainDate/monthCode", "Temporal.PlainDate.prototype.monthCode")}}
+- {{jsxref("Temporal/PlainDate/daysInMonth", "Temporal.PlainDate.prototype.daysInMonth")}}
+- {{jsxref("Temporal/PlainDate/monthsInYear", "Temporal.PlainDate.prototype.monthsInYear")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/monthcode/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/monthcode/index.md
new file mode 100644
index 000000000000000..89b9a5e154eb71b
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/monthcode/index.md
@@ -0,0 +1,122 @@
+---
+title: Temporal.PlainDate.prototype.monthCode
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate/monthCode
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDate.monthCode
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`monthCode`** accessor property of {{jsxref("Temporal.PlainDate")}} instances returns a calendar-specific string representing the month of this date. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+Usually it is `M` plus a two-digit month number. For leap months, it is the previous month's code followed by `L` (even if it's conceptually a derivative of the following month; for example, in the Hebrew calendar, Adar I has code `M05L` but Adar II has code `M06`). If the leap month is the first month of the year, the code is `M00L`.
+
+> [!NOTE]
+> Don't assume that `monthCode` is a user-friendly string; use `toLocaleString()` to format your date instead. Generally, don't cache the name of months in an array or object. Even though `monthCode` usually maps to the month's name within one calendar, we recommend always computing the month's name using, for example, `date.toLocaleString("en-US", { calendar: date.calendarId, month: "long" })`.
+
+The set accessor of `monthCode` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/PlainDate/with", "with()")}} method to create a new `Temporal.PlainDate` object with the desired new value.
+
+## Examples
+
+### Using monthCode
+
+```js
+const date = Temporal.PlainDate.from("2021-07-01"); // ISO 8601 calendar
+console.log(date.monthCode); // "M07"
+console.log(date.month); // 7
+
+const date2 = Temporal.PlainDate.from("2021-05-01[u-ca=chinese]");
+console.log(date2.monthCode); // "M03"
+console.log(date2.month); // 3; it is March 20 in the Chinese calendar
+
+const date3 = Temporal.PlainDate.from("2023-05-01[u-ca=chinese]");
+console.log(date3.monthCode); // "M03"
+console.log(date3.month); // 4, although it is also March (M03)!
+
+const date4 = Temporal.PlainDate.from("2023-04-01[u-ca=chinese]");
+console.log(date4.monthCode); // "M02L"
+console.log(date4.month); // 3, this month is a leap month, i.e. a duplicate February
+```
+
+### Changing monthCode
+
+```js
+const date = Temporal.PlainDate.from("2021-07-01");
+const newDate = date.with({ month: 2 });
+console.log(newDate.toString()); // 2021-02-01
+```
+
+You can also use {{jsxref("Temporal/PlainDate/add", "add()")}} or {{jsxref("Temporal/PlainDate/subtract", "subtract()")}} to move a certain number of months from the current date.
+
+```js
+const date = Temporal.PlainDate.from("2021-07-01");
+const newDate = date.add({ months: 3 });
+console.log(newDate.toString()); // 2021-10-01
+```
+
+By default, `with()` constrains the day to the range of valid values. Both of the following will set the month to the last month of the year:
+
+```js
+const date = Temporal.PlainDate.from("2021-07-01");
+const lastMonth = date.with({ month: date.monthsInYear }); // 2021-12-01
+const lastMonth2 = date.with({ month: Number.MAX_VALUE }); // 2021-12-01
+```
+
+### Formatting month names
+
+Don't do this:
+
+<!-- prettier-ignore -->
+```js example-bad
+const names = [
+  "January", "February", "March", "April", "May", "June",
+  "July", "August", "September", "October", "November", "December"
+];
+
+const date = Temporal.PlainDate.from("2021-07-01");
+console.log(names[date.month - 1]); // July
+```
+
+Also don't do this:
+
+<!-- prettier-ignore -->
+```js example-bad
+const names = {
+  "M01": "January", "M02": "February", "M03": "March", "M04": "April",
+  "M05": "May", "M06": "June", "M07": "July", "M08": "August",
+  "M09": "September", "M10": "October", "M11": "November", "M12": "December"
+};
+
+const date = Temporal.PlainDate.from("2021-07-01");
+console.log(names[date.monthCode]); // July
+```
+
+Instead, always do this, which is more user-friendly and less error-prone, and easily generalizes to other calendars:
+
+```js
+const date = Temporal.PlainDate.from("2021-07-01");
+console.log(
+  date.toLocaleString("en-US", { calendar: date.calendarId, month: "long" }),
+); // July
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal/PlainDate/with", "Temporal.PlainDate.prototype.with()")}}
+- {{jsxref("Temporal/PlainDate/add", "Temporal.PlainDate.prototype.add()")}}
+- {{jsxref("Temporal/PlainDate/subtract", "Temporal.PlainDate.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainDate/year", "Temporal.PlainDate.prototype.year")}}
+- {{jsxref("Temporal/PlainDate/month", "Temporal.PlainDate.prototype.month")}}
+- {{jsxref("Temporal/PlainDate/daysInMonth", "Temporal.PlainDate.prototype.daysInMonth")}}
+- {{jsxref("Temporal/PlainDate/monthsInYear", "Temporal.PlainDate.prototype.monthsInYear")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/monthsinyear/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/monthsinyear/index.md
new file mode 100644
index 000000000000000..29c06cbb4ca088b
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/monthsinyear/index.md
@@ -0,0 +1,60 @@
+---
+title: Temporal.PlainDate.prototype.monthsInYear
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate/monthsInYear
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDate.monthsInYear
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`monthsInYear`** accessor property of {{jsxref("Temporal.PlainDate")}} instances returns a positive integer representing the number of months in the year of this date. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+For the ISO 8601 calendar, this is always 12, but in other calendar systems it may differ. For example, in calendars using leap months, leap years will have one more month than common years.
+
+The set accessor of `monthsInYear` is `undefined`. You cannot change this property directly.
+
+## Examples
+
+### Using monthsInYear
+
+```js
+const date = Temporal.PlainDate.from("2021-07-01");
+console.log(date.monthsInYear); // 12
+
+const date2 = Temporal.PlainDate.from("2021-07-01[u-ca=chinese]");
+console.log(date2.monthsInYear); // 12
+
+const date3 = Temporal.PlainDate.from("2023-07-01[u-ca=chinese]");
+console.log(date3.monthsInYear); // 13; 2023 is a Chinese leap year
+```
+
+### Changing to the second last month of the year
+
+You can use `monthsInYear` to change to the second last day of the month:
+
+```js
+const date = Temporal.PlainDate.from("2021-07-01");
+const secondLastMonth = date.with({ month: date.monthsInYear - 1 });
+console.log(secondLastMonth.toString()); // 2021-11-01
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal/PlainDate/with", "Temporal.PlainDate.prototype.with()")}}
+- {{jsxref("Temporal/PlainDate/add", "Temporal.PlainDate.prototype.add()")}}
+- {{jsxref("Temporal/PlainDate/subtract", "Temporal.PlainDate.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainDate/year", "Temporal.PlainDate.prototype.year")}}
+- {{jsxref("Temporal/PlainDate/month", "Temporal.PlainDate.prototype.month")}}
+- {{jsxref("Temporal/PlainDate/monthCode", "Temporal.PlainDate.prototype.monthCode")}}
+- {{jsxref("Temporal/PlainDate/daysInMonth", "Temporal.PlainDate.prototype.daysInMonth")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/plaindate/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/plaindate/index.md
new file mode 100644
index 000000000000000..14bb034855f4363
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/plaindate/index.md
@@ -0,0 +1,79 @@
+---
+title: Temporal.PlainDate()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate/PlainDate
+page-type: javascript-constructor
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDate.PlainDate
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.PlainDate()`** constructor creates {{jsxref("Temporal.PlainDate")}} objects.
+
+This constructor allows you to create instances by directly supplying the underlying data. Like all other `Temporal` classes, you should usually construct `Temporal.PlainDate` objects using the {{jsxref("Temporal/PlainDate/from", "Temporal.PlainDate.from()")}} static method, which can handle a variety of input types.
+
+## Syntax
+
+```js-nolint
+new Temporal.PlainDate(year, month, day)
+new Temporal.PlainDate(year, month, day, calendar)
+```
+
+> **Note:** `Temporal.PlainDate()` can only be constructed with [`new`](/en-US/docs/Web/JavaScript/Reference/Operators/new). Attempting to call it without `new` throws a {{jsxref("TypeError")}}.
+
+### Parameters
+
+- `year`
+  - : A number, truncated to an integer, representing the year in the ISO calendar system.
+- `month`
+  - : A number, truncated to an integer, representing the month in the ISO calendar system.
+- `day`
+  - : A number, truncated to an integer, representing the day of the month in the ISO calendar system.
+- `calendar` {{optional_inline}}
+  - : A string representing the [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars) to use. Note that irrespective of the `calendar`, the `year`, `month`, and `day` must be in the ISO 8601 calendar system. Defaults to `"iso8601"`.
+
+### Return value
+
+A new `Temporal.PlainDate` object, representing the date specified by `year`, `month`, `day` (in the ISO calendar), interpreted in the calendar system specified by `calendar`.
+
+### Exceptions
+
+- {{jsxref("TypeError")}}
+  - : Thrown if `calendar` is not a string or `undefined`.
+- {{jsxref("RangeError")}}
+  - : Thrown in one of the following cases:
+    - `year`, `month`, or `day` is not a finite number, or do not represent a valid date in the ISO calendar system.
+    - `calendar` is not a valid calendar identifier.
+
+## Examples
+
+### Using Temporal.PlainDate()
+
+```js
+const plainDate = new Temporal.PlainDate(2021, 7, 1);
+console.log(plainDate.toString()); // 2021-07-01
+
+// Note that the date is stored internally as ISO 8601, even when it's
+// interpreted in a different calendar system. For example, even though
+// 2021-07-01 is 4658-05-22 in the Chinese calendar, you still pass the
+// ISO date to the constructor.
+const plainDate2 = new Temporal.PlainDate(2021, 7, 1, "chinese");
+console.log(plainDate2.toString()); // 2021-07-01[u-ca=chinese]
+console.log(plainDate2.year); // 4658
+console.log(plainDate2.month); // 5
+console.log(plainDate2.day); // 22
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal/PlainDate/from", "Temporal.PlainDate.from()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/since/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/since/index.md
new file mode 100644
index 000000000000000..214dec5b1f90318
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/since/index.md
@@ -0,0 +1,105 @@
+---
+title: Temporal.PlainDate.prototype.since()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate/since
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDate.since
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`since()`** method of {{jsxref("Temporal.PlainDate")}} instances returns a new {{jsxref("Temporal.Duration")}} object representing the duration from another date (in a form convertible by {{jsxref("Temporal/PlainDate/from", "Temporal.PlainDate.from()")}}) to this date. The duration is positive if the other date is before this date, and negative if after.
+
+This method does `this - other`. To do `other - this`, use the {{jsxref("Temporal/PlainDate/until", "until()")}} method.
+
+## Syntax
+
+```js-nolint
+since(other)
+since(other, options)
+```
+
+### Parameters
+
+- `other`
+  - : A string, an object, or a {{jsxref("Temporal.PlainDate")}} instance representing a date to subtract from this date. It is converted to a `Temporal.PlainDate` object using the same algorithm as {{jsxref("Temporal/PlainDate/from", "Temporal.PlainDate.from()")}}. It must have the same calendar as `this`.
+- `options` {{optional_inline}}
+  - : An object containing the options for {{jsxref("Temporal/Duration/round", "Temporal.Duration.prototype.round()")}}, which includes `largestUnit`, `roundingIncrement`, `roundingMode`, and `smallestUnit`. `largestUnit` and `smallestUnit` only accept the units: `"year"`, `"month"`, `"week"`, `"day"`, or their plural forms. For `largestUnit`, the default value `"auto"` means `"day"` or `smallestUnit`, whichever is greater. For `smallestUnit`, the default value is `"day"`. The current date is used as the `relativeTo` option. Note that using [units larger than `"day"`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#calendar_durations) may make the duration not portable to other calendars or dates.
+
+### Return value
+
+A new {{jsxref("Temporal.Duration")}} object representing the duration _since_ `other` to this date. The duration is positive if `other` is before this date, and negative if after.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown in one of the following cases:
+    - `other` has a different calendar than `this`.
+    - Any of the options is invalid.
+
+## Examples
+
+### Using since()
+
+```js
+const date = Temporal.PlainDate.from("2022-12-25");
+const now = Temporal.Now.plainDateISO();
+const duration = now.since(date);
+const formatter = new Intl.DurationFormat("en-US", { style: "long" });
+console.log(`It's been ${formatter.format(duration)} since that Christmas...`);
+// Expected output: "It's been [number] days since that Christmas..."
+
+const duration2 = now.since(date, { smallestUnit: "month" });
+console.log(`It's been ${formatter.format(duration2)} since that Christmas...`);
+// Expected output: "It's been [number] months since that Christmas..."
+
+const duration3 = now.since(date, {
+  largestUnit: "year",
+  smallestUnit: "month",
+});
+console.log(`It's been ${formatter.format(duration3)} since that Christmas...`);
+// Expected output: "It's been [number] years, [number] months since that Christmas..."
+```
+
+### Rounding the result
+
+By default the fractional part of the `smallestUnit` is truncated. You can round it up using the `roundingIncrement` and `roundingMode` options.
+
+```js
+const date1 = Temporal.PlainDate.from("2022-01-01");
+const date2 = Temporal.PlainDate.from("2022-01-28");
+const duration = date2.since(date1, {
+  smallestUnit: "day",
+  roundingIncrement: 5,
+  roundingMode: "ceil",
+});
+console.log(duration.toString()); // "P30D"
+```
+
+### Comparing different calendars
+
+By default, the two dates must have the same calendar. This is to avoid ambiguity in the meaning of months and years. If you want to compare dates from different calendars, you can convert them to the same calendar first.
+
+```js
+const date1 = Temporal.PlainDate.from("2022-01-01");
+const date2 = Temporal.PlainDate.from("2022-01-28[u-ca=chinese]");
+const duration = date2.withCalendar("iso8601").since(date1);
+console.log(duration.toString()); // "P27D"
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/PlainDate/add", "Temporal.PlainDate.prototype.add()")}}
+- {{jsxref("Temporal/PlainDate/subtract", "Temporal.PlainDate.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainDate/until", "Temporal.PlainDate.prototype.until()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/subtract/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/subtract/index.md
new file mode 100644
index 000000000000000..ac001831c0175bc
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/subtract/index.md
@@ -0,0 +1,70 @@
+---
+title: Temporal.PlainDate.prototype.subtract()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate/subtract
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDate.subtract
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`subtract()`** method of {{jsxref("Temporal.PlainDate")}} instances returns a new `Temporal.PlainDate` object representing this date moved backward by a given duration (in a form convertible by {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}).
+
+If you want to subtract two dates and get a duration, use {{jsxref("Temporal/PlainDate/since", "since()")}} or {{jsxref("Temporal/PlainDate/until", "until()")}} instead.
+
+## Syntax
+
+```js-nolint
+subtract(duration)
+subtract(duration, options)
+```
+
+### Parameters
+
+- `duration`
+  - : A string, an object, or a {{jsxref("Temporal.Duration")}} instance representing a duration to subtract from this date. It is converted to a `Temporal.Duration` object using the same algorithm as {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}.
+- `options` {{optional_inline}}
+  - : An object containing the following property:
+    - `overflow` {{optional_inline}}
+      - : A string specifying the behavior when a date component is out of range. Possible values are:
+        - `"constrain"` (default)
+          - : The date component is [clamped](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate#invalid_date_clamping) to the valid range.
+        - `"reject"`
+          - : A {{jsxref("RangeError")}} is thrown if the date component is out of range.
+
+### Return value
+
+A new `Temporal.PlainDate` object representing the date specified by the original `PlainDate`, minus the duration.
+
+## Description
+
+Subtracting a duration is equivalent to [adding](Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate/add) its [negation](Web/JavaScript/Reference/Global_Objects/Temporal/Duration/negated), so all the same considerations apply.
+
+## Examples
+
+### Subtracting a duration
+
+```js
+const start = Temporal.PlainDate.from("2022-01-01");
+const end = start.subtract({ years: 1, months: 2, weeks: 3, days: 4 });
+console.log(end.toString()); // 2020-10-07
+```
+
+For more examples, see {{jsxref("Temporal/PlainDate/add", "add()")}}.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/PlainDate/add", "Temporal.PlainDate.prototype.add()")}}
+- {{jsxref("Temporal/PlainDate/since", "Temporal.PlainDate.prototype.since()")}}
+- {{jsxref("Temporal/PlainDate/until", "Temporal.PlainDate.prototype.until()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/tojson/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/tojson/index.md
new file mode 100644
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--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/tojson/index.md
@@ -0,0 +1,70 @@
+---
+title: Temporal.PlainDate.prototype.toJSON()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate/toJSON
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDate.toJSON
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toJSON()`** method of {{jsxref("Temporal.PlainDate")}} instances returns a string representing this date in the same [RFC 9557 format](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate#rfc_9557_format) as calling {{jsxref("Temporal/PlainDate/toString", "toString()")}}. It is intended to be implicitly called by {{jsxref("JSON.stringify()")}}.
+
+## Syntax
+
+```js-nolint
+toJSON()
+```
+
+### Parameters
+
+None.
+
+### Return value
+
+A string representing the given date in the [RFC 9557 format](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate#rfc_9557_format), with the calendar annotation included if it is not `"iso8601"`.
+
+## Description
+
+The `toJSON()` method is automatically called by {{jsxref("JSON.stringify()")}} when a `Temporal.PlainDate` object is stringified. This method is generally intended to, by default, usefully serialize `Temporal.PlainDate` objects during [JSON](/en-US/docs/Glossary/JSON) serialization, which can then be deserialized using the {{jsxref("Temporal/PlainDate/from", "Temporal.PlainDate.from()")}} function as the reviver of {{jsxref("JSON.parse()")}}.
+
+## Examples
+
+### Using toJSON()
+
+```js
+const date = Temporal.PlainDate.from({ year: 2021, month: 8, day: 1 });
+const dateStr = date.toJSON(); // '2021-08-01'
+const d2 = Temporal.PlainDate.from(dateStr);
+```
+
+### JSON serialization and parsing
+
+This example shows how `Temporal.PlainDate` can be serialized as JSON without extra effort, and how to parse it back.
+
+```js
+const date = Temporal.PlainDate.from({ year: 2021, month: 8, day: 1 });
+const jsonStr = JSON.stringify({ date }); // '{"date":"2021-08-01"}'
+const obj = JSON.parse(jsonStr, (key, value) => {
+  if (key === "date") {
+    return Temporal.PlainDate.from(value);
+  }
+  return value;
+});
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal/PlainDate/from", "Temporal.PlainDate.from()")}}
+- {{jsxref("Temporal/PlainDate/toString", "Temporal.PlainDate.prototype.toString()")}}
+- {{jsxref("Temporal/PlainDate/toLocaleString", "Temporal.PlainDate.prototype.toLocaleString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/tolocalestring/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/tolocalestring/index.md
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--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/tolocalestring/index.md
@@ -0,0 +1,106 @@
+---
+title: Temporal.PlainDate.prototype.toLocaleString()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate/toLocaleString
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDate.toLocaleString
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toLocaleString()`** method of {{jsxref("Temporal.PlainDate")}} instances returns a string with a language-sensitive representation of this date. In implementations with [`Intl.DateTimeFormat` API](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat) support, this method delegates to `Intl.DateTimeFormat`.
+
+Every time `toLocaleString` is called, it has to perform a search in a big database of localization strings, which is potentially inefficient. When the method is called many times with the same arguments, it is better to create a {{jsxref("Intl.DateTimeFormat")}} object and use its {{jsxref("Intl/DateTimeFormat/format", "format()")}} method, because a `DateTimeFormat` object remembers the arguments passed to it and may decide to cache a slice of the database, so future `format` calls can search for localization strings within a more constrained context.
+
+## Syntax
+
+```js-nolint
+toLocaleString()
+toLocaleString(locales)
+toLocaleString(locales, options)
+```
+
+### Parameters
+
+The `locales` and `options` parameters customize the behavior of the function and let applications specify the language whose formatting conventions should be used.
+
+In implementations that support the [`Intl.DateTimeFormat` API](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat), these parameters correspond exactly to the [`Intl.DateTimeFormat()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat/DateTimeFormat) constructor's parameters. Implementations without `Intl.DateTimeFormat` support return the exact same string as {{jsxref("Temporal/PlainDate/toString", "toString()")}}, ignoring both parameters.
+
+- `locales` {{optional_inline}}
+  - : A string with a BCP 47 language tag, or an array of such strings. Corresponds to the [`locales`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat/DateTimeFormat#locales) parameter of the `Intl.DateTimeFormat()` constructor.
+- `options` {{optional_inline}}
+
+  - : An object adjusting the output format. Corresponds to the [`options`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat/DateTimeFormat#options) parameter of the `Intl.DateTimeFormat()` constructor. If this date's calendar is not `"iso8601"`, the `calendar` option must be provided with the same value; otherwise, if this date's calendar is `"iso8601"`, the `calendar` option can be any value. Regarding the [date-time component options](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat/DateTimeFormat#date-time_component_options) and the style shortcuts (`dateStyle` and `timeStyle`), the options should follow one of these forms:
+
+    - Provide none of them: `year`, `month`, and `day` will default to `"numeric"`.
+    - Provide `dateStyle` only: it expands to `weekday`, `era`, `year`, `month`, and `day` formats.
+    - Provide some date-time component options, where at least one of them is a date option (`weekday`, `year`, `month`, `day`). Only the specified date components will be included in the output.
+
+See the [`Intl.DateTimeFormat()` constructor](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat/DateTimeFormat) for details on these parameters and how to use them.
+
+### Return value
+
+A string representing the given date according to language-specific conventions.
+
+In implementations with `Intl.DateTimeFormat`, this is equivalent to `new Intl.DateTimeFormat(locales, options).format(date)`, where `options` has been normalized as described above.
+
+> [!NOTE]
+> Most of the time, the formatting returned by `toLocaleString()` is consistent. However, the output may vary between implementations, even within the same locale — output variations are by design and allowed by the specification. It may also not be what you expect. For example, the string may use non-breaking spaces or be surrounded by bidirectional control characters. You should not compare the results of `toLocaleString()` to hardcoded constants.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown if any of the options is invalid.
+- {{jsxref("TypeError")}}
+  - : Thrown if any of the options is not of the expected type.
+
+## Examples
+
+### Using toLocaleString()
+
+Basic use of this method without specifying a `locale` returns a formatted string in the default locale and with default options.
+
+```js
+const date = Temporal.PlainDate.from("2021-08-01");
+
+console.log(date.toLocaleString()); // 8/1/2021 (assuming en-US locale)
+```
+
+If the date's calendar doesn't match the locale's default calendar, and the date's calendar is not `iso8601`, an explicit `calendar` option must be provided with the same value.
+
+```js
+const date = Temporal.PlainDate.from("2021-08-01[u-ca=japanese]");
+// The ja-JP locale uses the Gregorian calendar by default
+date.toLocaleString("ja-JP", { calendar: "japanese" }); // R3/8/1
+```
+
+### Using toLocaleString() with options
+
+You can customize which parts of the date are included in the output by providing the `options` parameter.
+
+```js
+const date = Temporal.PlainDate.from("2021-08-01");
+date.toLocaleString("en-US", { dateStyle: "full" }); // Sunday, August 1, 2021
+date.toLocaleString("en-US", {
+  year: "numeric",
+  month: "long",
+  day: "numeric",
+}); // August 1, 2021
+date.toLocaleString("en-US", { year: "numeric", month: "long" }); // August 2021
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Intl.DateTimeFormat")}}
+- {{jsxref("Temporal/PlainDate/toJSON", "Temporal.PlainDate.prototype.toJSON()")}}
+- {{jsxref("Temporal/PlainDate/toString", "Temporal.PlainDate.prototype.toString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/toplaindatetime/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/toplaindatetime/index.md
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+---
+title: Temporal.PlainDate.prototype.toPlainDateTime()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate/toPlainDateTime
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDate.toPlainDateTime
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toPlainDateTime()`** method of {{jsxref("Temporal.PlainDate")}} instances returns a new {{jsxref("Temporal.PlainDateTime")}} object representing this date and a supplied time in the same calendar system.
+
+## Syntax
+
+```js-nolint
+toPlainDateTime()
+toPlainDateTime(plainTime)
+```
+
+### Parameters
+
+- `plainTime` {{optional_inline}}
+  - : A string, an object, or a {{jsxref("Temporal.PlainTime")}} instance representing the time component of the resulting `PlainDateTime`. It is converted to a `Temporal.PlainTime` object using the same algorithm as {{jsxref("Temporal/PlainTime/from", "Temporal.PlainTime.from()")}}. Defaults to `"00:00:00"`.
+
+### Return value
+
+A new `Temporal.PlainDateTime` object representing the date and time specified by this date and `plainTime`, interpreted in the calendar system of this date.
+
+## Examples
+
+### Using toPlainDateTime()
+
+```js
+const date = Temporal.PlainDate.from("2021-07-01");
+const dateTime = date.toPlainDateTime("12:34:56");
+console.log(dateTime.toString()); // 2021-07-01T12:34:56
+
+const midnight = date.toPlainDateTime();
+console.log(midnight.toString()); // 2021-07-01T00:00:00
+
+const date2 = Temporal.PlainDate.from("2021-07-01[u-ca=chinese]");
+const dateTime2 = date2.toPlainDateTime("12:34:56");
+console.log(dateTime2.toString()); // 2021-07-01T12:34:56[u-ca=chinese]
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal.PlainTime")}}
+- {{jsxref("Temporal/PlainDate/toPlainMonthDay", "Temporal.PlainDate.prototype.toPlainMonthDay()")}}
+- {{jsxref("Temporal/PlainDate/toPlainYearMonth", "Temporal.PlainDate.prototype.toPlainYearMonth()")}}
+- {{jsxref("Temporal/PlainDate/toZonedDateTime", "Temporal.PlainDate.prototype.toZonedDateTime()")}}
+- {{jsxref("Temporal/PlainDateTime/toPlainDate", "Temporal.PlainDateTime.prototype.toPlainDate()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/toplainmonthday/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/toplainmonthday/index.md
new file mode 100644
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+---
+title: Temporal.PlainDate.prototype.toPlainMonthDay()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate/toPlainMonthDay
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDate.toPlainMonthDay
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toPlainMonthDay()`** method of {{jsxref("Temporal.PlainDate")}} instances returns a new {{jsxref("Temporal.PlainMonthDay")}} object representing the {{jsxref("Temporal/PlainDate/monthCode", "monthCode")}} and {{jsxref("Temporal/PlainDate/day", "day")}} of this date in the same calendar system.
+
+Note that `PlainMonthDay` objects do not have a `month` component, because months with the same name can have different `month` indexes in different years due to leap months.
+
+## Syntax
+
+```js-nolint
+toPlainMonthDay()
+```
+
+### Parameters
+
+None.
+
+### Return value
+
+A new `Temporal.PlainMonthDay` object representing the {{jsxref("Temporal/PlainDate/monthCode", "monthCode")}} and {{jsxref("Temporal/PlainDate/day", "day")}} of this date in the same calendar system.
+
+## Examples
+
+### Using toPlainMonthDay()
+
+```js
+const date = Temporal.PlainDate.from("2021-07-01");
+const monthDay = date.toPlainMonthDay();
+console.log(monthDay.toString()); // 07-01
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal.PlainMonthDay")}}
+- {{jsxref("Temporal/PlainDate/toPlainDateTime", "Temporal.PlainDate.prototype.toPlainDateTime()")}}
+- {{jsxref("Temporal/PlainDate/toPlainYearMonth", "Temporal.PlainDate.prototype.toPlainYearMonth()")}}
+- {{jsxref("Temporal/PlainDate/toZonedDateTime", "Temporal.PlainDate.prototype.toZonedDateTime()")}}
+- {{jsxref("Temporal/PlainMonthDay/toPlainDate", "Temporal.PlainMonthDay.prototype.toPlainDate()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/toplainyearmonth/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/toplainyearmonth/index.md
new file mode 100644
index 000000000000000..d049056c74a0208
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/toplainyearmonth/index.md
@@ -0,0 +1,53 @@
+---
+title: Temporal.PlainDate.prototype.toPlainYearMonth()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate/toPlainYearMonth
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDate.toPlainYearMonth
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toPlainYearMonth()`** method of {{jsxref("Temporal.PlainDate")}} instances returns a new {{jsxref("Temporal.PlainYearMonth")}} object representing the {{jsxref("Temporal/PlainDate/year", "year")}} and {{jsxref("Temporal/PlainDate/month", "month")}} of this date in the same calendar system.
+
+## Syntax
+
+```js-nolint
+toPlainYearMonth()
+```
+
+### Parameters
+
+None.
+
+### Return value
+
+A new `Temporal.PlainYearMonth` object representing the {{jsxref("Temporal/PlainDate/year", "year")}} and {{jsxref("Temporal/PlainDate/month", "month")}} of this date in the same calendar system.
+
+## Examples
+
+### Using toPlainYearMonth()
+
+```js
+const date = Temporal.PlainDate.from("2021-07-01");
+const yearMonth = date.toPlainYearMonth();
+console.log(yearMonth.toString()); // 2021-07
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal.PlainYearMonth")}}
+- {{jsxref("Temporal/PlainDate/toPlainDateTime", "Temporal.PlainDate.prototype.toPlainDateTime()")}}
+- {{jsxref("Temporal/PlainDate/toPlainMonthDay", "Temporal.PlainDate.prototype.toPlainMonthDay()")}}
+- {{jsxref("Temporal/PlainDate/toZonedDateTime", "Temporal.PlainDate.prototype.toZonedDateTime()")}}
+- {{jsxref("Temporal/PlainYearMonth/toPlainDate", "Temporal.PlainYearMonth.prototype.toPlainDate()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/tostring/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/tostring/index.md
new file mode 100644
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--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/tostring/index.md
@@ -0,0 +1,88 @@
+---
+title: Temporal.PlainDate.prototype.toString()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate/toString
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDate.toString
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toString()`** method of {{jsxref("Temporal.PlainDate")}} instances returns a string representing this date in the [RFC 9557 format](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate#rfc_9557_format).
+
+## Syntax
+
+```js-nolint
+toString()
+toString(options)
+```
+
+### Parameters
+
+- `options` {{optional_inline}}
+  - : An object containing the following property:
+    - `calendarName` {{optional_inline}}
+      - : Whether to show the calendar annotation (`[u-ca=calendar_id]`) in the return value. Possible values are:
+        - `"auto"` (default)
+          - : Include the calendar annotation if the calendar is not `"iso8601"`.
+        - `"always"`
+          - : Always include the calendar annotation.
+        - `"never"`
+          - : Never include the calendar annotation. This makes the returned string not recoverable to the same {{jsxref("Temporal.PlainDate")}} instance, although the date value still remains the same.
+        - `"critical"`
+          - : Always include the calendar annotation, and add a critical flag: `[!u-ca=calendar_id]`. Useful when sending the string to certain systems, but not useful for Temporal itself.
+
+### Return value
+
+A string in the [RFC 9557 format](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate#rfc_9557_format) representing this date. The calendar annotation is included as specified.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown if any of the options is invalid.
+- {{jsxref("TypeError")}}
+  - : Thrown if `options` is not an object or `undefined`.
+
+## Examples
+
+### Using toString()
+
+```js
+const date = Temporal.PlainDate.from("2021-08-01");
+console.log(date.toString()); // '2021-08-01'
+```
+
+### Using options
+
+```js
+const isoDate = Temporal.PlainDate.from({ year: 2021, month: 8, day: 1 });
+const date = Temporal.PlainDate.from({
+  year: 2021,
+  month: 8,
+  day: 1,
+  calendar: "islamic",
+});
+console.log(isoDate.toString({ calendarName: "auto" })); // '2021-08-01'
+console.log(date.toString({ calendarName: "auto" })); // '2582-12-18[u-ca=islamic]'
+console.log(isoDate.toString({ calendarName: "always" })); // '2021-08-01[u-ca=iso8601]'
+console.log(date.toString({ calendarName: "always" })); // '2582-12-18[u-ca=islamic]'
+console.log(date.toString({ calendarName: "never" })); // '2582-12-18'
+console.log(isoDate.toString({ calendarName: "critical" })); // '2021-08-01[!u-ca=iso8601]'
+console.log(date.toString({ calendarName: "critical" })); // '2582-12-18[!u-ca=islamic]'
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal/PlainDate/from", "Temporal.PlainDate.from()")}}
+- {{jsxref("Temporal/PlainDate/toJSON", "Temporal.PlainDate.prototype.toJSON()")}}
+- {{jsxref("Temporal/PlainDate/toLocaleString", "Temporal.PlainDate.prototype.toLocaleString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/tozoneddatetime/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/tozoneddatetime/index.md
new file mode 100644
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--- /dev/null
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@@ -0,0 +1,88 @@
+---
+title: Temporal.PlainDate.prototype.toZonedDateTime()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate/toZonedDateTime
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDate.toZonedDateTime
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toZonedDateTime()`** method of {{jsxref("Temporal.PlainDate")}} instances returns a new {{jsxref("Temporal.ZonedDateTime")}} object representing this date, a supplied time, and a supplied time zone, in the same calendar system.
+
+## Syntax
+
+```js-nolint
+toZonedDateTime(timeZone)
+toZonedDateTime(info)
+```
+
+### Parameters
+
+- `timeZone`
+  - : Either a string or a {{jsxref("Temporal.ZonedDateTime")}} instance representing the [`timeZone`](#timezone_2) option. This is a convenience overload, so `toZonedDateTime(timeZone)` is equivalent to `toZonedDateTime({ timeZone })`, where `timeZone` is a string or {{jsxref("Temporal.ZonedDateTime")}}. This overload is chosen when the first argument is not an object, or the object's `timeZone` property is `undefined` (because `ZonedDateTime` instances have a {{jsxref("Temporal/ZonedDateTime/timeZoneId", "timeZoneId")}} property instead).
+- `info`
+  - : An object containing some or all of the following properties (in the order they are retrieved and validated):
+    - `plainTime` {{optional_inline}}
+      - : A string, an object, or a {{jsxref("Temporal.PlainTime")}} instance representing the time component of the resulting `ZonedDateTime`. It is converted to a `Temporal.PlainTime` object using the same algorithm as {{jsxref("Temporal/PlainTime/from", "Temporal.PlainTime.from()")}}. Defaults to the first valid time in this time zone on this calendar date, which is usually `"00:00:00"`, but may be different if, for example, daylight saving time skips midnight.
+    - `timeZone`
+      - : Either a string or a {{jsxref("Temporal.ZonedDateTime")}} instance representing the time zone to use. If a `Temporal.ZonedDateTime` instance, its time zone is used. If a string, it can be a named time zone identifier, an offset time zone identifier, or a date-time string containing a time zone identifier or an offset (see [time zones and offsets](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#time_zones_and_offsets) for more information).
+
+### Return value
+
+A new `Temporal.ZonedDateTime` object representing the date and time specified by this date, `plainTime`, and `timeZone`, interpreted in the calendar system of this date.
+
+In the case of [ambiguities](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#ambiguity_and_gaps_from_local_time_to_utc_time), the `compatible` behavior is always used: if the time falls into a gap, we move forward by the gap length; if the time falls into an ambiguity, we choose the earlier of the two possibilities. This means the resulting `ZonedDateTime` may have a potentially different date or time than the input.
+
+### Exceptions
+
+- {{jsxref("TypeError")}}
+  - : Thrown if `timeZone` is not a string or a `Temporal.ZonedDateTime` instance.
+- {{jsxref("RangeError")}}
+  - : Thrown if `timeZone` is a string that is not a valid time zone identifier.
+
+## Examples
+
+### Using toZonedDateTime()
+
+```js
+const summer = Temporal.PlainDate.from("2021-07-01");
+// Just time zone
+const summerTime = summer.toZonedDateTime("America/New_York");
+console.log(summerTime.toString()); // 2021-07-01T00:00:00-04:00[America/New_York]
+
+const winter = Temporal.PlainDate.from("2021-01-01");
+// Time zone and time
+const winterTime = winter.toZonedDateTime({
+  plainTime: "12:34:56",
+  timeZone: "America/New_York",
+});
+console.log(winterTime.toString()); // 2021-01-01T12:34:56-05:00[America/New_York]
+
+const spring = Temporal.PlainDate.from("2021-03-01");
+// Time zone as object and time as object
+const springTime = spring.toZonedDateTime({
+  plainTime: summerTime.toPlainTime(),
+  timeZone: winterTime,
+});
+console.log(springTime.toString()); // 2021-03-01T00:00:00-05:00[America/New_York]
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal.PlainTime")}}
+- {{jsxref("Temporal/PlainDate/toPlainDateTime", "Temporal.PlainDate.prototype.toPlainDateTime()")}}
+- {{jsxref("Temporal/PlainDate/toPlainMonthDay", "Temporal.PlainDate.prototype.toPlainMonthDay()")}}
+- {{jsxref("Temporal/PlainDate/toPlainYearMonth", "Temporal.PlainDate.prototype.toPlainYearMonth()")}}
+- {{jsxref("Temporal/ZonedDateTime/toPlainDate", "Temporal.ZonedDateTime.prototype.toPlainDate()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/until/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/until/index.md
new file mode 100644
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--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/until/index.md
@@ -0,0 +1,68 @@
+---
+title: Temporal.PlainDate.prototype.until()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate/until
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDate.until
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`until()`** method of {{jsxref("Temporal.PlainDate")}} instances returns a new {{jsxref("Temporal.Duration")}} object representing the duration from this date to another date (in a form convertible by {{jsxref("Temporal/PlainDate/from", "Temporal.PlainDate.from()")}}). The duration is positive if the other date is after this date, and negative if before.
+
+This method does `other - this`. To do `this - other`, use the {{jsxref("Temporal/PlainDate/since", "since()")}} method.
+
+## Syntax
+
+```js-nolint
+until(other)
+until(other, options)
+```
+
+### Parameters
+
+- `other`
+  - : A string, an object, or a {{jsxref("Temporal.PlainDate")}} instance representing a date to subtract this date from. It is converted to a `Temporal.PlainDate` object using the same algorithm as {{jsxref("Temporal/PlainDate/from", "Temporal.PlainDate.from()")}}. It must have the same calendar as `this`.
+- `options` {{optional_inline}}
+  - : The same options as [`since()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate/since#options).
+
+### Return value
+
+A new {{jsxref("Temporal.Duration")}} object representing the duration from this date _until_ `other`. The duration is positive if `other` is after this date, and negative if before.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown in one of the following cases:
+    - `other` has a different calendar than `this`.
+    - Any of the options is invalid.
+
+## Examples
+
+### Using until()
+
+```js
+const launch = Temporal.PlainDate.from("2035-01-01");
+const now = Temporal.Now.plainDateISO();
+const duration = now.until(launch);
+console.log(`It will be ${duration.toLocaleString("en-US")} until the launch`);
+```
+
+For more examples, see [`since()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate/since).
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/PlainDate/add", "Temporal.PlainDate.prototype.add()")}}
+- {{jsxref("Temporal/PlainDate/subtract", "Temporal.PlainDate.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainDate/since", "Temporal.PlainDate.prototype.since()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/valueof/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/valueof/index.md
new file mode 100644
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--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/valueof/index.md
@@ -0,0 +1,66 @@
+---
+title: Temporal.PlainDate.prototype.valueOf()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate/valueOf
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDate.valueOf
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`valueOf()`** method of {{jsxref("Temporal.PlainDate")}} instances throws a {{jsxref("TypeError")}}, which prevents `Temporal.PlainDate` instances from being [implicitly converted to primitives](/en-US/docs/Web/JavaScript/Data_structures#primitive_coercion) when used in arithmetic or comparison operations.
+
+## Syntax
+
+```js-nolint
+valueOf()
+```
+
+### Parameters
+
+None.
+
+### Return value
+
+None.
+
+### Exceptions
+
+- {{jsxref("TypeError")}}
+  - : Always thrown.
+
+## Description
+
+Because both [primitive conversion](/en-US/docs/Web/JavaScript/Data_structures#primitive_coercion) and [number conversion](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number#number_coercion) call `valueOf()` before `toString()`, if `valueOf()` is absent, then an expression like `date1 > date2` would implicitly compare them as strings, which may have unexpected results. By throwing a `TypeError`, `Temporal.PlainDate` instances prevent such implicit conversions. You need to explicitly convert them to strings using {{jsxref("Temporal/PlainDate/toString", "Temporal.PlainDate.prototype.toString()")}}, or use the {{jsxref("Temporal/PlainDate/compare", "Temporal.PlainDate.compare()")}} static method to compare them.
+
+## Examples
+
+### Arithmetic and comparison operations on Temporal.PlainDate
+
+All arithmetic and comparison operations on `Temporal.PlainDate` instances should use the dedicated methods or convert them to primitives explicitly.
+
+```js
+const date1 = Temporal.PlainDate.from("2022-01-01");
+const date2 = Temporal.PlainDate.from("2022-07-01");
+date1 > date2; // TypeError: can't convert PlainDate to primitive type
+Temporal.PlainDate.compare(date1, date2); // -1
+
+date2 - date1; // TypeError: can't convert PlainDate to primitive type
+date2.since(date1).toString(); // "P181D"
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal/PlainDate/toString", "Temporal.PlainDate.prototype.toString()")}}
+- {{jsxref("Temporal/PlainDate/toJSON", "Temporal.PlainDate.prototype.toJSON()")}}
+- {{jsxref("Temporal/PlainDate/toLocaleString", "Temporal.PlainDate.prototype.toLocaleString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/weekofyear/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/weekofyear/index.md
new file mode 100644
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--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/weekofyear/index.md
@@ -0,0 +1,72 @@
+---
+title: Temporal.PlainDate.prototype.weekOfYear
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate/weekOfYear
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDate.weekOfYear
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`weekOfYear`** accessor property of {{jsxref("Temporal.PlainDate")}} instances returns a positive integer representing the 1-based week index in the {{jsxref("Temporal/PlainDate/yearOfWeek", "yearOfWeek")}} of this date, or `undefined` if the calendar does not have a well-defined week system. The first week of the year is `1`. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+Note that for ISO 8601, the first and last few days of the year may be attributed to the last week of the previous year or the first week of the next year. Namely, if a week crosses two years, then it belongs to the year that has the majority of its days. To get the year that the `weekOfYear` belongs to, use the {{jsxref("Temporal/PlainDate/yearOfWeek", "yearOfWeek")}} property, not the {{jsxref("Temporal/PlainDate/year", "year")}} property.
+
+The set accessor of `weekOfYear` is `undefined`. You cannot change this property directly. To create a new `Temporal.PlainDate` object with the desired new `weekOfYear` value, use the {{jsxref("Temporal/PlainDate/add", "add()")}} or {{jsxref("Temporal/PlainDate/subtract", "subtract()")}} method with the appropriate number of `weeks`.
+
+## Examples
+
+### Using weekOfYear
+
+```js
+const date = Temporal.PlainDate.from("2021-07-01");
+console.log(date.weekOfYear); // 26
+
+// If 01-01 is a Friday/Saturday/Sunday, it belongs to the last week of the previous year
+const date2 = Temporal.PlainDate.from("2021-01-01");
+console.log(date2.dayOfWeek); // 5
+console.log(date2.weekOfYear); // 53; 2020 has 53 weeks
+console.log(date2.yearOfWeek); // 2020
+
+// Otherwise, it belongs to the first week of the year
+const date3 = Temporal.PlainDate.from("2020-01-01");
+console.log(date3.dayOfWeek); // 3
+console.log(date3.weekOfYear); // 1
+console.log(date3.yearOfWeek); // 2020
+
+// Similarly, if 12-31 is a Monday/Tuesday/Wednesday, it belongs to the first week of the next year
+const date4 = Temporal.PlainDate.from("2019-12-31");
+console.log(date4.dayOfWeek); // 2
+console.log(date4.weekOfYear); // 1
+console.log(date4.yearOfWeek); // 2020
+```
+
+### Changing weekOfYear
+
+`PlainDate` does not support changing `weekOfYear` directly. To change the week, you need to first figure out the difference in weeks to your desired week, then use `add` or `subtract` to adjust the date accordingly. For example, to change to the previous week:
+
+```js
+const date = Temporal.PlainDate.from("2021-07-01");
+const previousWeek = date.subtract({ weeks: 1 });
+console.log(previousWeek.toString()); // 2021-06-24
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal/PlainDate/with", "Temporal.PlainDate.prototype.with()")}}
+- {{jsxref("Temporal/PlainDate/add", "Temporal.PlainDate.prototype.add()")}}
+- {{jsxref("Temporal/PlainDate/subtract", "Temporal.PlainDate.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainDate/yearOfWeek", "Temporal.PlainDate.prototype.yearOfWeek")}}
+- {{jsxref("Temporal/PlainDate/dayOfWeek", "Temporal.PlainDate.prototype.dayOfWeek")}}
+- {{jsxref("Temporal/PlainDate/daysInWeek", "Temporal.PlainDate.prototype.daysInWeek")}}
+- {{jsxref("Temporal/PlainDate/daysInYear", "Temporal.PlainDate.prototype.daysInYear")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/with/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/with/index.md
new file mode 100644
index 000000000000000..17f51491e6a119f
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/with/index.md
@@ -0,0 +1,80 @@
+---
+title: Temporal.PlainDate.prototype.with()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate/with
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDate.with
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`with()`** method of {{jsxref("Temporal.PlainDate")}} instances returns a new `Temporal.PlainDate` object representing this date with some fields replaced by new values. Because all `Temporal` objects are designed to be immutable, this method essentially functions as the setter for the date's fields.
+
+To replace the {{jsxref("Temporal/PlainDate/calendarId", "calendarId")}} property, use the {{jsxref("Temporal/PlainDate/withCalendar", "withCalendar()")}} method instead.
+
+## Syntax
+
+```js-nolint
+with(info)
+with(info, options)
+```
+
+### Parameters
+
+- `info`
+  - : An object containing at least one of the properties recognized by {{jsxref("Temporal/PlainDate/from", "Temporal.PlainDate.from()")}} (except `calendar`): `day`, `era` and `eraYear`, `month`, `monthCode`, `year`. Unspecified properties use the values from the original date. You only need to provide one of `month` or `monthCode`, and one of `era` and `eraYear` or `year`, and the other will be updated accordingly.
+- `options` {{optional_inline}}
+  - : An object containing the following property:
+    - `overflow` {{optional_inline}}
+      - : A string specifying the behavior when a date component is out of range. Possible values are:
+        - `"constrain"` (default)
+          - : The date component is [clamped](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate#invalid_date_clamping) to the valid range.
+        - `"reject"`
+          - : A {{jsxref("RangeError")}} is thrown if the date component is out of range.
+
+### Return value
+
+A new `Temporal.PlainDate` object, where the fields specified in `info` that are not `undefined` are replaced by the corresponding values, and the rest of the fields are copied from the original date.
+
+### Exceptions
+
+- {{jsxref("TypeError")}}
+  - : Thrown in one of the following cases:
+    - `info` is not an object.
+    - `options` is not an object or `undefined`.
+- {{jsxref("RangeError")}}
+  - : Thrown in one of the following cases:
+    - The provided properties that specify the same component are inconsistent.
+    - The provided non-numerical properties are not valid; for example, if `monthCode` is never a valid month code in this calendar.
+    - The provided numerical properties are out of range, and `options.overflow` is set to `"reject"`.
+
+## Examples
+
+### Using with()
+
+```js
+const date = Temporal.PlainDate.from("2021-07-06");
+const newDate = date.with({ day: date.daysInMonth });
+console.log(newDate.toString()); // 2021-07-31
+const nextDecade = date.with({ year: date.year + 10 });
+console.log(nextDecade.toString()); // 2031-07-06
+```
+
+For more examples, see the documentation for the individual properties that can be set using `with()`.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal/PlainDate/withCalendar", "Temporal.PlainDate.prototype.withCalendar()")}}
+- {{jsxref("Temporal/PlainDate/from", "Temporal.PlainDate.from()")}}
+- {{jsxref("Temporal/PlainDate/add", "Temporal.PlainDate.prototype.add()")}}
+- {{jsxref("Temporal/PlainDate/subtract", "Temporal.PlainDate.prototype.subtract()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/withcalendar/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/withcalendar/index.md
new file mode 100644
index 000000000000000..4df0221b8cb2355
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/withcalendar/index.md
@@ -0,0 +1,62 @@
+---
+title: Temporal.PlainDate.prototype.withCalendar()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate/withCalendar
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDate.withCalendar
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`withCalendar()`** method of {{jsxref("Temporal.PlainDate")}} instances returns a new `Temporal.PlainDate` object representing this date interpreted in the new calendar system. Because all `Temporal` objects are designed to be immutable, this method essentially functions as the setter for the date's {{jsxref("Temporal/PlainDate/calendarId", "calendarId")}} property.
+
+To replace the date component properties, use the {{jsxref("Temporal/PlainDate/with", "with()")}} method instead.
+
+## Syntax
+
+```js-nolint
+withCalendar(calendar)
+```
+
+### Parameters
+
+- `calendar`
+  - : A string that corresponds to the {{jsxref("Temporal/PlainDate/calendarId", "calendarId")}} property.
+
+### Return value
+
+A new `Temporal.PlainDate` object, representing the date specified by the original `PlainDate`, interpreted in the new calendar system.
+
+### Exceptions
+
+- {{jsxref("TypeError")}}
+  - : Thrown if `calendar` is not a string.
+- {{jsxref("RangeError")}}
+  - : Thrown if `calendar` is not a valid calendar identifier.
+
+## Examples
+
+### Using withCalendar()
+
+```js
+const date = Temporal.PlainDate.from("2021-07-01");
+const newDate = date.withCalendar("islamic");
+console.log(newDate.toLocaleString("en-US", { calendar: "islamic" }));
+// 11/21/1442 AH
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal/PlainDate/with", "Temporal.PlainDate.prototype.with()")}}
+- {{jsxref("Temporal/PlainDate/from", "Temporal.PlainDate.from()")}}
+- {{jsxref("Temporal/PlainDate/calendarId", "Temporal.PlainDate.prototype.calendarId")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/year/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/year/index.md
new file mode 100644
index 000000000000000..6a83827aaeca2a0
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/year/index.md
@@ -0,0 +1,55 @@
+---
+title: Temporal.PlainDate.prototype.year
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate/year
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDate.year
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`year`** accessor property of {{jsxref("Temporal.PlainDate")}} instances returns an integer representing the number of years of this date relative to the start of a calendar-specific epoch year. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+This property has the same function as the {{jsxref("Temporal/PlainDate/era", "era")}}/{{jsxref("Temporal/PlainDate/eraYear", "eraYear")}} pair as a unique identifier of a year in a calendar. Usually year 1 is either the first year of the latest era or the ISO 8601 year `0001`. Because `year` is relative to the start of the epoch year, not the epoch date, if the epoch is in the middle of the year, that year will have the same value before and after the start date of the era.
+
+The set accessor of `year` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/PlainDate/with", "with()")}} method to create a new `Temporal.PlainDate` object with the desired new value.
+
+## Examples
+
+### Using year
+
+```js
+const date = Temporal.PlainDate.from("2021-07-01"); // ISO 8601 calendar
+console.log(date.year); // 2021
+
+const date2 = Temporal.PlainDate.from("-002021-07-01");
+console.log(date2.year); // -2021
+
+const date3 = Temporal.PlainDate.from("2021-07-01[u-ca=japanese]");
+console.log(date3.year); // 2021; although the Japanese calendar uses eras,
+// there's no obvious "default era", so the year is the same as the ISO year
+
+const date4 = Temporal.PlainDate.from("2021-07-01[u-ca=hebrew]");
+console.log(date4.year); // 5781; the Hebrew calendar uses the Anno Mundi epoch, which starts in 3761 BC
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal/PlainDate/with", "Temporal.PlainDate.prototype.with()")}}
+- {{jsxref("Temporal/PlainDate/add", "Temporal.PlainDate.prototype.add()")}}
+- {{jsxref("Temporal/PlainDate/subtract", "Temporal.PlainDate.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainDate/era", "Temporal.PlainDate.prototype.era")}}
+- {{jsxref("Temporal/PlainDate/eraYear", "Temporal.PlainDate.prototype.eraYear")}}
+- {{jsxref("Temporal/PlainDate/yearOfWeek", "Temporal.PlainDate.prototype.yearOfWeek")}}
+- {{jsxref("Temporal/PlainDate/month", "Temporal.PlainDate.prototype.month")}}
+- {{jsxref("Temporal/PlainDate/day", "Temporal.PlainDate.prototype.day")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/yearofweek/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/yearofweek/index.md
new file mode 100644
index 000000000000000..8bb460e89084a9c
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindate/yearofweek/index.md
@@ -0,0 +1,40 @@
+---
+title: Temporal.PlainDate.prototype.yearOfWeek
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate/yearOfWeek
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDate.yearOfWeek
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`yearOfWeek`** accessor property of {{jsxref("Temporal.PlainDate")}} instances returns an integer representing the year to be paired with the {{jsxref("Temporal/PlainDate/weekOfYear", "weekOfYear")}} of this date, or `undefined` if the calendar does not have a well-defined week system. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+Usually this is the year of the date, but for ISO 8601, the first and last few days of the year may be attributed to the last week of the previous year or the first week of the next year, causing the `yearOfWeek` to differ by 1. See {{jsxref("Temporal/PlainDate/weekOfYear", "weekOfYear")}} for more details.
+
+The set accessor of `yearOfWeek` is `undefined`. You cannot change this property directly.
+
+## Examples
+
+See the examples in the {{jsxref("Temporal/PlainDate/weekOfYear", "weekOfYear")}} page.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal/PlainDate/with", "Temporal.PlainDate.prototype.with()")}}
+- {{jsxref("Temporal/PlainDate/add", "Temporal.PlainDate.prototype.add()")}}
+- {{jsxref("Temporal/PlainDate/subtract", "Temporal.PlainDate.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainDate/year", "Temporal.PlainDate.prototype.year")}}
+- {{jsxref("Temporal/PlainDate/weekOfYear", "Temporal.PlainDate.prototype.weekOfYear")}}
+- {{jsxref("Temporal/PlainDate/dayOfWeek", "Temporal.PlainDate.prototype.dayOfWeek")}}
+- {{jsxref("Temporal/PlainDate/daysInWeek", "Temporal.PlainDate.prototype.daysInWeek")}}
+- {{jsxref("Temporal/PlainDate/daysInYear", "Temporal.PlainDate.prototype.daysInYear")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/add/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/add/index.md
new file mode 100644
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--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/add/index.md
@@ -0,0 +1,77 @@
+---
+title: Temporal.PlainDateTime.prototype.add()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/add
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.add
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`add()`** method of {{jsxref("Temporal.PlainDateTime")}} instances returns a new `Temporal.PlainDateTime` object representing this date-time moved forward by a given duration (in a form convertible by {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}).
+
+## Syntax
+
+```js-nolint
+add(duration)
+add(duration, options)
+```
+
+### Parameters
+
+- `duration`
+  - : A string, an object, or a {{jsxref("Temporal.Duration")}} instance representing a duration to add to this date-time. It is converted to a `Temporal.Duration` object using the same algorithm as {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}.
+- `options` {{optional_inline}}
+  - : An object containing the following property:
+    - `overflow` {{optional_inline}}
+      - : A string specifying the behavior when a date component is out of range. Possible values are:
+        - `"constrain"` (default)
+          - : The date component is [clamped](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate#invalid_date_clamping) to the valid range.
+        - `"reject"`
+          - : A {{jsxref("RangeError")}} is thrown if the date component is out of range.
+
+### Return value
+
+A new `Temporal.PlainDateTime` object representing the date-time specified by the original `PlainDateTime`, plus the duration.
+
+## Description
+
+For how [calendar durations](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#calendar_durations) are added, see {{jsxref("Temporal/PlainDate/add", "Temporal.PlainDate.prototype.add()")}}.
+
+Adding a duration is equivalent to [subtracting](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/subtract) its [negation](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration/negated).
+
+## Examples
+
+### Adding a duration
+
+```js
+const start = Temporal.PlainDateTime.from("2021-01-01T12:34:56");
+const end = start.add({
+  years: 1,
+  months: 2,
+  weeks: 3,
+  days: 4,
+  hours: 5,
+  minutes: 6,
+  seconds: 7,
+  milliseconds: 8,
+});
+console.log(end.toString()); // 2022-03-26T17:41:03.008
+```
+
+For more examples, especially with how different calendars and the `overflow` option interact with calendar durations, see {{jsxref("Temporal/PlainDate/add", "Temporal.PlainDate.prototype.add()")}}.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/PlainDateTime/subtract", "Temporal.PlainDateTime.prototype.subtract()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/calendarid/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/calendarid/index.md
new file mode 100644
index 000000000000000..c8dfbe53c67a966
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/calendarid/index.md
@@ -0,0 +1,43 @@
+---
+title: Temporal.PlainDateTime.prototype.calendarId
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/calendarId
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.calendarId
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`calendarId`** accessor property of {{jsxref("Temporal.PlainDateTime")}} instances returns a string representing the [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars) used to interpret the internal ISO 8601 date.
+
+For a list of commonly supported values, see {{jsxref("Intl/Locale/getCalendars", "Intl.Locale.prototype.getCalendars()")}}.
+
+The set accessor of `calendarId` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/PlainDateTime/withCalendar", "withCalendar()")}} method to create a new `Temporal.PlainDateTime` object with the desired new value.
+
+## Examples
+
+### Using calendarId
+
+```js
+const dt = Temporal.PlainDateTime.from("2021-07-01T08:00:00");
+console.log(dt.calendarId); // "iso8601"; default
+
+const dt2 = Temporal.PlainDateTime.from("2021-07-01T08:00:00[u-ca=chinese]");
+console.log(dt2.calendarId); // "chinese"
+
+const dt3 = dt2.withCalendar("hebrew");
+console.log(dt3.calendarId); // "hebrew"
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/compare/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/compare/index.md
new file mode 100644
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--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/compare/index.md
@@ -0,0 +1,94 @@
+---
+title: Temporal.PlainDateTime.compare()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/compare
+page-type: javascript-static-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.compare
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.PlainDateTime.compare()`** static method returns a number (-1, 0, or 1) indicating whether the first date-time comes before, is the same as, or comes after the second date-time. Equivalent to first comparing their dates, then comparing their times if the dates are the same.
+
+## Syntax
+
+```js-nolint
+Temporal.PlainDateTime.compare(dateTime1, dateTime2)
+```
+
+### Parameters
+
+- `dateTime1`
+  - : A string, an object, or a {{jsxref("Temporal.PlainDateTime")}} instance representing the first date-time to compare. It is converted to a `Temporal.PlainDateTime` object using the same algorithm as {{jsxref("Temporal/PlainDateTime/from", "Temporal.PlainDateTime.from()")}}.
+- `dateTime2`
+  - : The second date-time to compare, converted to a `Temporal.PlainDateTime` object using the same algorithm as `dateTime1`.
+
+### Return value
+
+Returns `-1` if `dateTime1` comes before `dateTime2`, `0` if they are the same, and `1` if `dateTime2` comes after. They are compared by their underlying date and time values, ignoring their calendars.
+
+## Examples
+
+### Using Temporal.PlainDateTime.compare()
+
+```js
+const dt1 = Temporal.PlainDateTime.from("2021-08-01T01:00:00");
+const dt2 = Temporal.PlainDateTime.from("2021-08-02T00:00:00");
+console.log(Temporal.PlainDateTime.compare(dt1, dt2)); // -1
+
+const dt3 = Temporal.PlainDateTime.from("2021-08-01T00:00:00");
+console.log(Temporal.PlainDateTime.compare(dt1, dt3)); // 1
+```
+
+### Comparing dates in different calendars
+
+```js
+const dt1 = Temporal.PlainDateTime.from({ year: 2021, month: 8, day: 1 });
+const dt2 = Temporal.PlainDateTime.from({
+  year: 2021,
+  month: 8,
+  day: 1,
+  calendar: "islamic",
+});
+const dt3 = Temporal.PlainDateTime.from({
+  year: 2021,
+  month: 8,
+  day: 1,
+  calendar: "hebrew",
+});
+console.log(dt1.toString()); // "2021-08-01T00:00:00"
+console.log(dt2.toString()); // "2582-12-17T00:00:00[u-ca=islamic]"
+console.log(dt3.toString()); // "-001739-04-06T00:00:00[u-ca=hebrew]"
+console.log(Temporal.PlainDateTime.compare(dt1, dt2)); // -1
+console.log(Temporal.PlainDateTime.compare(dt1, dt3)); // 1
+```
+
+### Sorting an array of date-times
+
+The purpose of this `compare()` function is to act as a comparator to be passed to {{jsxref("Array.prototype.sort()")}} and related functions.
+
+```js
+const dateTimes = [
+  Temporal.PlainDateTime.from("2021-08-01"),
+  Temporal.PlainDateTime.from("2021-08-02"),
+  Temporal.PlainDateTime.from("2021-08-01T01:00:00"),
+];
+
+dateTimes.sort(Temporal.PlainDateTime.compare);
+console.log(dateTimes.map((d) => d.toString()));
+// [ "2021-08-01T00:00:00", "2021-08-01T01:00:00", "2021-08-02T00:00:00" ]
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal/PlainDateTime/equals", "Temporal.PlainDateTime.prototype.equals()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/day/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/day/index.md
new file mode 100644
index 000000000000000..40ce67b4f364426
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/day/index.md
@@ -0,0 +1,46 @@
+---
+title: Temporal.PlainDateTime.prototype.day
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/day
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.day
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`day`** accessor property of {{jsxref("Temporal.PlainDateTime")}} instances returns a positive integer representing the 1-based day index in the month of this date, which is the same day number you would see on a calendar. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+The set accessor of `day` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/PlainDateTime/with", "with()")}} method to create a new `Temporal.PlainDateTime` object with the desired new value.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/day", "Temporal.PlainDate.prototype.day")}}.
+
+## Examples
+
+### Using day
+
+```js
+const dt = Temporal.PlainDateTime.from("2021-07-01"); // ISO 8601 calendar
+console.log(dt.day); // 1
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal/PlainDateTime/with", "Temporal.PlainDateTime.prototype.with()")}}
+- {{jsxref("Temporal/PlainDateTime/add", "Temporal.PlainDateTime.prototype.add()")}}
+- {{jsxref("Temporal/PlainDateTime/subtract", "Temporal.PlainDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainDateTime/year", "Temporal.PlainDateTime.prototype.year")}}
+- {{jsxref("Temporal/PlainDateTime/month", "Temporal.PlainDateTime.prototype.month")}}
+- {{jsxref("Temporal/PlainDateTime/daysInMonth", "Temporal.PlainDateTime.prototype.daysInMonth")}}
+- {{jsxref("Temporal/PlainDateTime/dayOfWeek", "Temporal.PlainDateTime.prototype.dayOfWeek")}}
+- {{jsxref("Temporal/PlainDateTime/dayOfYear", "Temporal.PlainDateTime.prototype.dayOfYear")}}
+- {{jsxref("Temporal/PlainDate/day", "Temporal.PlainDate.prototype.day")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/dayofweek/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/dayofweek/index.md
new file mode 100644
index 000000000000000..90e39dba93c4c46
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/dayofweek/index.md
@@ -0,0 +1,46 @@
+---
+title: Temporal.PlainDateTime.prototype.dayOfWeek
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/dayOfWeek
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.dayOfWeek
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`dayOfWeek`** accessor property of {{jsxref("Temporal.PlainDateTime")}} instances returns a positive integer representing the 1-based day index in the week of this date. Days in a week are numbered sequentially from `1` to {{jsxref("Temporal/PlainDateTime/daysInWeek", "daysInWeek")}}, with each number mapping to its name. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+The set accessor of `dayOfWeek` is `undefined`. You cannot change this property directly. To create a new `Temporal.PlainDateTime` object with the desired new `dayOfWeek` value, use the {{jsxref("Temporal/PlainDateTime/add", "add()")}} or {{jsxref("Temporal/PlainDateTime/subtract", "subtract()")}} method with the appropriate number of `days`.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/dayOfWeek", "Temporal.PlainDate.prototype.dayOfWeek")}}.
+
+## Examples
+
+### Using dayOfWeek
+
+```js
+const dt = Temporal.PlainDateTime.from("2021-07-01");
+console.log(dt.dayOfWeek); // 4; Thursday
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal/PlainDateTime/with", "Temporal.PlainDateTime.prototype.with()")}}
+- {{jsxref("Temporal/PlainDateTime/add", "Temporal.PlainDateTime.prototype.add()")}}
+- {{jsxref("Temporal/PlainDateTime/subtract", "Temporal.PlainDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainDateTime/day", "Temporal.PlainDateTime.prototype.day")}}
+- {{jsxref("Temporal/PlainDateTime/dayOfYear", "Temporal.PlainDateTime.prototype.dayOfYear")}}
+- {{jsxref("Temporal/PlainDateTime/daysInWeek", "Temporal.PlainDateTime.prototype.daysInWeek")}}
+- {{jsxref("Temporal/PlainDateTime/weekOfYear", "Temporal.PlainDateTime.prototype.weekOfYear")}}
+- {{jsxref("Temporal/PlainDateTime/yearOfWeek", "Temporal.PlainDateTime.prototype.yearOfWeek")}}
+- {{jsxref("Temporal/PlainDate/dayOfWeek", "Temporal.PlainDate.prototype.dayOfWeek")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/dayofyear/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/dayofyear/index.md
new file mode 100644
index 000000000000000..68c90ab42da0e33
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/dayofyear/index.md
@@ -0,0 +1,45 @@
+---
+title: Temporal.PlainDateTime.prototype.dayOfYear
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/dayOfYear
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.dayOfYear
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`dayOfYear`** accessor property of {{jsxref("Temporal.PlainDateTime")}} instances returns a positive integer representing the 1-based day index in the year of this date. The first day of this year is `1`, and the last day is the {{jsxref("Temporal/PlainDateTime/daysInYear", "daysInYear")}}. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+The set accessor of `dayOfYear` is `undefined`. You cannot change this property directly. To create a new `Temporal.PlainDateTime` object with the desired new `dayOfYear` value, use the {{jsxref("Temporal/PlainDateTime/add", "add()")}} or {{jsxref("Temporal/PlainDateTime/subtract", "subtract()")}} method with the appropriate number of `days`.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/dayOfYear", "Temporal.PlainDate.prototype.dayOfYear")}}.
+
+## Examples
+
+### Using dayOfYear
+
+```js
+const dt = Temporal.PlainDateTime.from("2021-07-01");
+console.log(dt.dayOfYear); // 182
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal/PlainDateTime/with", "Temporal.PlainDateTime.prototype.with()")}}
+- {{jsxref("Temporal/PlainDateTime/add", "Temporal.PlainDateTime.prototype.add()")}}
+- {{jsxref("Temporal/PlainDateTime/subtract", "Temporal.PlainDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainDateTime/year", "Temporal.PlainDateTime.prototype.year")}}
+- {{jsxref("Temporal/PlainDateTime/day", "Temporal.PlainDateTime.prototype.day")}}
+- {{jsxref("Temporal/PlainDateTime/dayOfWeek", "Temporal.PlainDateTime.prototype.dayOfWeek")}}
+- {{jsxref("Temporal/PlainDateTime/daysInYear", "Temporal.PlainDateTime.prototype.daysInYear")}}
+- {{jsxref("Temporal/PlainDate/dayOfYear", "Temporal.PlainDate.prototype.dayOfYear")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/daysinmonth/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/daysinmonth/index.md
new file mode 100644
index 000000000000000..3b79a69bcee8f44
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/daysinmonth/index.md
@@ -0,0 +1,46 @@
+---
+title: Temporal.PlainDateTime.prototype.daysInMonth
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/daysInMonth
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.daysInMonth
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`daysInMonth`** accessor property of {{jsxref("Temporal.PlainDateTime")}} instances returns a positive integer representing the number of days in the month of this date. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+The set accessor of `daysInMonth` is `undefined`. You cannot change this property directly.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/daysInMonth", "Temporal.PlainDate.prototype.daysInMonth")}}.
+
+## Examples
+
+### Using daysInMonth
+
+```js
+const dt = Temporal.PlainDateTime.from("2021-07-01");
+console.log(dt.daysInMonth); // 31
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal/PlainDateTime/with", "Temporal.PlainDateTime.prototype.with()")}}
+- {{jsxref("Temporal/PlainDateTime/add", "Temporal.PlainDateTime.prototype.add()")}}
+- {{jsxref("Temporal/PlainDateTime/subtract", "Temporal.PlainDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainDateTime/year", "Temporal.PlainDateTime.prototype.year")}}
+- {{jsxref("Temporal/PlainDateTime/month", "Temporal.PlainDateTime.prototype.month")}}
+- {{jsxref("Temporal/PlainDateTime/day", "Temporal.PlainDateTime.prototype.day")}}
+- {{jsxref("Temporal/PlainDateTime/daysInWeek", "Temporal.PlainDateTime.prototype.daysInWeek")}}
+- {{jsxref("Temporal/PlainDateTime/daysInYear", "Temporal.PlainDateTime.prototype.daysInYear")}}
+- {{jsxref("Temporal/PlainDate/daysInMonth", "Temporal.PlainDate.prototype.daysInMonth")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/daysinweek/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/daysinweek/index.md
new file mode 100644
index 000000000000000..0304e9f7c3564ce
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/daysinweek/index.md
@@ -0,0 +1,46 @@
+---
+title: Temporal.PlainDateTime.prototype.daysInWeek
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/daysInWeek
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.daysInWeek
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`daysInWeek`** accessor property of {{jsxref("Temporal.PlainDateTime")}} instances returns a positive integer representing the number of days in the week of this date. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+The set accessor of `daysInWeek` is `undefined`. You cannot change this property directly.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/daysInWeek", "Temporal.PlainDate.prototype.daysInWeek")}}.
+
+## Examples
+
+### Using daysInWeek
+
+```js
+const dt = Temporal.PlainDateTime.from("2021-07-01");
+console.log(dt.daysInWeek); // 7
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal/PlainDateTime/with", "Temporal.PlainDateTime.prototype.with()")}}
+- {{jsxref("Temporal/PlainDateTime/add", "Temporal.PlainDateTime.prototype.add()")}}
+- {{jsxref("Temporal/PlainDateTime/subtract", "Temporal.PlainDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainDateTime/yearOfWeek", "Temporal.PlainDateTime.prototype.yearOfWeek")}}
+- {{jsxref("Temporal/PlainDateTime/weekOfYear", "Temporal.PlainDateTime.prototype.weekOfYear")}}
+- {{jsxref("Temporal/PlainDateTime/dayOfWeek", "Temporal.PlainDateTime.prototype.dayOfWeek")}}
+- {{jsxref("Temporal/PlainDateTime/daysInMonth", "Temporal.PlainDateTime.prototype.daysInMonth")}}
+- {{jsxref("Temporal/PlainDateTime/daysInYear", "Temporal.PlainDateTime.prototype.daysInYear")}}
+- {{jsxref("Temporal/PlainDate/daysInWeek", "Temporal.PlainDate.prototype.daysInWeek")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/daysinyear/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/daysinyear/index.md
new file mode 100644
index 000000000000000..db2f9c06d60bf5d
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/daysinyear/index.md
@@ -0,0 +1,45 @@
+---
+title: Temporal.PlainDateTime.prototype.daysInYear
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/daysInYear
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.daysInYear
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`daysInYear`** accessor property of {{jsxref("Temporal.PlainDateTime")}} instances returns a positive integer representing the number of days in the year of this date. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+The set accessor of `daysInYear` is `undefined`. You cannot change this property directly.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/daysInYear", "Temporal.PlainDate.prototype.daysInYear")}}.
+
+## Examples
+
+### Using daysInYear
+
+```js
+const dt = Temporal.PlainDateTime.from("2021-07-01");
+console.log(dt.daysInYear); // 365
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal/PlainDateTime/with", "Temporal.PlainDateTime.prototype.with()")}}
+- {{jsxref("Temporal/PlainDateTime/add", "Temporal.PlainDateTime.prototype.add()")}}
+- {{jsxref("Temporal/PlainDateTime/subtract", "Temporal.PlainDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainDateTime/year", "Temporal.PlainDateTime.prototype.year")}}
+- {{jsxref("Temporal/PlainDateTime/dayOfYear", "Temporal.PlainDateTime.prototype.dayOfYear")}}
+- {{jsxref("Temporal/PlainDateTime/daysInMonth", "Temporal.PlainDateTime.prototype.daysInMonth")}}
+- {{jsxref("Temporal/PlainDateTime/daysInWeek", "Temporal.PlainDateTime.prototype.daysInWeek")}}
+- {{jsxref("Temporal/PlainDate/daysInYear", "Temporal.PlainDate.prototype.daysInYear")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/equals/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/equals/index.md
new file mode 100644
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--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/equals/index.md
@@ -0,0 +1,56 @@
+---
+title: Temporal.PlainDateTime.prototype.equals()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/equals
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.equals
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`equals()`** method of {{jsxref("Temporal.PlainDateTime")}} instances returns `true` if this date-time is equivalent in value to another date-time (in a form convertible by {{jsxref("Temporal/PlainDate/from", "Temporal.PlainDateTime.from()")}}), and `false` otherwise. They are compared both by their date and time values and their calendars, so two date-times from different calendars may be considered equal by {{jsxref("Temporal/PlainDateTime/compare", "Temporal.PlainDateTime.compare()")}} but not by `equals()`.
+
+## Syntax
+
+```js-nolint
+equals(other)
+```
+
+### Parameters
+
+- `other`
+  - : A string, an object, or a {{jsxref("Temporal.PlainDateTime")}} instance representing the other date-time to compare. It is converted to a `Temporal.PlainDateTime` object using the same algorithm as {{jsxref("Temporal/PlainDateTime/from", "Temporal.PlainDateTime.from()")}}.
+
+### Return value
+
+`true` if this date-time is equal to `other` both in their date/time value and their calendar, `false` otherwise.
+
+## Examples
+
+### Using equals()
+
+```js
+const dt1 = Temporal.PlainDateTime.from("2021-08-01");
+const dt2 = Temporal.PlainDateTime.from({ year: 2021, month: 8, day: 1 });
+console.log(dt1.equals(dt2)); // true
+
+const dt3 = Temporal.PlainDateTime.from("2021-08-01[u-ca=japanese]");
+console.log(dt1.equals(dt3)); // false
+
+const dt4 = Temporal.PlainDateTime.from("2021-08-01T01:00:00");
+console.log(dt1.equals(dt4)); // false
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal/PlainDateTime/compare", "Temporal.PlainDateTime.compare()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/era/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/era/index.md
new file mode 100644
index 000000000000000..b77518aa246f596
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/era/index.md
@@ -0,0 +1,46 @@
+---
+title: Temporal.PlainDateTime.prototype.era
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/era
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.era
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`era`** accessor property of {{jsxref("Temporal.PlainDateTime")}} instances returns a calendar-specific lowercase string representing the era of this date, or `undefined` if the calendar does not use eras (e.g. ISO 8601). `era` and `eraYear` together uniquely identify a year in a calendar, in the same way that `year` does. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+The set accessor of `era` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/PlainDateTime/with", "with()")}} method to create a new `Temporal.PlainDateTime` object with the desired new value.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/era", "Temporal.PlainDate.prototype.era")}}.
+
+## Examples
+
+### Using era
+
+```js
+const dt = Temporal.PlainDateTime.from("2021-07-01"); // ISO 8601 calendar
+console.log(dt.era); // undefined
+
+const dt2 = Temporal.PlainDateTime.from("2021-07-01[u-ca=gregory]");
+console.log(dt2.era); // gregory
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal/PlainDateTime/with", "Temporal.PlainDateTime.prototype.with()")}}
+- {{jsxref("Temporal/PlainDateTime/add", "Temporal.PlainDateTime.prototype.add()")}}
+- {{jsxref("Temporal/PlainDateTime/subtract", "Temporal.PlainDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainDateTime/year", "Temporal.PlainDateTime.prototype.year")}}
+- {{jsxref("Temporal/PlainDateTime/eraYear", "Temporal.PlainDateTime.prototype.eraYear")}}
+- {{jsxref("Temporal/PlainDate/era", "Temporal.PlainDate.prototype.era")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/erayear/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/erayear/index.md
new file mode 100644
index 000000000000000..00cccbaf317bdca
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/erayear/index.md
@@ -0,0 +1,52 @@
+---
+title: Temporal.PlainDateTime.prototype.eraYear
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/eraYear
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.eraYear
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`eraYear`** accessor property of {{jsxref("Temporal.PlainDateTime")}} instances returns a non-negative integer representing the year of this date within the era, or `undefined` if the calendar does not use eras (e.g. ISO 8601). The year index usually starts from 1 (more common) or 0, and years in an era can decrease with time (e.g. Gregorian BCE). `era` and `eraYear` together uniquely identify a year in a calendar, in the same way that `year` does. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+The set accessor of `eraYear` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/PlainDateTime/with", "with()")}} method to create a new `Temporal.PlainDateTime` object with the desired new value.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/eraYear", "Temporal.PlainDate.prototype.eraYear")}}.
+
+## Examples
+
+### Using eraYear
+
+```js
+const dt = Temporal.PlainDateTime.from("2021-07-01"); // ISO 8601 calendar
+console.log(dt.eraYear); // undefined
+
+const dt2 = Temporal.PlainDateTime.from("2021-07-01[u-ca=gregory]");
+console.log(dt2.eraYear); // 2021
+
+const dt3 = Temporal.PlainDateTime.from("-002021-07-01[u-ca=gregory]");
+console.log(dt3.eraYear); // 2022; 0000 is used for the year 1 BC
+
+const dt4 = Temporal.PlainDateTime.from("2021-07-01[u-ca=japanese]");
+console.log(dt4.eraYear); // 3
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal/PlainDateTime/with", "Temporal.PlainDateTime.prototype.with()")}}
+- {{jsxref("Temporal/PlainDateTime/add", "Temporal.PlainDateTime.prototype.add()")}}
+- {{jsxref("Temporal/PlainDateTime/subtract", "Temporal.PlainDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainDateTime/year", "Temporal.PlainDateTime.prototype.year")}}
+- {{jsxref("Temporal/PlainDateTime/era", "Temporal.PlainDateTime.prototype.era")}}
+- {{jsxref("Temporal/PlainDate/eraYear", "Temporal.PlainDate.prototype.eraYear")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/from/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/from/index.md
new file mode 100644
index 000000000000000..25af195e143ea1c
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/from/index.md
@@ -0,0 +1,92 @@
+---
+title: Temporal.PlainDateTime.from()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/from
+page-type: javascript-static-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.from
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.PlainDateTime.from()`** static method creates a new `Temporal.PlainDateTime` object from another `Temporal.PlainDateTime` object, an object with date and time properties, or an [RFC 9557](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime#rfc_9557_format) string.
+
+## Syntax
+
+```js-nolint
+Temporal.PlainDateTime.from(info)
+Temporal.PlainDateTime.from(info, options)
+```
+
+### Parameters
+
+- `info`
+  - : One of the following:
+    - A {{jsxref("Temporal.PlainDateTime")}} instance, which creates a copy of the instance.
+    - An [RFC 9557](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime#rfc_9557_format) string containing a date, optionally a time, and optionally a calendar.
+    - An object containing properties that are recognized by either {{jsxref("Temporal/PlainDate/from", "Temporal.PlainDate.from()")}} (`calendar`, `era`, `eraYear`, `year`, `month`, `monthCode`, `day`) or {{jsxref("Temporal/PlainTime/from", "Temporal.PlainTime.from()")}} (`hour`, `minute`, `second`, `millisecond`, `microsecond`, `nanosecond`). The info should explicitly specify a year (as `year` or `era` and `eraYear`), a month (as `month` or `monthCode`), and a day; others are optional and will be set to their default values.
+- `options` {{optional_inline}}
+  - : An object containing the following property:
+    - `overflow` {{optional_inline}}
+      - : A string specifying the behavior when a date component is out of range (when using the object `info`). Possible values are:
+        - `"constrain"` (default)
+          - : The date component is [clamped](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate#invalid_date_clamping) to the valid range.
+        - `"reject"`
+          - : A {{jsxref("RangeError")}} is thrown if the date component is out of range.
+
+### Return value
+
+A new `Temporal.PlainDateTime` object, representing the date and time specified by `info` in the specified `calendar`.
+
+### Exceptions
+
+- {{jsxref("TypeError")}}
+  - : Thrown in one of the following cases:
+    - `info` is not an object or a string.
+    - `options` is not an object or `undefined`.
+    - The provided properties are insufficient to unambiguously determine a date. You usually need to provide a `year` (or `era` and `eraYear`), a `month` (or `monthCode`), and a `day`.
+- {{jsxref("RangeError")}}
+  - : Thrown in one of the following cases:
+    - The provided properties that specify the same component are inconsistent.
+    - The provided non-numerical properties are not valid; for example, if `monthCode` is never a valid month code in this calendar.
+    - The provided numerical properties are out of range, and `options.overflow` is set to `"reject"`.
+
+## Examples
+
+### Creating a PlainDateTime from an object
+
+```js
+// Year + month + day + hour + minute + second
+const dt = Temporal.PlainDateTime.from({
+  year: 2021,
+  month: 7,
+  day: 1,
+  hour: 12,
+  minute: 34,
+  second: 56,
+});
+console.log(dt.toString()); // "2021-07-01T12:34:56"
+```
+
+### Creating a PlainDateTime from a string
+
+```js
+const dt = Temporal.PlainDateTime.from("2021-07-01T12:34:56");
+console.log(dt.toLocaleString()); // "7/1/2021, 12:34:56 PM" (assuming en-US locale)
+```
+
+For more examples, especially regarding different calendars and overflow settings, see {{jsxref("Temporal/PlainDate/from", "Temporal.PlainDate.from()")}} and {{jsxref("Temporal/PlainTime/from", "Temporal.PlainTime.from()")}}.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal/PlainDateTime/PlainDateTime", "Temporal.PlainDateTime()")}}
+- {{jsxref("Temporal/PlainDateTime/with", "Temporal.PlainDateTime.prototype.with()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/hour/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/hour/index.md
new file mode 100644
index 000000000000000..fa25ac88d293037
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/hour/index.md
@@ -0,0 +1,41 @@
+---
+title: Temporal.PlainDateTime.prototype.hour
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/hour
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.hour
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`hour`** accessor property of {{jsxref("Temporal.PlainDateTime")}} instances returns a integer from 0 to 23 representing the hour component of this time.
+
+The set accessor of `hour` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/PlainDateTime/with", "with()")}} method to create a new `Temporal.PlainDateTime` object with the desired new value.
+
+For general information and more examples, see {{jsxref("Temporal/PlainTime/hour", "Temporal.PlainTime.prototype.hour")}}.
+
+## Examples
+
+### Using hour
+
+```js
+const dt = Temporal.PlainDateTime.from("2021-07-01T12:34:56.123456789");
+console.log(dt.hour); // 12
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal/PlainDateTime/with", "Temporal.PlainDateTime.prototype.with()")}}
+- {{jsxref("Temporal/PlainDateTime/add", "Temporal.PlainDateTime.prototype.add()")}}
+- {{jsxref("Temporal/PlainDateTime/subtract", "Temporal.PlainDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainTime/hour", "Temporal.PlainTime.prototype.hour")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/index.md
new file mode 100644
index 000000000000000..f8215d41ccf01dc
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/index.md
@@ -0,0 +1,163 @@
+---
+title: Temporal.PlainDateTime
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime
+page-type: javascript-class
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.PlainDateTime`** object represents a date (calendar date) and time (wall-clock time) without a time zone. It is fundamentally represented as a combination of a [date](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate) (with an associated calendar system) and a [time](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainTime).
+
+## Description
+
+A `PlainDateTime` is essentially the combination of a {{jsxref("Temporal.PlainDate")}} and a {{jsxref("Temporal.PlainTime")}}. Because the date and time information don't have much interaction, all general information about date properties is documented in the `PlainDate` object, and all general information about time properties is documented in the `PlainTime` object.
+
+If the date-time represents a specific instant that should remain invariant across time zones, you should use the {{jsxref("Temporal.ZonedDateTime")}} object instead. Use `PlainDateTime` when you need to represent an event happening at a specific wall-clock time that may be a different instant in different time zones.
+
+### RFC 9557 format
+
+`PlainDateTime` objects can be serialized and parsed using the [RFC 9557](https://datatracker.ietf.org/doc/html/rfc9557) format, an extension to the [ISO 8601 / RFC 3339](https://datatracker.ietf.org/doc/html/rfc3339) format. The string has the following form (spaces are only for readability and should not be present in the actual string):
+
+```plain
+YYYY-MM-DD T HH:mm:ss.sssssssss [u-ca=calendar_id]
+```
+
+- `YYYY`
+  - : Either a four-digit number, or a six-digit number with a `+` or `-` sign.
+- `MM`
+  - : A two-digit number from `01` to `12`.
+- `DD`
+  - : A two-digit number from `01` to `31`. The `YYYY`, `MM`, and `DD` components can be separated by `-` or nothing.
+- `T` {{optional_inline}}
+  - : The date-time separator, which can be `T`, `t`, or a space. Present if and only if `HH` is present.
+- `HH` {{optional_inline}}
+  - : A two-digit number from `00` to `23`. Defaults to `00`.
+- `mm` {{optional_inline}}
+  - : A two-digit number from `00` to `59`. Defaults to `00`.
+- `ss.sssssssss` {{optional_inline}}
+  - : A two-digit number from `00` to `59`. May optionally be followed by a `.` or `,` and one to nine digits. Defaults to `00`. The `HH`, `mm`, and `ss` components can be separated by `:` or nothing. You can omit either just `ss` or both `ss` and `mm`, so the time can be one of three forms: `HH`, `HH:mm`, or `HH:mm:ss.sssssssss`.
+- `[u-ca=calendar_id]` {{optional_inline}}
+  - : Replace `calendar_id` with the calendar to use. May have a _critical flag_ by prefixing the key with `!`: e.g., `[!u-ca=iso8601]`. This flag generally tells other systems that it cannot be ignored if they don't support it. The `Temporal` parser will throw an error if the annotations contain two or more calendar annotations and one of them is critical. Defaults to `[u-ca=iso8601]`. Note that the `YYYY-MM-DD` is always interpreted as an ISO 8601 calendar date and then converted to the specified calendar.
+
+As an input, you may optionally include the offset and time zone identifier, in the same format as [`ZonedDateTime`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#rfc_9557_format), but they will be ignored. Note that the offset must _not_ be `Z`. Other annotations in the `[key=value]` format are also ignored, and they must not have the critical flag.
+
+When serializing, you can configure the fractional second digits, whether to display the calendar ID, and whether to add a critical flag for it.
+
+## Constructor
+
+- {{jsxref("Temporal/PlainDateTime/PlainDateTime", "Temporal.PlainDateTime()")}} {{experimental_inline}}
+  - : Creates a new `Temporal.PlainDateTime` object by directly supplying the underlying data.
+
+## Static methods
+
+- {{jsxref("Temporal/PlainDateTime/compare", "Temporal.PlainDateTime.compare()")}} {{experimental_inline}}
+  - : Returns a number (-1, 0, or 1) indicating whether the first date-time comes before, is the same as, or comes after the second date-time. Equivalent to first comparing their dates, then comparing their times if the dates are the same.
+- {{jsxref("Temporal/PlainDateTime/from", "Temporal.PlainDateTime.from()")}} {{experimental_inline}}
+  - : Creates a new `Temporal.PlainDateTime` object from another `Temporal.PlainDateTime` object, an object with date and time properties, or an [RFC 9557](#rfc_9557_format) string.
+
+## Instance properties
+
+These properties are defined on `Temporal.PlainDateTime.prototype` and shared by all `Temporal.PlainDateTime` instances.
+
+- {{jsxref("Temporal/PlainDateTime/calendarId", "Temporal.PlainDateTime.prototype.calendarId")}} {{experimental_inline}}
+  - : Returns a string representing the [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars) used to interpret the internal ISO 8601 date.
+- {{jsxref("Object/constructor", "Temporal.PlainDateTime.prototype.constructor")}}
+  - : The constructor function that created the instance object. For `Temporal.PlainDateTime` instances, the initial value is the {{jsxref("Temporal/PlainDateTime/PlainDateTime", "Temporal.PlainDateTime()")}} constructor.
+- {{jsxref("Temporal/PlainDateTime/day", "Temporal.PlainDateTime.prototype.day")}} {{experimental_inline}}
+  - : Returns a positive integer representing the 1-based day index in the month of this date, which is the same day number you would see on a calendar. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. Generally starts at 1 and is continuous, but not always.
+- {{jsxref("Temporal/PlainDateTime/dayOfWeek", "Temporal.PlainDateTime.prototype.dayOfWeek")}} {{experimental_inline}}
+  - : Returns a positive integer representing the 1-based day index in the week of this date. Days in a week are numbered sequentially from `1` to {{jsxref("Temporal/PlainDateTime/daysInWeek", "daysInWeek")}}, with each number mapping to its name. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. 1 usually represents Monday in the calendar, even when locales using the calendar may consider a different day as the first day of the week (see {{jsxref("Intl/Locale/getWeekInfo", "Intl.Locale.prototype.getWeekInfo()")}}).
+- {{jsxref("Temporal/PlainDateTime/dayOfYear", "Temporal.PlainDateTime.prototype.dayOfYear")}} {{experimental_inline}}
+  - : Returns a positive integer representing the 1-based day index in the year of this date. The first day of this year is `1`, and the last day is the {{jsxref("Temporal/PlainDateTime/daysInYear", "daysInYear")}}. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+- {{jsxref("Temporal/PlainDateTime/daysInMonth", "Temporal.PlainDateTime.prototype.daysInMonth")}} {{experimental_inline}}
+  - : Returns a positive integer representing the number of days in the month of this date. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+- {{jsxref("Temporal/PlainDateTime/daysInWeek", "Temporal.PlainDateTime.prototype.daysInWeek")}} {{experimental_inline}}
+  - : Returns a positive integer representing the number of days in the week of this date. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. For the ISO 8601 calendar, this is always 7, but in other calendar systems it may differ from week to week.
+- {{jsxref("Temporal/PlainDateTime/daysInYear", "Temporal.PlainDateTime.prototype.daysInYear")}} {{experimental_inline}}
+  - : Returns a positive integer representing the number of days in the year of this date. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. For the ISO 8601 calendar, this is 365, or 366 in a leap year.
+- {{jsxref("Temporal/PlainDateTime/era", "Temporal.PlainDateTime.prototype.era")}} {{experimental_inline}}
+  - : Returns a calendar-specific lowercase string representing the era of this date, or `undefined` if the calendar does not use eras (e.g. ISO 8601). `era` and `eraYear` together uniquely identify a year in a calendar, in the same way that `year` does. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. For Gregorian, it is either `"gregory"` or `"gregory-inverse"`.
+- {{jsxref("Temporal/PlainDateTime/eraYear", "Temporal.PlainDateTime.prototype.eraYear")}} {{experimental_inline}}
+  - : Returns a non-negative integer representing the year of this date within the era, or `undefined` if the calendar does not use eras (e.g. ISO 8601). The year index usually starts from 1 (more common) or 0, and years in an era can decrease with time (e.g. Gregorian BCE). `era` and `eraYear` together uniquely identify a year in a calendar, in the same way that `year` does. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+- {{jsxref("Temporal/PlainDateTime/hour", "Temporal.PlainDateTime.prototype.hour")}} {{experimental_inline}}
+  - : Returns a integer from 0 to 23 representing the hour component of this time.
+- {{jsxref("Temporal/PlainDateTime/inLeapYear", "Temporal.PlainDateTime.prototype.inLeapYear")}} {{experimental_inline}}
+  - : Returns a boolean indicating whether this date is in a leap year. A leap year is a year that has more days (due to a leap day or leap month) than a common year. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+- {{jsxref("Temporal/PlainDateTime/microsecond", "Temporal.PlainDateTime.prototype.microsecond")}} {{experimental_inline}}
+  - : Returns a integer from 0 to 999 representing the microsecond (10<sup>-6</sup> second) component of this time.
+- {{jsxref("Temporal/PlainDateTime/millisecond", "Temporal.PlainDateTime.prototype.millisecond")}} {{experimental_inline}}
+  - : Returns a integer from 0 to 999 representing the millisecond (10<sup>-3</sup> second) component of this time.
+- {{jsxref("Temporal/PlainDateTime/minute", "Temporal.PlainDateTime.prototype.minute")}} {{experimental_inline}}
+  - : Returns a integer from 0 to 59 representing the minute component of this time.
+- {{jsxref("Temporal/PlainDateTime/month", "Temporal.PlainDateTime.prototype.month")}} {{experimental_inline}}
+  - : Returns a positive integer representing the 1-based month index in the year of this date. The first month of this year is `1`, and the last month is the {{jsxref("Temporal/PlainDateTime/monthsInYear", "monthsInYear")}}. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. Note that unlike {{jsxref("Date.prototype.getMonth()")}}, the index is 1-based. If the calendar has leap months, then the month with the same {{jsxref("Temporal/PlainDateTime/monthCode", "monthCode")}} may have different `month` indexes for different years.
+- {{jsxref("Temporal/PlainDateTime/monthCode", "Temporal.PlainDateTime.prototype.monthCode")}} {{experimental_inline}}
+  - : Returns a calendar-specific string representing the month of this date. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. Usually it is `M` plus a two-digit month number. For leap months, it is the previous month's code followed by `L`. If the leap month is the first month of the year, the code is `M00L`.
+- {{jsxref("Temporal/PlainDateTime/monthsInYear", "Temporal.PlainDateTime.prototype.monthsInYear")}} {{experimental_inline}}
+  - : Returns a positive integer representing the number of months in the year of this date. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. For the ISO 8601 calendar, this is always 12, but in other calendar systems it may differ.
+- {{jsxref("Temporal/PlainDateTime/nanosecond", "Temporal.PlainDateTime.prototype.nanosecond")}} {{experimental_inline}}
+  - : Returns a integer from 0 to 999 representing the nanosecond (10<sup>-9</sup> second) component of this time.
+- {{jsxref("Temporal/PlainDateTime/second", "Temporal.PlainDateTime.prototype.second")}} {{experimental_inline}}
+  - : Returns a integer from 0 to 59 representing the second component of this time.
+- {{jsxref("Temporal/PlainDateTime/weekOfYear", "Temporal.PlainDateTime.prototype.weekOfYear")}} {{experimental_inline}}
+  - : Returns a positive integer representing the 1-based week index in the {{jsxref("Temporal/PlainDateTime/yearOfWeek", "yearOfWeek")}} of this date, or `undefined` if the calendar does not have a well-defined week system. The first week of the year is `1`. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. Note that for ISO 8601, the first and last few days of the year may be attributed to the last week of the previous year or the first week of the next year.
+- {{jsxref("Temporal/PlainDateTime/year", "Temporal.PlainDateTime.prototype.year")}} {{experimental_inline}}
+  - : Returns an integer representing the number of years of this date relative to the start of a calendar-specific epoch year. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. Usually year 1 is either the first year of the latest era or the ISO 8601 year `0001`. If the epoch is in the middle of the year, that year will have the same value before and after the start date of the era.
+- {{jsxref("Temporal/PlainDateTime/yearOfWeek", "Temporal.PlainDateTime.prototype.yearOfWeek")}} {{experimental_inline}}
+  - : Returns an integer representing the year to be paired with the {{jsxref("Temporal/PlainDateTime/weekOfYear", "weekOfYear")}} of this date, or `undefined` if the calendar does not have a well-defined week system. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. Usually this is the year of the date, but for ISO 8601, the first and last few days of the year may be attributed to the last week of the previous year or the first week of the next year, causing the `yearOfWeek` to differ by 1.
+- `Temporal.PlainDateTime.prototype[Symbol.toStringTag]`
+  - : The initial value of the [`[Symbol.toStringTag]`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol/toStringTag) property is the string `"Temporal.PlainDateTime"`. This property is used in {{jsxref("Object.prototype.toString()")}}.
+
+## Instance methods
+
+- {{jsxref("Temporal/PlainDateTime/add", "Temporal.PlainDateTime.prototype.add()")}} {{experimental_inline}}
+  - : Returns a new `Temporal.PlainDateTime` object representing this date-time moved forward by a given duration (in a form convertible by {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}).
+- {{jsxref("Temporal/PlainDateTime/equals", "Temporal.PlainDateTime.prototype.equals()")}} {{experimental_inline}}
+  - : Returns `true` if this date-time is equivalent in value to another date-time (in a form convertible by {{jsxref("Temporal/PlainDate/from", "Temporal.PlainDate.from()")}}), and `false` otherwise. They are compared both by their date and time values and their calendars, so two date-times from different calendars may be considered equal by {{jsxref("Temporal/PlainDateTime/compare", "Temporal.PlainDateTime.compare()")}} but not by `equals()`.
+- {{jsxref("Temporal/PlainDateTime/round", "Temporal.PlainDateTime.prototype.round()")}} {{experimental_inline}}
+  - : Returns a new `Temporal.PlainDateTime` object representing this date-time rounded to the given unit.
+- {{jsxref("Temporal/PlainDateTime/since", "Temporal.PlainDateTime.prototype.since()")}} {{experimental_inline}}
+  - : Returns a new {{jsxref("Temporal.Duration")}} object representing the duration from another date-time (in a form convertible by {{jsxref("Temporal/PlainDateTime/from", "Temporal.PlainDateTime.from()")}}) to this date-time. The duration is positive if the other date-time is before this date-time, and negative if after.
+- {{jsxref("Temporal/PlainDateTime/subtract", "Temporal.PlainDateTime.prototype.subtract()")}} {{experimental_inline}}
+  - : Returns a new `Temporal.PlainDateTime` object representing this date-time moved backward by a given duration (in a form convertible by {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}).
+- {{jsxref("Temporal/PlainDateTime/toJSON", "Temporal.PlainDateTime.prototype.toJSON()")}} {{experimental_inline}}
+  - : Returns a string representing this date-time in the same [RFC 9557 format](#rfc_9557_format) as calling {{jsxref("Temporal/PlainDateTime/toString", "toString()")}}. Intended to be implicitly called by {{jsxref("JSON.stringify()")}}.
+- {{jsxref("Temporal/PlainDateTime/toLocaleString", "Temporal.PlainDateTime.prototype.toLocaleString()")}} {{experimental_inline}}
+  - : Returns a string with a language-sensitive representation of this date-time.
+- {{jsxref("Temporal/PlainDateTime/toPlainDate", "Temporal.PlainDateTime.prototype.toPlainDate()")}} {{experimental_inline}}
+  - : Returns a new {{jsxref("Temporal.PlainDate")}} object representing the date part (year, month, day) of this date-time in the same calendar system.
+- {{jsxref("Temporal/PlainDateTime/toPlainTime", "Temporal.PlainDateTime.prototype.toPlainTime()")}} {{experimental_inline}}
+  - : Returns a new {{jsxref("Temporal.PlainTime")}} object representing the time part (hour, minute, second, and subsecond components) of this date-time.
+- {{jsxref("Temporal/PlainDateTime/toString", "Temporal.PlainDateTime.prototype.toString()")}} {{experimental_inline}}
+  - : Returns a string representing this date-time in the [RFC 9557 format](#rfc_9557_format).
+- {{jsxref("Temporal/PlainDateTime/toZonedDateTime", "Temporal.PlainDateTime.prototype.toZonedDateTime()")}} {{experimental_inline}}
+  - : Returns a new {{jsxref("Temporal.ZonedDateTime")}} instance representing the same date-time as this plain date-time, but in the specified time zone.
+- {{jsxref("Temporal/PlainDateTime/until", "Temporal.PlainDateTime.prototype.until()")}} {{experimental_inline}}
+  - : Returns a new {{jsxref("Temporal.Duration")}} object representing the duration from this date-time to another date-time (in a form convertible by {{jsxref("Temporal/PlainDateTime/from", "Temporal.PlainDateTime.from()")}}). The duration is positive if the other date-time is after this date-time, and negative if before.
+- {{jsxref("Temporal/PlainDateTime/valueOf", "Temporal.PlainDateTime.prototype.valueOf()")}} {{experimental_inline}}
+  - : Throws a {{jsxref("TypeError")}}, which prevents `Temporal.PlainDateTime` instances from being [implicitly converted to primitives](/en-US/docs/Web/JavaScript/Data_structures#primitive_coercion) when used in arithmetic or comparison operations.
+- {{jsxref("Temporal/PlainDateTime/with", "Temporal.PlainDateTime.prototype.with()")}} {{experimental_inline}}
+  - : Returns a new `Temporal.PlainDateTime` object representing this date-time with some fields replaced by new values.
+- {{jsxref("Temporal/PlainDateTime/withCalendar", "Temporal.PlainDateTime.prototype.withCalendar()")}} {{experimental_inline}}
+  - : Returns a new `Temporal.PlainDateTime` object representing this date-time interpreted in the new calendar system.
+- {{jsxref("Temporal/PlainDateTime/withPlainTime", "Temporal.PlainDateTime.prototype.withPlainTime()")}} {{experimental_inline}}
+  - : Returns a new `Temporal.PlainDateTime` object representing this date-time with the time part entirely replaced by the new time (in a form convertible by {{jsxref("Temporal/PlainTime/from", "Temporal.PlainTime.from()")}}).
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal")}}
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal.PlainTime")}}
+- {{jsxref("Temporal.ZonedDateTime")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/inleapyear/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/inleapyear/index.md
new file mode 100644
index 000000000000000..e8d20b303e6db66
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/inleapyear/index.md
@@ -0,0 +1,46 @@
+---
+title: Temporal.PlainDateTime.prototype.inLeapYear
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/inLeapYear
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.inLeapYear
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`inLeapYear`** accessor property of {{jsxref("Temporal.PlainDateTime")}} instances returns a boolean indicating whether this date is in a leap year. A leap year is a year that has more days (due to a leap day or leap month) than a common year. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+The set accessor of `inLeapYear` is `undefined`. You cannot change this property directly.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/inLeapYear", "Temporal.PlainDate.prototype.inLeapYear")}}.
+
+## Examples
+
+### Using inLeapYear
+
+```js
+const dt = Temporal.PlainDateTime.from("2021-07-01");
+console.log(dt.inLeapYear); // false
+console.log(dt.daysInYear); // 365
+console.log(dt.monthsInYear); // 12
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal/PlainDateTime/with", "Temporal.PlainDateTime.prototype.with()")}}
+- {{jsxref("Temporal/PlainDateTime/add", "Temporal.PlainDateTime.prototype.add()")}}
+- {{jsxref("Temporal/PlainDateTime/subtract", "Temporal.PlainDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainDateTime/year", "Temporal.PlainDateTime.prototype.year")}}
+- {{jsxref("Temporal/PlainDateTime/daysInYear", "Temporal.PlainDateTime.prototype.daysInYear")}}
+- {{jsxref("Temporal/PlainDateTime/monthsInYear", "Temporal.PlainDateTime.prototype.monthsInYear")}}
+- {{jsxref("Temporal/PlainDate/inLeapYear", "Temporal.PlainDate.prototype.inLeapYear")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/microsecond/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/microsecond/index.md
new file mode 100644
index 000000000000000..db5d234885f09da
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/microsecond/index.md
@@ -0,0 +1,44 @@
+---
+title: Temporal.PlainDateTime.prototype.microsecond
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/microsecond
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.microsecond
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`microsecond`** accessor property of {{jsxref("Temporal.PlainDateTime")}} instances returns a integer from 0 to 999 representing the microsecond (10<sup>-6</sup> second) component of this time.
+
+The set accessor of `microsecond` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/PlainDateTime/with", "with()")}} method to create a new `Temporal.PlainDateTime` object with the desired new value.
+
+For general information and more examples, see {{jsxref("Temporal/PlainTime/microsecond", "Temporal.PlainTime.prototype.microsecond")}}.
+
+## Examples
+
+### Using microsecond
+
+```js
+const dt = Temporal.PlainDateTime.from("2021-07-01T12:34:56.123456789");
+console.log(dt.microsecond); // 456
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal/PlainDateTime/with", "Temporal.PlainDateTime.prototype.with()")}}
+- {{jsxref("Temporal/PlainDateTime/add", "Temporal.PlainDateTime.prototype.add()")}}
+- {{jsxref("Temporal/PlainDateTime/subtract", "Temporal.PlainDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainDateTime/second", "Temporal.PlainDateTime.prototype.second")}}
+- {{jsxref("Temporal/PlainDateTime/millisecond", "Temporal.PlainDateTime.prototype.millisecond")}}
+- {{jsxref("Temporal/PlainDateTime/nanosecond", "Temporal.PlainDateTime.prototype.nanosecond")}}
+- {{jsxref("Temporal/PlainTime/microsecond", "Temporal.PlainTime.prototype.microsecond")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/millisecond/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/millisecond/index.md
new file mode 100644
index 000000000000000..b0e496e5daeba9e
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/millisecond/index.md
@@ -0,0 +1,44 @@
+---
+title: Temporal.PlainDateTime.prototype.millisecond
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/millisecond
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.millisecond
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`millisecond`** accessor property of {{jsxref("Temporal.PlainDateTime")}} instances returns a integer from 0 to 999 representing the millisecond (10<sup>-3</sup> second) component of this time.
+
+The set accessor of `millisecond` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/PlainDateTime/with", "with()")}} method to create a new `Temporal.PlainDateTime` object with the desired new value.
+
+For general information and more examples, see {{jsxref("Temporal/PlainTime/millisecond", "Temporal.PlainTime.prototype.millisecond")}}.
+
+## Examples
+
+### Using millisecond
+
+```js
+const dt = Temporal.PlainDateTime.from("2021-07-01T12:34:56.123456789");
+console.log(dt.millisecond); // 123
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal/PlainDateTime/with", "Temporal.PlainDateTime.prototype.with()")}}
+- {{jsxref("Temporal/PlainDateTime/add", "Temporal.PlainDateTime.prototype.add()")}}
+- {{jsxref("Temporal/PlainDateTime/subtract", "Temporal.PlainDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainDateTime/second", "Temporal.PlainDateTime.prototype.second")}}
+- {{jsxref("Temporal/PlainDateTime/microsecond", "Temporal.PlainDateTime.prototype.microsecond")}}
+- {{jsxref("Temporal/PlainDateTime/nanosecond", "Temporal.PlainDateTime.prototype.nanosecond")}}
+- {{jsxref("Temporal/PlainTime/millisecond", "Temporal.PlainTime.prototype.millisecond")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/minute/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/minute/index.md
new file mode 100644
index 000000000000000..cd6ebca958e2f08
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/minute/index.md
@@ -0,0 +1,41 @@
+---
+title: Temporal.PlainDateTime.prototype.minute
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/minute
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.minute
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`minute`** accessor property of {{jsxref("Temporal.PlainDateTime")}} instances returns a integer from 0 to 59 representing the minute component of this time.
+
+The set accessor of `minute` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/PlainDateTime/with", "with()")}} method to create a new `Temporal.PlainDateTime` object with the desired new value.
+
+For general information and more examples, see {{jsxref("Temporal/PlainTime/minute", "Temporal.PlainTime.prototype.minute")}}.
+
+## Examples
+
+### Using minute
+
+```js
+const dt = Temporal.PlainDateTime.from("2021-07-01T12:34:56.123456789");
+console.log(dt.minute); // 34
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal/PlainDateTime/with", "Temporal.PlainDateTime.prototype.with()")}}
+- {{jsxref("Temporal/PlainDateTime/add", "Temporal.PlainDateTime.prototype.add()")}}
+- {{jsxref("Temporal/PlainDateTime/subtract", "Temporal.PlainDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainTime/minute", "Temporal.PlainDateTime.prototype.minute")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/month/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/month/index.md
new file mode 100644
index 000000000000000..11f70444d566216
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/month/index.md
@@ -0,0 +1,47 @@
+---
+title: Temporal.PlainDateTime.prototype.month
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/month
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.month
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`month`** accessor property of {{jsxref("Temporal.PlainDateTime")}} instances returns a positive integer representing the 1-based month index in the year of this date. The first month of this year is `1`, and the last month is the {{jsxref("Temporal/PlainDateTime/monthsInYear", "monthsInYear")}}. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+The set accessor of `month` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/PlainDateTime/with", "with()")}} method to create a new `Temporal.PlainDateTime` object with the desired new value.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/month", "Temporal.PlainDate.prototype.month")}}.
+
+## Examples
+
+### Using month
+
+```js
+const dt = Temporal.PlainDateTime.from("2021-07-01"); // ISO 8601 calendar
+console.log(dt.monthCode); // "M07"
+console.log(dt.month); // 7
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal/PlainDateTime/with", "Temporal.PlainDateTime.prototype.with()")}}
+- {{jsxref("Temporal/PlainDateTime/add", "Temporal.PlainDateTime.prototype.add()")}}
+- {{jsxref("Temporal/PlainDateTime/subtract", "Temporal.PlainDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainDateTime/year", "Temporal.PlainDateTime.prototype.year")}}
+- {{jsxref("Temporal/PlainDateTime/day", "Temporal.PlainDateTime.prototype.day")}}
+- {{jsxref("Temporal/PlainDateTime/monthCode", "Temporal.PlainDateTime.prototype.monthCode")}}
+- {{jsxref("Temporal/PlainDateTime/daysInMonth", "Temporal.PlainDateTime.prototype.daysInMonth")}}
+- {{jsxref("Temporal/PlainDateTime/monthsInYear", "Temporal.PlainDateTime.prototype.monthsInYear")}}
+- {{jsxref("Temporal/PlainDate/month", "Temporal.PlainDate.prototype.month")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/monthcode/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/monthcode/index.md
new file mode 100644
index 000000000000000..1f34ec0ed93f6b1
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/monthcode/index.md
@@ -0,0 +1,48 @@
+---
+title: Temporal.PlainDateTime.prototype.monthCode
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/monthCode
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.monthCode
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`monthCode`** accessor property of {{jsxref("Temporal.PlainDateTime")}} instances returns a calendar-specific string representing the month of this date. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+Usually it is `M` plus a two-digit month number. For leap months, it is the previous month's code followed by `L` (even if it's conceptually a derivative of the following month; for example, in the Hebrew calendar, Adar I has code `M05L` but Adar II has code `M06`). If the leap month is the first month of the year, the code is `M00L`.
+
+The set accessor of `monthCode` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/PlainDateTime/with", "with()")}} method to create a new `Temporal.PlainDateTime` object with the desired new value.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/monthCode", "Temporal.PlainDate.prototype.monthCode")}}.
+
+## Examples
+
+### Using monthCode
+
+```js
+const date = Temporal.PlainDateTime.from("2021-07-01"); // ISO 8601 calendar
+console.log(date.monthCode); // "M07"
+console.log(date.month); // 7
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal/PlainDateTime/with", "Temporal.PlainDateTime.prototype.with()")}}
+- {{jsxref("Temporal/PlainDateTime/add", "Temporal.PlainDateTime.prototype.add()")}}
+- {{jsxref("Temporal/PlainDateTime/subtract", "Temporal.PlainDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainDateTime/year", "Temporal.PlainDateTime.prototype.year")}}
+- {{jsxref("Temporal/PlainDateTime/month", "Temporal.PlainDateTime.prototype.month")}}
+- {{jsxref("Temporal/PlainDateTime/daysInMonth", "Temporal.PlainDateTime.prototype.daysInMonth")}}
+- {{jsxref("Temporal/PlainDateTime/monthsInYear", "Temporal.PlainDateTime.prototype.monthsInYear")}}
+- {{jsxref("Temporal/PlainDate/monthCode", "Temporal.PlainDate.prototype.monthCode")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/monthsinyear/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/monthsinyear/index.md
new file mode 100644
index 000000000000000..51f9413b5e65892
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/monthsinyear/index.md
@@ -0,0 +1,45 @@
+---
+title: Temporal.PlainDateTime.prototype.monthsInYear
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/monthsInYear
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.monthsInYear
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`monthsInYear`** accessor property of {{jsxref("Temporal.PlainDateTime")}} instances returns a positive integer representing the number of months in the year of this date. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+The set accessor of `monthsInYear` is `undefined`. You cannot change this property directly.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/monthsInYear", "Temporal.PlainDate.prototype.monthsInYear")}}.
+
+## Examples
+
+### Using monthsInYear
+
+```js
+const dt = Temporal.PlainDateTime.from("2021-07-01");
+console.log(dt.monthsInYear); // 12
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal/PlainDateTime/with", "Temporal.PlainDateTime.prototype.with()")}}
+- {{jsxref("Temporal/PlainDateTime/add", "Temporal.PlainDateTime.prototype.add()")}}
+- {{jsxref("Temporal/PlainDateTime/subtract", "Temporal.PlainDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainDateTime/year", "Temporal.PlainDateTime.prototype.year")}}
+- {{jsxref("Temporal/PlainDateTime/month", "Temporal.PlainDateTime.prototype.month")}}
+- {{jsxref("Temporal/PlainDateTime/monthCode", "Temporal.PlainDateTime.prototype.monthCode")}}
+- {{jsxref("Temporal/PlainDateTime/daysInMonth", "Temporal.PlainDateTime.prototype.daysInMonth")}}
+- {{jsxref("Temporal/PlainDate/monthsInYear", "Temporal.PlainDate.prototype.monthsInYear")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/nanosecond/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/nanosecond/index.md
new file mode 100644
index 000000000000000..8b282547fabd479
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/nanosecond/index.md
@@ -0,0 +1,44 @@
+---
+title: Temporal.PlainDateTime.prototype.nanosecond
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/nanosecond
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.nanosecond
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`nanosecond`** accessor property of {{jsxref("Temporal.PlainDateTime")}} instances returns a integer from 0 to 999 representing the nanosecond (10<sup>-9</sup> second) component of this time.
+
+The set accessor of `nanosecond` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/PlainDateTime/with", "with()")}} method to create a new `Temporal.PlainDateTime` object with the desired new value.
+
+For general information and more examples, see {{jsxref("Temporal/PlainTime/nanosecond", "Temporal.PlainTime.prototype.nanosecond")}}.
+
+## Examples
+
+### Using nanosecond
+
+```js
+const dt = Temporal.PlainDateTime.from("2021-07-01T12:34:56.123456789");
+console.log(dt.nanosecond); // 789
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal/PlainDateTime/with", "Temporal.PlainDateTime.prototype.with()")}}
+- {{jsxref("Temporal/PlainDateTime/add", "Temporal.PlainDateTime.prototype.add()")}}
+- {{jsxref("Temporal/PlainDateTime/subtract", "Temporal.PlainDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainDateTime/second", "Temporal.PlainDateTime.prototype.second")}}
+- {{jsxref("Temporal/PlainDateTime/millisecond", "Temporal.PlainDateTime.prototype.millisecond")}}
+- {{jsxref("Temporal/PlainDateTime/microsecond", "Temporal.PlainDateTime.prototype.microsecond")}}
+- {{jsxref("Temporal/PlainTime/nanosecond", "Temporal.PlainTime.prototype.nanosecond")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/plaindatetime/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/plaindatetime/index.md
new file mode 100644
index 000000000000000..5a76977f6145649
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/plaindatetime/index.md
@@ -0,0 +1,86 @@
+---
+title: Temporal.PlainDateTime()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/PlainDateTime
+page-type: javascript-constructor
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.PlainDateTime
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.PlainDateTime()`** constructor creates {{jsxref("Temporal.PlainDateTime")}} objects.
+
+This constructor allows you to create instances by directly supplying the underlying data. Like all other `Temporal` classes, you should usually construct `Temporal.PlainDateTime` objects using the {{jsxref("Temporal/PlainDateTime/from", "Temporal.PlainDateTime.from()")}} static method, which can handle a variety of input types.
+
+## Syntax
+
+```js-nolint
+new Temporal.PlainDateTime(year, month, day)
+new Temporal.PlainDateTime(year, month, day, hour)
+new Temporal.PlainDateTime(year, month, day, hour, minute)
+new Temporal.PlainDateTime(year, month, day, hour, minute, second)
+new Temporal.PlainDateTime(year, month, day, hour, minute, second, millisecond)
+new Temporal.PlainDateTime(year, month, day, hour, minute, second, millisecond, microsecond)
+new Temporal.PlainDateTime(year, month, day, hour, minute, second, millisecond, microsecond, nanosecond)
+new Temporal.PlainDateTime(year, month, day, hour, minute, second, millisecond, microsecond, nanosecond, calendar)
+```
+
+> **Note:** `Temporal.PlainDateTime()` can only be constructed with [`new`](/en-US/docs/Web/JavaScript/Reference/Operators/new). Attempting to call it without `new` throws a {{jsxref("TypeError")}}.
+
+### Parameters
+
+- `year`
+  - : A number, truncated to an integer, representing the year in the ISO calendar system.
+- `month`
+  - : A number, truncated to an integer, representing the month in the ISO calendar system.
+- `day`
+  - : A number, truncated to an integer, representing the day of the month in the ISO calendar system.
+- `hour` {{optional_inline}}
+  - : A number, truncated to an integer, representing the hour component.
+- `minute` {{optional_inline}}
+  - : A number, truncated to an integer, representing the minute component.
+- `second` {{optional_inline}}
+  - : A number, truncated to an integer, representing the second component.
+- `millisecond` {{optional_inline}}
+  - : A number, truncated to an integer, representing the millisecond component.
+- `microsecond` {{optional_inline}}
+  - : A number, truncated to an integer, representing the microsecond component.
+- `nanosecond` {{optional_inline}}
+  - : A number, truncated to an integer, representing the nanosecond component.
+- `calendar` {{optional_inline}}
+  - : A string representing the [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars) to use. Note that irrespective of the `calendar`, the `year`, `month`, and `day` must be in the ISO 8601 calendar system. Defaults to `"iso8601"`.
+
+### Return value
+
+A new `Temporal.PlainDateTime` object, representing the date-time specified by the parameters.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown if any of the components is not a finite number, or they don't represent a valid date-time.
+
+## Examples
+
+### Using Temporal.PlainDateTime()
+
+```js
+const dt = new Temporal.PlainDateTime(2021, 7, 1);
+console.log(dt.toString()); // 2021-07-01T00:00:00
+
+const dt2 = new Temporal.PlainDateTime(2021, 7, 1, 0, 0, 0, 0, 0, 0, "hebrew");
+console.log(dt2.toString()); // 2021-07-01T00:00:00[u-ca=hebrew]
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal/PlainDateTime/from", "Temporal.PlainDateTime.from()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/round/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/round/index.md
new file mode 100644
index 000000000000000..2cd81b2048aad55
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/round/index.md
@@ -0,0 +1,72 @@
+---
+title: Temporal.PlainDateTime.prototype.round()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/round
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.round
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`round()`** method of {{jsxref("Temporal.PlainDateTime")}} instances returns a new `Temporal.PlainDateTime` object representing this date-time rounded to the given unit.
+
+## Syntax
+
+```js-nolint
+round(smallestUnit)
+round(options)
+```
+
+### Parameters
+
+- `smallestUnit`
+  - : A string representing the [`smallestUnit`](#smallestunit_2) option. This is a convenience overload, so `round(smallestUnit)` is equivalent to `round({ smallestUnit })`, where `smallestUnit` is a string.
+- `options`
+  - : An object containing some or all of the following properties (in the order they are retrieved and validated):
+    - `roundingIncrement` {{optional_inline}}
+      - : A number (truncated to an integer) representing the rounding increment in the given `smallestUnit`. Defaults to `1`. For all values of `smallestUnit` except `"day"`, the increment must be a divisor of the maximum value of the unit; for example, if the unit is hours, the increment must be a divisor of 24 and must not be 24 itself, which means it can be 1, 2, 3, 4, 6, 8, or 12. For `"day"`, the increment must be 1.
+    - `roundingMode` {{optional_inline}}
+      - : A string specifying how to round off the fractional part of `smallestUnit`. See [`Intl.NumberFormat()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/NumberFormat/NumberFormat#roundingmode). Defaults to `"halfExpand"`.
+    - `smallestUnit`
+      - : A string representing the smallest unit to include in the output. The value must be one of the following: `"day"`, `"hour"`, `"minute"`, `"second"`, `"millisecond"`, `"microsecond"`, `"nanosecond"`, or their plural forms. For units larger than `"nanosecond"`, fractional parts of the `smallestUnit` will be rounded according to the `roundingIncrement` and `roundingMode` settings.
+
+### Return value
+
+A new {{jsxref("Temporal.PlainDateTime")}} object representing this date-time rounded to the given unit, where all units smaller than `smallestUnit` are zeroed out.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown if any of the options is invalid.
+
+## Examples
+
+### Rounding off small units
+
+```js
+const dt = Temporal.PlainDateTime.from("2021-07-01T12:34:56.123456789");
+const nearestMillisecond = dt.round("millisecond");
+console.log(nearestMillisecond.toString()); // 2021-07-01T12:34:56.123
+
+const nearestHalfHour = dt.round({
+  smallestUnit: "minute",
+  roundingIncrement: 30,
+});
+console.log(nearestHalfHour.toString()); // 2021-07-01T12:30:00
+
+const nextDay = dt.round({ smallestUnit: "day", roundingMode: "ceil" });
+console.log(nextDay.toString()); // 2021-07-02T00:00:00
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/second/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/second/index.md
new file mode 100644
index 000000000000000..d1eb3302502242d
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/second/index.md
@@ -0,0 +1,44 @@
+---
+title: Temporal.PlainDateTime.prototype.second
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/second
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.second
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`second`** accessor property of {{jsxref("Temporal.PlainDateTime")}} instances returns a integer from 0 to 59 representing the second component of this time.
+
+The set accessor of `second` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/PlainDateTime/with", "with()")}} method to create a new `Temporal.PlainDateTime` object with the desired new value.
+
+For general information and more examples, see {{jsxref("Temporal/PlainTime/second", "Temporal.PlainTime.prototype.second")}}.
+
+## Examples
+
+### Using second
+
+```js
+const dt = Temporal.PlainDateTime.from("2021-07-01T12:34:56.123456789");
+console.log(dt.second); // 56
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal/PlainDateTime/with", "Temporal.PlainDateTime.prototype.with()")}}
+- {{jsxref("Temporal/PlainDateTime/add", "Temporal.PlainDateTime.prototype.add()")}}
+- {{jsxref("Temporal/PlainDateTime/subtract", "Temporal.PlainDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainDateTime/millisecond", "Temporal.PlainDateTime.prototype.millisecond")}}
+- {{jsxref("Temporal/PlainDateTime/microsecond", "Temporal.PlainDateTime.prototype.microsecond")}}
+- {{jsxref("Temporal/PlainDateTime/nanosecond", "Temporal.PlainDateTime.prototype.nanosecond")}}
+- {{jsxref("Temporal/PlainTime/second", "Temporal.PlainTime.prototype.second")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/since/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/since/index.md
new file mode 100644
index 000000000000000..7056ab72a31e162
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/since/index.md
@@ -0,0 +1,100 @@
+---
+title: Temporal.PlainDateTime.prototype.since()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/since
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.since
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`since()`** method of {{jsxref("Temporal.PlainDateTime")}} instances returns a new {{jsxref("Temporal.Duration")}} object representing the duration from another date-time (in a form convertible by {{jsxref("Temporal/PlainDateTime/from", "Temporal.PlainDateTime.from()")}}) to this date-time. The duration is positive if the other date-time is before this date-time, and negative if after.
+
+This method does `this - other`. To do `other - this`, use the {{jsxref("Temporal/PlainDateTime/until", "until()")}} method.
+
+## Syntax
+
+```js-nolint
+since(other)
+since(other, options)
+```
+
+### Parameters
+
+- `other`
+  - : A string, an object, or a {{jsxref("Temporal.PlainDateTime")}} instance representing a date-time to subtract from this date-time. It is converted to a `Temporal.PlainDateTime` object using the same algorithm as {{jsxref("Temporal/PlainDateTime/from", "Temporal.PlainDateTime.from()")}}. It must have the same calendar as `this`.
+- `options` {{optional_inline}}
+  - : An object containing the options for {{jsxref("Temporal/Duration/round", "Temporal.Duration.prototype.round()")}}, which includes `largestUnit`, `roundingIncrement`, `roundingMode`, and `smallestUnit`. `largestUnit` and `smallestUnit` accept all possible units. For `largestUnit`, the default value `"auto"` means `"day"` or `smallestUnit`, whichever is greater. For `smallestUnit`, the default value is `"nanosecond"`. The current date is used as the `relativeTo` option. Note that using [units larger than `"day"`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#calendar_durations) may make the duration not portable to other calendars or dates.
+
+### Return value
+
+A new {{jsxref("Temporal.Duration")}} object representing the duration _since_ `other` to this date-time. The duration is positive if `other` is before this date-time, and negative if after.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown in one of the following cases:
+    - `other` has a different calendar than `this`.
+    - Any of the options is invalid.
+
+## Examples
+
+### Using since()
+
+```js
+let lastBilling = Temporal.PlainDateTime.from({
+  year: Temporal.Now.plainDateISO().year,
+  month: 4,
+  day: 1,
+});
+const now = Temporal.Now.plainDateTimeISO().round("second");
+if (Temporal.PlainDateTime.compare(lastBilling, now) > 0) {
+  lastBilling = lastBilling.subtract({ years: 1 });
+}
+const duration = now.since(lastBilling);
+console.log(`${duration.toLocaleString("en-US")} since last billing`);
+// Expected output: "[number] days, [number] hr, [number] min, [number] sec since last billing"
+
+const duration2 = now.since(lastBilling, { smallestUnit: "day" });
+console.log(`${duration2.toLocaleString("en-US")} since last billing`);
+// Expected output: "[number] days since last billing
+
+const duration3 = now.since(lastBilling, {
+  largestUnit: "year",
+  smallestUnit: "day",
+});
+console.log(`${duration3.toLocaleString("en-US")} since last billing`);
+// Expected output: "[number] months, [number] days since last billing"
+```
+
+### Rounding the result
+
+By default the fractional part of the `smallestUnit` is truncated. You can round it up using the `roundingIncrement` and `roundingMode` options.
+
+```js
+const dt1 = Temporal.PlainDateTime.from("2022-01-01T00:00:00");
+const dt2 = Temporal.PlainDateTime.from("2022-01-28T12:34:56");
+const duration = dt2.since(dt1, {
+  smallestUnit: "day",
+  roundingIncrement: 5,
+  roundingMode: "ceil",
+});
+console.log(duration.toString()); // "P30D"
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/PlainDateTime/add", "Temporal.PlainDateTime.prototype.add()")}}
+- {{jsxref("Temporal/PlainDateTime/subtract", "Temporal.PlainDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainDateTime/until", "Temporal.PlainDateTime.prototype.until()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/subtract/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/subtract/index.md
new file mode 100644
index 000000000000000..8deca8a765e56e2
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/subtract/index.md
@@ -0,0 +1,77 @@
+---
+title: Temporal.PlainDateTime.prototype.subtract()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/subtract
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.subtract
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`subtract()`** method of {{jsxref("Temporal.PlainDateTime")}} instances returns a new `Temporal.PlainDateTime` object representing this date-time moved backward by a given duration (in a form convertible by {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}).
+
+If you want to subtract two date-times and get a duration, use {{jsxref("Temporal/PlainDateTime/since", "since()")}} or {{jsxref("Temporal/PlainDateTime/until", "until()")}} instead.
+
+## Syntax
+
+```js-nolint
+subtract(duration)
+subtract(duration, options)
+```
+
+### Parameters
+
+- `duration`
+  - : A string, an object, or a {{jsxref("Temporal.Duration")}} instance representing a duration to subtract from this date-time. It is converted to a `Temporal.Duration` object using the same algorithm as {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}.
+- `options` {{optional_inline}}
+  - : An object containing the following property:
+    - `overflow` {{optional_inline}}
+      - : A string specifying the behavior when a date component is out of range. Possible values are:
+        - `"constrain"` (default)
+          - : The date component is [clamped](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate#invalid_date_clamping) to the valid range.
+        - `"reject"`
+          - : A {{jsxref("RangeError")}} is thrown if the date component is out of range.
+
+### Return value
+
+A new `Temporal.PlainDateTime` object representing the date-time specified by the original `PlainDateTime`, minus the duration.
+
+## Description
+
+Subtracting a duration is equivalent to [adding](Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/add) its [negation](Web/JavaScript/Reference/Global_Objects/Temporal/Duration/negated), so all the same considerations apply.
+
+## Examples
+
+### Subtracting a duration
+
+```js
+const start = Temporal.PlainDateTime.from("2022-01-01T12:34:56");
+const end = start.subtract({
+  years: 1,
+  months: 2,
+  weeks: 3,
+  days: 4,
+  hours: 5,
+  minutes: 6,
+  seconds: 7,
+  milliseconds: 8,
+});
+console.log(end.toString()); // 2020-10-07T07:28:48.992
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/PlainDateTime/add", "Temporal.PlainDateTime.prototype.add()")}}
+- {{jsxref("Temporal/PlainDateTime/since", "Temporal.PlainDateTime.prototype.since()")}}
+- {{jsxref("Temporal/PlainDateTime/until", "Temporal.PlainDateTime.prototype.until()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/tojson/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/tojson/index.md
new file mode 100644
index 000000000000000..187826e9f06a141
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/tojson/index.md
@@ -0,0 +1,70 @@
+---
+title: Temporal.PlainDateTime.prototype.toJSON()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/toJSON
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.toJSON
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toJSON()`** method of {{jsxref("Temporal.PlainDateTime")}} instances returns a string representing this date-time in the same [RFC 9557 format](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime#rfc_9557_format) as calling {{jsxref("Temporal/PlainDateTime/toString", "toString()")}}. It is intended to be implicitly called by {{jsxref("JSON.stringify()")}}.
+
+## Syntax
+
+```js-nolint
+toJSON()
+```
+
+### Parameters
+
+None.
+
+### Return value
+
+A string representing the given date-time in the [RFC 9557 format](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime#rfc_9557_format), with the calendar annotation included if it is not `"iso8601"`.
+
+## Description
+
+The `toJSON()` method is automatically called by {{jsxref("JSON.stringify()")}} when a `Temporal.PlainDateTime` object is stringified. This method is generally intended to, by default, usefully serialize `Temporal.PlainDateTime` objects during [JSON](/en-US/docs/Glossary/JSON) serialization, which can then be deserialized using the {{jsxref("Temporal/PlainDateTime/from", "Temporal.PlainDateTime.from()")}} function as the reviver of {{jsxref("JSON.parse()")}}.
+
+## Examples
+
+### Using toJSON()
+
+```js
+const dt = Temporal.PlainDateTime.from({ year: 2021, month: 8, day: 1 });
+const dtStr = dt.toJSON(); // '2021-08-01T00:00:00'
+const dt2 = Temporal.PlainDateTime.from(dtStr);
+```
+
+### JSON serialization and parsing
+
+This example shows how `Temporal.PlainDateTime` can be serialized as JSON without extra effort, and how to parse it back.
+
+```js
+const dt = Temporal.PlainDateTime.from({ year: 2021, month: 8, day: 1 });
+const jsonStr = JSON.stringify({ nextBilling: dt }); // '{"nextBilling":"2021-08-01T00:00:00"}'
+const obj = JSON.parse(jsonStr, (key, value) => {
+  if (key === "nextBilling") {
+    return Temporal.PlainDateTime.from(value);
+  }
+  return value;
+});
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal/PlainDateTime/from", "Temporal.PlainDateTime.from()")}}
+- {{jsxref("Temporal/PlainDateTime/toString", "Temporal.PlainDateTime.prototype.toString()")}}
+- {{jsxref("Temporal/PlainDateTime/toLocaleString", "Temporal.PlainDateTime.prototype.toLocaleString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/tolocalestring/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/tolocalestring/index.md
new file mode 100644
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--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/tolocalestring/index.md
@@ -0,0 +1,110 @@
+---
+title: Temporal.PlainDateTime.prototype.toLocaleString()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/toLocaleString
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.toLocaleString
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toLocaleString()`** method of {{jsxref("Temporal.PlainDateTime")}} instances returns a string with a language-sensitive representation of this date-time. In implementations with [`Intl.DateTimeFormat` API](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat) support, this method delegates to `Intl.DateTimeFormat`.
+
+Every time `toLocaleString` is called, it has to perform a search in a big database of localization strings, which is potentially inefficient. When the method is called many times with the same arguments, it is better to create a {{jsxref("Intl.DateTimeFormat")}} object and use its {{jsxref("Intl/DateTimeFormat/format", "format()")}} method, because a `DateTimeFormat` object remembers the arguments passed to it and may decide to cache a slice of the database, so future `format` calls can search for localization strings within a more constrained context.
+
+## Syntax
+
+```js-nolint
+toLocaleString()
+toLocaleString(locales)
+toLocaleString(locales, options)
+```
+
+### Parameters
+
+The `locales` and `options` parameters customize the behavior of the function and let applications specify the language whose formatting conventions should be used.
+
+In implementations that support the [`Intl.DateTimeFormat` API](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat), these parameters correspond exactly to the [`Intl.DateTimeFormat()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat/DateTimeFormat) constructor's parameters. Implementations without `Intl.DateTimeFormat` support return the exact same string as {{jsxref("Temporal/PlainDateTime/toString", "toString()")}}, ignoring both parameters.
+
+- `locales` {{optional_inline}}
+  - : A string with a BCP 47 language tag, or an array of such strings. Corresponds to the [`locales`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat/DateTimeFormat#locales) parameter of the `Intl.DateTimeFormat()` constructor.
+- `options` {{optional_inline}}
+
+  - : An object adjusting the output format. Corresponds to the [`options`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat/DateTimeFormat#options) parameter of the `Intl.DateTimeFormat()` constructor. If this date-time's calendar is not `"iso8601"`, the `calendar` option must be provided with the same value; otherwise, if this date-time's calendar is `"iso8601"`, the `calendar` option can be any value. Regarding the [date-time component options](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat/DateTimeFormat#date-time_component_options) and the style shortcuts (`dateStyle` and `timeStyle`), the options should follow one of these forms:
+
+    - Provide none of them: `year`, `month`, `day`, `hour`, `minute`, and `second` will default to `"numeric"`.
+    - Provide at least one of `dateStyle` or `timeStyle`: the date-time components will be set according to the specified style and the locale.
+    - Provide some date-time component options. Only the specified date-time components will be included in the output.
+
+See the [`Intl.DateTimeFormat()` constructor](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat/DateTimeFormat) for details on these parameters and how to use them.
+
+### Return value
+
+A string representing the given date-time according to language-specific conventions.
+
+In implementations with `Intl.DateTimeFormat`, this is equivalent to `new Intl.DateTimeFormat(locales, options).format(dateTime)`, where `options` has been normalized as described above.
+
+> [!NOTE]
+> Most of the time, the formatting returned by `toLocaleString()` is consistent. However, the output may vary between implementations, even within the same locale — output variations are by design and allowed by the specification. It may also not be what you expect. For example, the string may use non-breaking spaces or be surrounded by bidirectional control characters. You should not compare the results of `toLocaleString()` to hardcoded constants.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown if any of the options is invalid.
+- {{jsxref("TypeError")}}
+  - : Thrown if any of the options is not of the expected type.
+
+## Examples
+
+### Using toLocaleString()
+
+Basic use of this method without specifying a `locale` returns a formatted string in the default locale and with default options.
+
+```js
+const dt = Temporal.PlainDateTime.from("2021-08-01T12:34:56");
+
+console.log(dt.toLocaleString()); // 8/1/2021, 12:34:56 PM (assuming en-US locale)
+```
+
+If the date's calendar doesn't match the locale's default calendar, and the date's calendar is not `iso8601`, an explicit `calendar` option must be provided with the same value.
+
+```js
+const dt = Temporal.PlainDateTime.from("2021-08-01T12:34:56[u-ca=japanese]");
+// The ja-JP locale uses the Gregorian calendar by default
+dt.toLocaleString("ja-JP", { calendar: "japanese" }); // R3/8/1 12:34:56
+```
+
+### Using toLocaleString() with options
+
+You can customize which parts of the date are included in the output by providing the `options` parameter.
+
+```js
+const dt = Temporal.PlainDateTime.from("2021-08-01T12:34:56");
+dt.toLocaleString("en-US", { dateStyle: "full", timeStyle: "full" }); // Sunday, August 1, 2021 at 12:34:56 PM
+dt.toLocaleString("en-US", {
+  year: "numeric",
+  month: "long",
+  hour: "numeric",
+}); // August 2021 at 12 PM
+dt.toLocaleString("en-US", {
+  year: "numeric",
+  hour: "numeric",
+  minute: "numeric",
+}); // 2021, 12:34 PM
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Intl.DateTimeFormat")}}
+- {{jsxref("Temporal/PlainDateTime/toJSON", "Temporal.PlainDateTime.prototype.toJSON()")}}
+- {{jsxref("Temporal/PlainDateTime/toString", "Temporal.PlainDateTime.prototype.toString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/toplaindate/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/toplaindate/index.md
new file mode 100644
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@@ -0,0 +1,52 @@
+---
+title: Temporal.PlainDateTime.prototype.toPlainDate()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/toPlainDate
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.toPlainDate
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toPlainDate()`** method of {{jsxref("Temporal.PlainDateTime")}} instances returns a new {{jsxref("Temporal.PlainDate")}} object representing the date part (year, month, day) of this date-time in the same calendar system.
+
+## Syntax
+
+```js-nolint
+toPlainDate()
+```
+
+### Parameters
+
+None.
+
+### Return value
+
+A new `Temporal.PlainDate` object representing the date part (year, month, day) of this date-time in the same calendar system.
+
+## Examples
+
+### Using toPlainDate()
+
+```js
+const dt = Temporal.PlainDateTime.from("2021-07-01T12:34:56");
+const date = dt.toPlainDate();
+console.log(date.toString()); // '2021-07-01'
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal/PlainDateTime/toPlainTime", "Temporal.PlainDateTime.prototype.toPlainTime()")}}
+- {{jsxref("Temporal/PlainDateTime/toZonedDateTime", "Temporal.PlainDate.prototype.toZonedDateTime()")}}
+- {{jsxref("Temporal/PlainDate/toPlainDateTime", "Temporal.PlainDate.prototype.toPlainDateTime()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/toplaintime/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/toplaintime/index.md
new file mode 100644
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--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/toplaintime/index.md
@@ -0,0 +1,51 @@
+---
+title: Temporal.PlainDateTime.prototype.toPlainTime()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/toPlainTime
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.toPlainTime
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toPlainTime()`** method of {{jsxref("Temporal.PlainDateTime")}} instances returns a new {{jsxref("Temporal.PlainTime")}} object representing the time part (hour, minute, second, and subsecond components) of this date-time.
+
+## Syntax
+
+```js-nolint
+toPlainTime()
+```
+
+### Parameters
+
+None.
+
+### Return value
+
+A new `Temporal.PlainTime` object representing the time part (hour, minute, second, and subsecond components) of this date-time.
+
+## Examples
+
+### Using toPlainTime()
+
+```js
+const dt = Temporal.PlainDateTime.from("2021-07-01T12:34:56");
+const time = dt.toPlainTime();
+console.log(time.toString()); // '12:34:56'
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal.PlainTime")}}
+- {{jsxref("Temporal/PlainDateTime/toPlainDate", "Temporal.PlainDateTime.prototype.toPlainDate()")}}
+- {{jsxref("Temporal/PlainDateTime/toZonedDateTime", "Temporal.PlainDateTime.prototype.toZonedDateTime()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/tostring/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/tostring/index.md
new file mode 100644
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--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/tostring/index.md
@@ -0,0 +1,77 @@
+---
+title: Temporal.PlainDateTime.prototype.toString()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/toString
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.toString
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toString()`** method of {{jsxref("Temporal.PlainDateTime")}} instances returns a string representing this date-time in the [RFC 9557 format](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime#rfc_9557_format).
+
+## Syntax
+
+```js-nolint
+toString()
+toString(options)
+```
+
+### Parameters
+
+- `options` {{optional_inline}}
+  - : An object containing the following property:
+    - `calendarName` {{optional_inline}}
+      - : Whether to show the calendar annotation (`[u-ca=calendar_id]`) in the return value. Possible values are:
+        - `"auto"` (default)
+          - : Include the calendar annotation if the calendar is not `"iso8601"`.
+        - `"always"`
+          - : Always include the calendar annotation.
+        - `"never"`
+          - : Never include the calendar annotation. This makes the returned string not recoverable to the same {{jsxref("Temporal.PlainDateTime")}} instance, although the date value still remains the same.
+        - `"critical"`
+          - : Always include the calendar annotation, and add a critical flag: `[!u-ca=calendar_id]`. Useful when sending the string to certain systems, but not useful for Temporal itself.
+    - `fractionalSecondDigits` {{optional_inline}}
+      - : Either an integer from 0 to 9, or the string `"auto"`. The default is `"auto"`. If `"auto"`, then trailing zeros are removed from the fractional seconds. Otherwise, the fractional part of the second component contains this many digits, padded with zeros or rounded as necessary.
+    - `roundingMode` {{optional_inline}}
+      - : A string specifying how to round off fractional second digits beyond `fractionalSecondDigits`. See [`Intl.NumberFormat()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/NumberFormat/NumberFormat#roundingmode). Defaults to `"trunc"`.
+    - `smallestUnit` {{optional_inline}}
+      - : A string specifying the smallest unit to include in the output. Possible values are `"minute"`, `"second"`, `"millisecond"`, `"microsecond"`, and `"nanosecond"`, or their plural forms, which (except `"minute"`) are equivalent to `fractionalSecondDigits` values of `0`, `3`, `6`, `9`, respectively. If specified, then `fractionalSecondDigits` is ignored.
+
+### Return value
+
+A string in the [RFC 9557 format](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime#rfc_9557_format) representing this date-time. The calendar annotation is included as specified.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown if any of the options is invalid.
+- {{jsxref("TypeError")}}
+  - : Thrown if `options` is not an object or `undefined`.
+
+## Examples
+
+### Using toString()
+
+```js
+const dt = Temporal.PlainDateTime.from("2021-08-01T12:34:56");
+console.log(dt.toString()); // '2021-08-01T12:34:56'
+```
+
+For examples with rounding times, see {{jsxref("Temporal/PlainTime/toString", "Temporal.PlainTime.prototype.toString()")}}. For examples with displaying calendars, see {{jsxref("Temporal/PlainDate/toString", "Temporal.PlainDate.prototype.toString()")}}.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal/PlainDateTime/from", "Temporal.PlainDateTime.from()")}}
+- {{jsxref("Temporal/PlainDateTime/toJSON", "Temporal.PlainDateTime.prototype.toJSON()")}}
+- {{jsxref("Temporal/PlainDateTime/toLocaleString", "Temporal.PlainDateTime.prototype.toLocaleString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/tozoneddatetime/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/tozoneddatetime/index.md
new file mode 100644
index 000000000000000..a9d6cf8aabda488
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/tozoneddatetime/index.md
@@ -0,0 +1,116 @@
+---
+title: Temporal.PlainDateTime.prototype.toZonedDateTime()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/toZonedDateTime
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.toZonedDateTime
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toZonedDateTime()`** method of {{jsxref("Temporal.PlainDateTime")}} instances returns a new {{jsxref("Temporal.ZonedDateTime")}} instance representing the same date-time as this plain date-time, but in the specified time zone.
+
+## Syntax
+
+```js-nolint
+toZonedDateTime(timeZone)
+toZonedDateTime(timeZone, options)
+```
+
+### Parameters
+
+- `timeZone`
+  - : Either a string or a {{jsxref("Temporal.ZonedDateTime")}} instance representing the time zone to use. If a `Temporal.ZonedDateTime` instance, its time zone is used. If a string, it can be a named time zone identifier, an offset time zone identifier, or a date-time string containing a time zone identifier or an offset (see [time zones and offsets](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#time_zones_and_offsets) for more information).
+- `options` {{optional_inline}}
+  - : An object containing the following property:
+    - `disambiguation` {{optional_inline}}
+      - : A string specifying what to do when this plain time corresponds to zero or more than one instants in the time zone, usually because of daylight saving time shifts. Possible values are `"compatible"`, `"earlier"`, `"later"`, and `"reject"`. Defaults to `"compatible"`. For more information about these values, see [ambiguity and gaps from local time to UTC time](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#ambiguity_and_gaps_from_local_time_to_utc_time).
+
+### Return value
+
+A new {{jsxref("Temporal.ZonedDateTime")}} instance representing the same date-time as this plain date-time, but in the specified time zone.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown if any of the options is invalid, or if `timeZone` is not a valid time zone identifier.
+- {{jsxref("TypeError")}}
+  - : Thrown if any of the arguments are not of the expected type.
+
+## Examples
+
+### Using toZonedDateTime()
+
+```js
+const dt = Temporal.PlainDateTime.from("2021-08-01T12:34:56");
+const zdt = dt.toZonedDateTime("America/New_York");
+console.log(zdt.toString()); // '2021-08-01T12:34:56-04:00[America/New_York]'
+
+const dt2 = Temporal.PlainDateTime.from("2021-01-01T12:34:56");
+const zdt2 = dt2.toZonedDateTime("America/New_York");
+console.log(zdt2.toString()); // '2021-01-01T12:34:56-05:00[America/New_York]'
+```
+
+### Handling ambiguous times
+
+Below, we have two wall-clock times that we want to interpret in the `America/New_York` time zone. The first one, `dtNotExist`, never existed because of a forward daylight saving time shift, so we need to choose from the times `01:05:00-05:00` or `03:05:00-04:00`. The second one, `dtAmbiguous`, appeared twice because of a backward daylight saving time shift, so we need to choose from the times `01:05:00-04:00` or `01:05:00-05:00`. For a more detailed explanation of this situation, see [ambiguity and gaps from local time to UTC time](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#ambiguity_and_gaps_from_local_time_to_utc_time).
+
+```js
+const dtNotExist = Temporal.PlainDateTime.from("2024-03-10T02:05:00");
+const dtAmbiguous = Temporal.PlainDateTime.from("2024-11-03T01:05:00");
+
+// Default: compatible
+console.log(dtNotExist.toZonedDateTime("America/New_York").toString());
+// '2024-03-10T03:05:00-04:00[America/New_York]'
+console.log(dtAmbiguous.toZonedDateTime("America/New_York").toString());
+// '2024-11-03T01:05:00-04:00[America/New_York]'
+
+// Use the earlier time for ambiguous times
+console.log(
+  dtNotExist
+    .toZonedDateTime("America/New_York", { disambiguation: "earlier" })
+    .toString(),
+);
+// '2024-03-10T01:05:00-05:00[America/New_York]'
+console.log(
+  dtAmbiguous
+    .toZonedDateTime("America/New_York", { disambiguation: "earlier" })
+    .toString(),
+);
+// '2024-11-03T01:05:00-04:00[America/New_York]'
+
+// Use the later time for ambiguous times
+console.log(
+  dtNotExist
+    .toZonedDateTime("America/New_York", { disambiguation: "later" })
+    .toString(),
+);
+// '2024-03-10T03:05:00-04:00[America/New_York]'
+console.log(
+  dtAmbiguous
+    .toZonedDateTime("America/New_York", { disambiguation: "later" })
+    .toString(),
+);
+// '2024-11-03T01:05:00-05:00[America/New_York]'
+
+// Throw an error for ambiguous times
+dtNotExist.toZonedDateTime("America/New_York", { disambiguation: "reject" });
+// RangeError: instant is ambiguous
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/PlainDateTime/toPlainDate", "Temporal.PlainDateTime.prototype.toPlainDate()")}}
+- {{jsxref("Temporal/PlainDateTime/toPlainTime", "Temporal.PlainDateTime.prototype.toPlainTime()")}}
+- {{jsxref("Temporal/ZonedDateTime/toPlainDateTime", "Temporal.ZonedDateTime.prototype.toPlainDateTime()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/until/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/until/index.md
new file mode 100644
index 000000000000000..3df46722719efaf
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/until/index.md
@@ -0,0 +1,75 @@
+---
+title: Temporal.PlainDateTime.prototype.until()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/until
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.until
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`until()`** method of {{jsxref("Temporal.PlainDateTime")}} instances returns a new {{jsxref("Temporal.Duration")}} object representing the duration from this date-time to another date-time (in a form convertible by {{jsxref("Temporal/PlainDateTime/from", "Temporal.PlainDateTime.from()")}}). The duration is positive if the other date-time is after this date-time, and negative if before.
+
+This method does `other - this`. To do `this - other`, use the {{jsxref("Temporal/PlainDateTime/since", "since()")}} method.
+
+## Syntax
+
+```js-nolint
+until(other)
+until(other, options)
+```
+
+### Parameters
+
+- `other`
+  - : A string, an object, or a {{jsxref("Temporal.PlainDateTime")}} instance representing a date-time to subtract this date-time from. It is converted to a `Temporal.PlainDateTime` object using the same algorithm as {{jsxref("Temporal/PlainDateTime/from", "Temporal.PlainDateTime.from()")}}. It must have the same calendar as `this`.
+- `options` {{optional_inline}}
+  - : The same options as [`since()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/since#options).
+
+### Return value
+
+A new {{jsxref("Temporal.Duration")}} object representing the duration from this date-time _until_ `other`. The duration is positive if `other` is after this date-time, and negative if before.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown in one of the following cases:
+    - `other` has a different calendar than `this`.
+    - Any of the options is invalid.
+
+## Examples
+
+### Using until()
+
+```js
+let nextBilling = Temporal.PlainDateTime.from({
+  year: Temporal.Now.plainDateISO().year,
+  month: 4,
+  day: 1,
+});
+const now = Temporal.Now.plainDateTimeISO().round("second");
+if (Temporal.PlainDateTime.compare(nextBilling, now) < 0) {
+  nextBilling = nextBilling.add({ years: 1 });
+}
+const duration = now.until(nextBilling);
+console.log(`${duration.toLocaleString("en-US")} until next billing`);
+```
+
+For more examples, see [`since()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/since).
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/PlainDateTime/add", "Temporal.PlainDateTime.prototype.add()")}}
+- {{jsxref("Temporal/PlainDateTime/subtract", "Temporal.PlainDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainDateTime/since", "Temporal.PlainDateTime.prototype.since()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/valueof/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/valueof/index.md
new file mode 100644
index 000000000000000..2abb95db3ae01ee
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/valueof/index.md
@@ -0,0 +1,66 @@
+---
+title: Temporal.PlainDateTime.prototype.valueOf()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/valueOf
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.valueOf
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`valueOf()`** method of {{jsxref("Temporal.PlainDateTime")}} instances throws a {{jsxref("TypeError")}}, which prevents `Temporal.PlainDateTime` instances from being [implicitly converted to primitives](/en-US/docs/Web/JavaScript/Data_structures#primitive_coercion) when used in arithmetic or comparison operations.
+
+## Syntax
+
+```js-nolint
+valueOf()
+```
+
+### Parameters
+
+None.
+
+### Return value
+
+None.
+
+### Exceptions
+
+- {{jsxref("TypeError")}}
+  - : Always thrown.
+
+## Description
+
+Because both [primitive conversion](/en-US/docs/Web/JavaScript/Data_structures#primitive_coercion) and [number conversion](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number#number_coercion) call `valueOf()` before `toString()`, if `valueOf()` is absent, then an expression like `dateTime1 > dateTime2` would implicitly compare them as strings, which may have unexpected results. By throwing a `TypeError`, `Temporal.PlainDateTime` instances prevent such implicit conversions. You need to explicitly convert them to strings using {{jsxref("Temporal/PlainDateTime/toString", "Temporal.PlainDateTime.prototype.toString()")}}, or use the {{jsxref("Temporal/PlainDateTime/compare", "Temporal.PlainDateTime.compare()")}} static method to compare them.
+
+## Examples
+
+### Arithmetic and comparison operations on Temporal.PlainDateTime
+
+All arithmetic and comparison operations on `Temporal.PlainDateTime` instances should use the dedicated methods or convert them to primitives explicitly.
+
+```js
+const dt1 = Temporal.PlainDateTime.from("2022-01-01T00:00:00");
+const dt2 = Temporal.PlainDateTime.from("2022-07-01T00:00:00");
+dt1 > dt2; // TypeError: can't convert PlainDateTime to primitive type
+Temporal.PlainDateTime.compare(dt1, dt2); // -1
+
+dt2 - dt1; // TypeError: can't convert PlainDateTime to primitive type
+dt2.since(dt1).toString(); // "P181D"
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal/PlainDateTime/toString", "Temporal.PlainDateTime.prototype.toString()")}}
+- {{jsxref("Temporal/PlainDateTime/toJSON", "Temporal.PlainDateTime.prototype.toJSON()")}}
+- {{jsxref("Temporal/PlainDateTime/toLocaleString", "Temporal.PlainDateTime.prototype.toLocaleString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/weekofyear/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/weekofyear/index.md
new file mode 100644
index 000000000000000..50315fd64d5444e
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/weekofyear/index.md
@@ -0,0 +1,45 @@
+---
+title: Temporal.PlainDateTime.prototype.weekOfYear
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/weekOfYear
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.weekOfYear
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`weekOfYear`** accessor property of {{jsxref("Temporal.PlainDateTime")}} instances returns a positive integer representing the 1-based week index in the {{jsxref("Temporal/PlainDateTime/yearOfWeek", "yearOfWeek")}} of this date, or `undefined` if the calendar does not have a well-defined week system. The first week of the year is `1`. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+The set accessor of `weekOfYear` is `undefined`. You cannot change this property directly. To create a new `Temporal.PlainDateTime` object with the desired new `weekOfYear` value, use the {{jsxref("Temporal/PlainDateTime/add", "add()")}} or {{jsxref("Temporal/PlainDateTime/subtract", "subtract()")}} method with the appropriate number of `weeks`.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/weekOfYear", "Temporal.PlainDate.prototype.weekOfYear")}}.
+
+## Examples
+
+### Using weekOfYear
+
+```js
+const dt = Temporal.PlainDateTime.from("2021-07-01");
+console.log(dt.weekOfYear); // 26
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal/PlainDateTime/with", "Temporal.PlainDateTime.prototype.with()")}}
+- {{jsxref("Temporal/PlainDateTime/add", "Temporal.PlainDateTime.prototype.add()")}}
+- {{jsxref("Temporal/PlainDateTime/subtract", "Temporal.PlainDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainDateTime/yearOfWeek", "Temporal.PlainDateTime.prototype.yearOfWeek")}}
+- {{jsxref("Temporal/PlainDateTime/dayOfWeek", "Temporal.PlainDateTime.prototype.dayOfWeek")}}
+- {{jsxref("Temporal/PlainDateTime/daysInWeek", "Temporal.PlainDateTime.prototype.daysInWeek")}}
+- {{jsxref("Temporal/PlainDateTime/daysInYear", "Temporal.PlainDateTime.prototype.daysInYear")}}
+- {{jsxref("Temporal/PlainDate/weekOfYear", "Temporal.PlainDate.prototype.weekOfYear")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/with/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/with/index.md
new file mode 100644
index 000000000000000..87a234eb1f05ce0
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/with/index.md
@@ -0,0 +1,83 @@
+---
+title: Temporal.PlainDateTime.prototype.with()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/with
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.with
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`with()`** method of {{jsxref("Temporal.PlainDateTime")}} instances returns a new `Temporal.PlainDateTime` object representing this date-time with some fields replaced by new values. Because all `Temporal` objects are designed to be immutable, this method essentially functions as the setter for the date-time's fields.
+
+To replace the {{jsxref("Temporal/PlainDateTime/calendarId", "calendarId")}} property, use the {{jsxref("Temporal/PlainDateTime/withCalendar", "withCalendar()")}} method instead.
+
+## Syntax
+
+```js-nolint
+with(info)
+with(info, options)
+```
+
+### Parameters
+
+- `info`
+  - : An object containing at least one of the properties recognized by {{jsxref("Temporal/PlainDateTime/from", "Temporal.PlainDateTime.from()")}} (except `calendar`): `day`, `era` and `eraYear`, `hour`, `microsecond`, `millisecond`, `minute`, `month`, `monthCode`, `nanosecond`, `second`, `year`. Unspecified properties use the values from the original date-time. You only need to provide one of `month` or `monthCode`, and one of `era` and `eraYear` or `year`, and the other will be updated accordingly.
+- `options` {{optional_inline}}
+  - : An object containing the following property:
+    - `overflow` {{optional_inline}}
+      - : A string specifying the behavior when a date component is out of range. Possible values are:
+        - `"constrain"` (default)
+          - : The date component is [clamped](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate#invalid_date_clamping) to the valid range.
+        - `"reject"`
+          - : A {{jsxref("RangeError")}} is thrown if the date component is out of range.
+
+### Return value
+
+A new `Temporal.PlainDateTime` object, where the fields specified in `info` that are not `undefined` are replaced by the corresponding values, and the rest of the fields are copied from the original date-time.
+
+### Exceptions
+
+- {{jsxref("TypeError")}}
+  - : Thrown in one of the following cases:
+    - `info` is not an object.
+    - `options` is not an object or `undefined`.
+- {{jsxref("RangeError")}}
+  - : Thrown in one of the following cases:
+    - The provided properties that specify the same component are inconsistent.
+    - The provided non-numerical properties are not valid; for example, if `monthCode` is never a valid month code in this calendar.
+    - The provided numerical properties are out of range, and `options.overflow` is set to `"reject"`.
+
+## Examples
+
+### Using with()
+
+```js
+const dt = Temporal.PlainDateTime.from("2021-07-01T12:34:56");
+const newDT = dt.with({ hour: 13 });
+console.log(newDT.toString()); // "2021-07-01T13:34:56"
+const newDT2 = dt.with({ month: 2, day: 22, millisecond: 222 });
+console.log(newDT2.toString()); // "2021-02-22T13:34:56.222"
+const nextDecade = dt.with({ year: dt.year + 10 });
+console.log(nextDecade.toString()); // "2031-07-01T13:34:56"
+```
+
+For more examples, see the documentation for the individual properties that can be set using `with()`.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal/PlainDateTime/withCalendar", "Temporal.PlainDateTime.prototype.withCalendar()")}}
+- {{jsxref("Temporal/PlainDateTime/withPlainTime", "Temporal.PlainDateTime.prototype.withPlainTime()")}}
+- {{jsxref("Temporal/PlainDateTime/from", "Temporal.PlainDateTime.from()")}}
+- {{jsxref("Temporal/PlainDateTime/add", "Temporal.PlainDateTime.prototype.add()")}}
+- {{jsxref("Temporal/PlainDateTime/subtract", "Temporal.PlainDateTime.prototype.subtract()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/withcalendar/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/withcalendar/index.md
new file mode 100644
index 000000000000000..a465bf9aa5cf70b
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/withcalendar/index.md
@@ -0,0 +1,63 @@
+---
+title: Temporal.PlainDateTime.prototype.withCalendar()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/withCalendar
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.withCalendar
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`withCalendar()`** method of {{jsxref("Temporal.PlainDateTime")}} instances returns a new `Temporal.PlainDateTime` object representing this date-time interpreted in the new calendar system. Because all `Temporal` objects are designed to be immutable, this method essentially functions as the setter for the date-time's {{jsxref("Temporal/PlainDateTime/calendarId", "calendarId")}} property.
+
+To replace the date-time component properties, use the {{jsxref("Temporal/PlainDateTime/with", "with()")}} method instead.
+
+## Syntax
+
+```js-nolint
+withCalendar(calendar)
+```
+
+### Parameters
+
+- `calendar`
+  - : A string that corresponds to the {{jsxref("Temporal/PlainDateTime/calendarId", "calendarId")}} property.
+
+### Return value
+
+A new `Temporal.PlainDateTime` object, representing the date-time specified by the original `PlainDateTime`, interpreted in the new calendar system.
+
+### Exceptions
+
+- {{jsxref("TypeError")}}
+  - : Thrown if `calendar` is not a string.
+- {{jsxref("RangeError")}}
+  - : Thrown if `calendar` is not a valid calendar identifier.
+
+## Examples
+
+### Using withCalendar()
+
+```js
+const dt = Temporal.PlainDateTime.from("2021-07-01T12:34:56");
+const newDT = dt.withCalendar("islamic");
+console.log(newDT.toLocaleString("en-US", { calendar: "islamic" }));
+// 11/21/1442 AH, 12:34:56 PM
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal/PlainDateTime/with", "Temporal.PlainDateTime.prototype.with()")}}
+- {{jsxref("Temporal/PlainDateTime/withPlainTime", "Temporal.PlainDateTime.prototype.withPlainTime()")}}
+- {{jsxref("Temporal/PlainDateTime/from", "Temporal.PlainDateTime.from()")}}
+- {{jsxref("Temporal/PlainDateTime/calendarId", "Temporal.PlainDateTime.prototype.calendarId")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/withplaintime/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/withplaintime/index.md
new file mode 100644
index 000000000000000..1d28eba625468ed
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/withplaintime/index.md
@@ -0,0 +1,67 @@
+---
+title: Temporal.PlainDateTime.prototype.withPlainTime()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/withPlainTime
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.withPlainTime
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`withPlainTime()`** method of {{jsxref("Temporal.PlainDateTime")}} instances returns a new `Temporal.PlainDateTime` object representing this date-time with the time part entirely replaced by the new time (in a form convertible by {{jsxref("Temporal/PlainTime/from", "Temporal.PlainTime.from()")}})
+
+This method will replace all time properties, defaulting to `0` where properties are unspecified. If you only want to replace some of the time properties, use the {{jsxref("Temporal/PlainDateTime/with", "with()")}} method instead.
+
+## Syntax
+
+```js-nolint
+withPlainTime()
+withPlainTime(plainTime)
+```
+
+### Parameters
+
+- `plainTime` {{optional_inline}}
+  - : A string, an object, or a {{jsxref("Temporal.PlainTime")}} instance representing the new time. It is converted to a `Temporal.PlainTime` object using the same algorithm as {{jsxref("Temporal/PlainTime/from", "Temporal.PlainTime.from()")}}. If not specified, the time part is set to `00:00:00`.
+
+### Return value
+
+A new `Temporal.PlainDateTime` object, with the date part copied from the original date-time and the time part replaced by the new time.
+
+## Examples
+
+### Using withPlainTime()
+
+```js
+const dt = Temporal.PlainDateTime.from("2021-07-01T12:34:56");
+
+// You can pass a string
+const newDT = dt.withPlainTime("13:45:00");
+console.log(newDT.toString()); // "2021-07-01T13:45:00"
+
+// You can only specify some time properties, and the rest default to 0;
+// for the with() method, they would be copied from the original date-time
+const newDT2 = dt.withPlainTime({ hour: 13 });
+console.log(newDT2.toString()); // "2021-07-01T13:00:00"
+
+// You can pass nothing to set the time to midnight
+const newDT3 = dt.withPlainTime();
+console.log(newDT3.toString()); // "2021-07-01T00:00:00"
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal/PlainDateTime/with", "Temporal.PlainDateTime.prototype.with()")}}
+- {{jsxref("Temporal/PlainDateTime/withCalendar", "Temporal.PlainDateTime.prototype.withCalendar()")}}
+- {{jsxref("Temporal/PlainDateTime/toPlainTime", "Temporal.PlainDateTime.prototype.toPlainTime()")}}
+- {{jsxref("Temporal/PlainDateTime/from", "Temporal.PlainDateTime.from()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/year/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/year/index.md
new file mode 100644
index 000000000000000..f92f1bde240a311
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/year/index.md
@@ -0,0 +1,46 @@
+---
+title: Temporal.PlainDateTime.prototype.year
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/year
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.year
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`year`** accessor property of {{jsxref("Temporal.PlainDateTime")}} instances returns an integer representing the number of years of this date relative to the start of a calendar-specific epoch year. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+The set accessor of `year` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/PlainDateTime/with", "with()")}} method to create a new `Temporal.PlainDateTime` object with the desired new value.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/year", "Temporal.PlainDate.prototype.year")}}.
+
+## Examples
+
+### Using year
+
+```js
+const dt = Temporal.PlainDateTime.from("2021-07-01"); // ISO 8601 calendar
+console.log(dt.year); // 2021
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal/PlainDateTime/with", "Temporal.PlainDateTime.prototype.with()")}}
+- {{jsxref("Temporal/PlainDateTime/add", "Temporal.PlainDateTime.prototype.add()")}}
+- {{jsxref("Temporal/PlainDateTime/subtract", "Temporal.PlainDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainDateTime/era", "Temporal.PlainDateTime.prototype.era")}}
+- {{jsxref("Temporal/PlainDateTime/eraYear", "Temporal.PlainDateTime.prototype.eraYear")}}
+- {{jsxref("Temporal/PlainDateTime/yearOfWeek", "Temporal.PlainDateTime.prototype.yearOfWeek")}}
+- {{jsxref("Temporal/PlainDateTime/month", "Temporal.PlainDateTime.prototype.month")}}
+- {{jsxref("Temporal/PlainDateTime/day", "Temporal.PlainDateTime.prototype.day")}}
+- {{jsxref("Temporal/PlainDate/year", "Temporal.PlainDate.prototype.year")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/yearofweek/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/yearofweek/index.md
new file mode 100644
index 000000000000000..9ef3a7296b4c0d9
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaindatetime/yearofweek/index.md
@@ -0,0 +1,37 @@
+---
+title: Temporal.PlainDateTime.prototype.yearOfWeek
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime/yearOfWeek
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainDateTime.yearOfWeek
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`yearOfWeek`** accessor property of {{jsxref("Temporal.PlainDateTime")}} instances returns an integer representing the year to be paired with the {{jsxref("Temporal/PlainDateTime/weekOfYear", "weekOfYear")}} of this date, or `undefined` if the calendar does not have a well-defined week system. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+The set accessor of `yearOfWeek` is `undefined`. You cannot change this property directly.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/yearOfWeek", "Temporal.PlainDate.prototype.yearOfWeek")}}.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal/PlainDateTime/with", "Temporal.PlainDateTime.prototype.with()")}}
+- {{jsxref("Temporal/PlainDateTime/add", "Temporal.PlainDateTime.prototype.add()")}}
+- {{jsxref("Temporal/PlainDateTime/subtract", "Temporal.PlainDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainDateTime/year", "Temporal.PlainDateTime.prototype.year")}}
+- {{jsxref("Temporal/PlainDateTime/weekOfYear", "Temporal.PlainDateTime.prototype.weekOfYear")}}
+- {{jsxref("Temporal/PlainDateTime/dayOfWeek", "Temporal.PlainDateTime.prototype.dayOfWeek")}}
+- {{jsxref("Temporal/PlainDateTime/daysInWeek", "Temporal.PlainDateTime.prototype.daysInWeek")}}
+- {{jsxref("Temporal/PlainDateTime/daysInYear", "Temporal.PlainDateTime.prototype.daysInYear")}}
+- {{jsxref("Temporal/PlainDate/yearOfWeek", "Temporal.PlainDate.prototype.yearOfWeek")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plainmonthday/calendarid/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plainmonthday/calendarid/index.md
new file mode 100644
index 000000000000000..145c6473e3dde37
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plainmonthday/calendarid/index.md
@@ -0,0 +1,57 @@
+---
+title: Temporal.PlainMonthDay.prototype.calendarId
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainMonthDay/calendarId
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainMonthDay.calendarId
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`calendarId`** accessor property of {{jsxref("Temporal.PlainMonthDay")}} instances returns a string representing the [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars) used to interpret the internal ISO 8601 date.
+
+For a list of commonly supported values, see {{jsxref("Intl/Locale/getCalendars", "Intl.Locale.prototype.getCalendars()")}}.
+
+The set accessor of `calendarId` is `undefined`. You cannot change this property directly. There's no obvious way to create a new `Temporal.PlainMonthDay` object with a different calendar that represents the same month-day, so you need to convert it to a {{jsxref("Temporal.PlainDate")}} object first using {{jsxref("Temporal/PlainMonthDay/toPlainDate", "toPlainDate()")}}, change the calendar, and then convert it back.
+
+## Examples
+
+### Using calendarId
+
+```js
+const md = Temporal.PlainMonthDay.from("07-01");
+console.log(md.calendarId); // "iso8601"; default
+
+const md2 = Temporal.PlainMonthDay.from("2021-07-01[u-ca=chinese]");
+console.log(md2.calendarId); // "chinese"
+```
+
+### Changing calendarId
+
+```js
+const md = Temporal.PlainMonthDay.from("07-01");
+const newMD = md
+  .toPlainDate({ year: 2021 })
+  .withCalendar("chinese")
+  .toPlainMonthDay();
+console.log(newMD.monthCode, newMD.day); // "M05" 22
+
+const newMD2 = md
+  .toPlainDate({ year: 2022 })
+  .withCalendar("chinese")
+  .toPlainMonthDay();
+console.log(newMD2.monthCode, newMD2.day); // "M06" 3
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainMonthDay")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plainmonthday/day/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plainmonthday/day/index.md
new file mode 100644
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@@ -0,0 +1,81 @@
+---
+title: Temporal.PlainMonthDay.prototype.day
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainMonthDay/day
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainMonthDay.day
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`day`** accessor property of {{jsxref("Temporal.PlainMonthDay")}} instances returns a positive integer representing the 1-based day index in the month of this date, which is the same day number you would see on a calendar. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+The set accessor of `day` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/PlainMonthDay/with", "with()")}} method to create a new `Temporal.PlainMonthDay` object with the desired new value.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/day", "Temporal.PlainDate.prototype.day")}}.
+
+## Examples
+
+### Using day
+
+```js
+const md = Temporal.PlainMonthDay.from("07-01"); // ISO 8601 calendar
+console.log(md.day); // 1
+
+const md2 = Temporal.PlainMonthDay.from("2021-07-01[u-ca=chinese]");
+console.log(md2.day); // 22; it is May 22 in the Chinese calendar
+```
+
+### Changing day
+
+```js
+const md = Temporal.PlainMonthDay.from("07-01");
+const newMD = md.with({ day: 15 });
+console.log(newMD.toString()); // 07-15
+```
+
+By default, `with()` constrains the day to the range of valid values. So you can use `{ day: 1 }` to set the day to the first day of the month, even if the first day does not have the number `1`. Similarly, the following will set the day to the last day of the month:
+
+```js
+const md = Temporal.PlainMonthDay.from("07-01");
+const lastMD = md.with({ day: Number.MAX_VALUE }); // 07-31
+```
+
+For the purpose of `PlainMonthDay`, February is always considered to have 29 days.
+
+```js
+const md = Temporal.PlainMonthDay.from("02-01");
+const lastMD = md.with({ day: Number.MAX_VALUE }); // 02-29
+console.log(lastMD.day); // 29
+```
+
+For other calendars, as long as there exists a year in which the month-day is valid, the month-day is considered valid, and the underlying reference year may therefore change. For example:
+
+```js
+const md = Temporal.PlainMonthDay.from({
+  monthCode: "M02",
+  day: 29,
+  calendar: "hebrew",
+});
+console.log(md.toString()); // 1972-11-06[u-ca=hebrew]
+console.log(md.toLocaleString("en-US", { calendar: "hebrew" })); // 29 Heshvan
+const lastMD = md.with({ day: Number.MAX_VALUE });
+// 30 Heshvan does not exist in 1972, so the reference year changes to 1971
+console.log(lastMD.toString()); // 1971-11-18[u-ca=hebrew]
+console.log(lastMD.toLocaleString("en-US", { calendar: "hebrew" })); // 30 Heshvan
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainMonthDay")}}
+- {{jsxref("Temporal/PlainMonthDay/with", "Temporal.PlainMonthDay.prototype.with()")}}
+- {{jsxref("Temporal/PlainMonthDay/monthCode", "Temporal.PlainMonthDay.prototype.monthCode")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plainmonthday/equals/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plainmonthday/equals/index.md
new file mode 100644
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+---
+title: Temporal.PlainMonthDay.prototype.equals()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainMonthDay/equals
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainMonthDay.equals
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`equals()`** method of {{jsxref("Temporal.PlainMonthDay")}} instances returns `true` if this month-day is equivalent in value to another month-day (in a form convertible by {{jsxref("Temporal/PlainMonthDay/from", "Temporal.PlainMonthDay.from()")}}), and `false` otherwise. They are compared both by their underlying ISO date values and their calendars.
+
+> **Note:** `PlainMonthDay` objects keep track of a reference ISO year, which is also used in the comparison. This year is automatically set when using the {{jsxref("Temporal/PlainMonthDay/from", "Temporal.PlainMonthDay.from()")}} method, but can be set manually using the {{jsxref("Temporal/PlainMonthDay/PlainMonthDay", "Temporal.PlainMonthDay()")}} constructor, causing two equivalent month-days to be considered different if they have different reference years. For this reason, you should avoid using the constructor directly and prefer the `from()` method.
+
+## Syntax
+
+```js-nolint
+equals(other)
+```
+
+### Parameters
+
+- `other`
+  - : A string, an object, or a {{jsxref("Temporal.PlainMonthDay")}} instance representing the other month-day to compare. It is converted to a `Temporal.PlainMonthDay` object using the same algorithm as {{jsxref("Temporal/PlainMonthDay/from", "Temporal.PlainMonthDay.from()")}}.
+
+### Return value
+
+`true` if this month-day is equal to `other` both in their date value and their calendar, `false` otherwise.
+
+## Examples
+
+### Using equals()
+
+```js
+const md1 = Temporal.PlainMonthDay.from("2021-08-01");
+const md2 = Temporal.PlainMonthDay.from({ year: 2020, month: 8, day: 1 }); // Year doesn't matter
+console.log(md1.equals(md2)); // true
+
+const md3 = Temporal.PlainMonthDay.from("2021-08-01[u-ca=japanese]");
+console.log(md1.equals(md3)); // false
+
+const md4 = Temporal.PlainMonthDay.from("2021-08-02");
+console.log(md1.equals(md4)); // false
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainMonthDay")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plainmonthday/from/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plainmonthday/from/index.md
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+---
+title: Temporal.PlainMonthDay.from()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainMonthDay/from
+page-type: javascript-static-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainMonthDay.from
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.PlainMonthDay.from()`** static method creates a new `Temporal.PlainMonthDay` object from another `Temporal.PlainMonthDay` object, an object with month and day properties, or an [RFC 9557](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainMonthDay#rfc_9557_format) string.
+
+## Syntax
+
+```js-nolint
+Temporal.PlainMonthDay.from(info)
+Temporal.PlainMonthDay.from(info, options)
+```
+
+### Parameters
+
+- `info`
+
+  - : One of the following:
+
+    - A {{jsxref("Temporal.PlainMonthDay")}} instance, which creates a copy of the instance.
+    - An [RFC 9557](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainMonthDay#rfc_9557_format) string containing a date and optionally a calendar. If the calendar is not `iso8601`, a year is required.
+    - An object containing the following properties (in the order they are retrieved and validated):
+
+      - `calendar` {{optional_inline}}
+        - : A string that corresponds to the {{jsxref("Temporal/PlainMonthDay/calendarId", "calendarId")}} property. Defaults to `"iso8601"`. All other properties are interpreted in this calendar system (unlike the {{jsxref("Temporal/PlainMonthDay/PlainMonthDay", "Temporal.PlainMonthDay()")}} constructor, which interprets the values in the ISO calendar system).
+      - `day`
+        - : An integer that corresponds to the {{jsxref("Temporal/PlainMonthDay/day", "day")}} property. Must be positive regardless of the `overflow` option.
+      - `era` and `eraYear`
+        - : A string and an integer that can be used instead of `year`. See {{jsxref("Temporal/PlainDate/era", "era")}} and {{jsxref("Temporal/PlainDate/eraYear", "eraYear")}} of `PlainDate`. Are only used if the calendar system has eras. `era` and `eraYear` must be provided simultaneously. If `month` is specified, at least one of `era`+`eraYear` or `year` must be provided. If all of `era`, `eraYear`, and `year` are provided, they must be consistent.
+      - `month`
+        - : A positive integer that can be used instead of `monthCode`. See {{jsxref("Temporal/PlainDate/month", "month")}} of `PlainDate`. Must be positive regardless of the `overflow` option. If `month` is provided, and the calendar is not `iso8601`, then `year` (or `era` + `eraYear` as a substitution) must be provided too, because the same `month` may map to multiple possible `monthCode` values in different years. At least one of `month` or `monthCode` must be provided. If both `month` and `monthCode` are provided, they must be consistent.
+      - `monthCode`
+        - : Corresponds to the {{jsxref("Temporal/PlainMonthDay/monthCode", "monthCode")}} property. At least one of `month` or `monthCode` must be provided. If both `month` and `monthCode` are provided, they must be consistent.
+      - `year`
+        - : An integer used to disambiguate `month` if provided, because for some calendars, the same `month` can mean different `monthCode` in different years. See {{jsxref("Temporal/PlainDate/year", "year")}} of `PlainDate`. If a year is provided, then the `overflow` option validates the month-day in the given year, not just any year. If `month` is specified, at least one of `era`+`eraYear` or `year` must be provided. If all of `era`, `eraYear`, and `year` are provided, they must be consistent.
+
+- `options` {{optional_inline}}
+  - : An object containing the following property:
+    - `overflow` {{optional_inline}}
+      - : A string specifying the behavior when a date component is out of range (when using the object `info`). Possible values are:
+        - `"constrain"` (default)
+          - : The date component is [clamped](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate#invalid_date_clamping) to the valid range.
+        - `"reject"`
+          - : A {{jsxref("RangeError")}} is thrown if the date component is out of range.
+
+### Return value
+
+A new `Temporal.PlainMonthDay` object, representing the month and day specified by `info` in the specified `calendar`.
+
+Each `PlainMonthDay` stores a whole ISO 8601 date internally, which has the same month-day in the target calendar as what's exposed. The reference year is visible when stringifying with {{jsxref("Temporal/PlainMonthDay/toString", "toString()")}}, which outputs an ISO date. The reference year is chosen arbitrarily but consistently (that is, every `(monthCode, day)` pair always maps to the same ISO reference year). It does not use the year provided in the input. Instead, the reference year is chosen by finding the latest date before December 31, 1972 that has the same month-day in the target calendar, or the earliest date after December 31, 1972 if no such date exists.
+
+For example, for Gregorian-derived calendars, the reference year is 1972. For the Hebrew calendar, the reference year is 1972 in the Gregorian calendar, but if the month is Adar I (`M05L`), which is a leap month, the reference year is 1970 (5730 in Hebrew calendar) instead, because the next leap year is 1973 (5733 in Hebrew calendar), which is after 1972.
+
+This reference year canonicalization ensures that {{jsxref("Temporal/PlainMonthDay/equals", "equals()")}} can directly compare the underlying ISO dates without extra computation.
+
+### Exceptions
+
+- {{jsxref("TypeError")}}
+  - : Thrown in one of the following cases:
+    - `info` is not an object or a string.
+    - `options` is not an object or `undefined`.
+    - The provided properties are insufficient to unambiguously determine a date. You usually need to provide a `year` (or `era` and `eraYear`), a `month`, and a `day`, or a `monthCode` and a `day`.
+- {{jsxref("RangeError")}}
+  - : Thrown in one of the following cases:
+    - The provided properties that specify the same component are inconsistent.
+    - The provided non-numerical properties are not valid; for example, if `monthCode` is never a valid month code in this calendar.
+    - The provided numerical properties are out of range, and `options.overflow` is set to `"reject"`.
+
+## Examples
+
+### Creating a PlainMonthDay from an object
+
+```js
+// Month code + day
+const md = Temporal.PlainMonthDay.from({ monthCode: "M05", day: 2 });
+console.log(md.toString()); // 05-02
+
+// Month + day (only for ISO calendar)
+const md2 = Temporal.PlainMonthDay.from({ month: 7, day: 1 });
+console.log(md2.toString()); // 07-01
+
+// Year + month + day
+const md3 = Temporal.PlainMonthDay.from({ year: 2021, month: 7, day: 1 });
+console.log(md3.toString()); // 07-01
+
+// Year + month + day in a different calendar (where year is required)
+const md4 = Temporal.PlainMonthDay.from({
+  year: 2021,
+  month: 7,
+  day: 1,
+  calendar: "hebrew",
+});
+console.log(md4.toString()); // 1972-03-16[u-ca=hebrew]
+
+// Month code + day in a different calendar
+const md5 = Temporal.PlainMonthDay.from({
+  monthCode: "M05L",
+  day: 1,
+  calendar: "hebrew",
+});
+console.log(md5.toString()); // 1970-02-07[u-ca=hebrew]
+```
+
+### Controlling overflow behavior
+
+By default, out-of-range values are clamped to the valid range. A month-day without an explicit reference year is valid as long as there exists one year in which it is valid, even if it doesn't appear every year. If year, month, and day are all given, then the rules for mapping to a valid month-day could be complex and specific to each calendar, but here's the usual behavior:
+
+- If the `year`/`month` combination is invalid, the `month` is clamped to obtain a valid `monthCode` in the year.
+- If the `year`/`monthCode` combination is invalid, a different year is chosen to keep the `monthCode` as-is.
+- The `day` is clamped in the given year-month to obtain a valid month-day.
+
+This is slightly different from usual [date clamping](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate#invalid_date_clamping), which favors the year over the month code.
+
+```js
+// Month always out of range
+const md1 = Temporal.PlainMonthDay.from({ month: 13, day: 1 });
+console.log(md1.toString()); // 12-01
+
+// Month out of range for the specific year: 5732 is not a Hebrew leap year,
+// so month is clamped to 12 to resolve to a valid monthCode
+const md2 = Temporal.PlainMonthDay.from({
+  year: 5732,
+  month: 13,
+  day: 1,
+  calendar: "hebrew",
+});
+console.log(md2.toLocaleString("en-US", { calendar: "hebrew" })); // 1 Elul
+const underlyingDate = Temporal.PlainDate.from(md2.toString());
+console.log(underlyingDate.year, underlyingDate.month); // 5732 12
+
+// Month code exists but not for the specific year: 5731 is not a Hebrew leap year,
+// so a different year is chosen to keep the monthCode as M05L
+const md3 = Temporal.PlainMonthDay.from({
+  year: 5731,
+  monthCode: "M05L",
+  day: 1,
+  calendar: "hebrew",
+});
+console.log(md3.toLocaleString("en-US", { calendar: "hebrew" })); // 1 Adar I
+const underlyingDate2 = Temporal.PlainDate.from(md3.toString());
+console.log(underlyingDate2.year, underlyingDate2.monthCode); // 5730 M05L
+
+// Day always out of range
+const md4 = Temporal.PlainMonthDay.from({ month: 2, day: 30 });
+console.log(md4.toString()); // 02-29
+
+// Day out of range for the specific year-month
+const md5 = Temporal.PlainMonthDay.from({ year: 2021, month: 2, day: 29 });
+console.log(md5.toString()); // 02-28
+```
+
+You can change this behavior to throw an error instead:
+
+```js
+Temporal.PlainMonthDay.from(
+  { year: 2021, month: 13, day: 1 },
+  { overflow: "reject" },
+);
+// RangeError: date value "month" not in 1..12: 13
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainMonthDay")}}
+- {{jsxref("Temporal/PlainMonthDay/PlainMonthDay", "Temporal.PlainMonthDay()")}}
+- {{jsxref("Temporal/PlainMonthDay/with", "Temporal.PlainMonthDay.prototype.with()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plainmonthday/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plainmonthday/index.md
new file mode 100644
index 000000000000000..766ce3aa4f28f06
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plainmonthday/index.md
@@ -0,0 +1,114 @@
+---
+title: Temporal.PlainMonthDay
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainMonthDay
+page-type: javascript-class
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainMonthDay
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.PlainMonthDay`** object represents the month and day of a calendar date, without a year or time zone; for example, an event on a calendar that recurs every year and happens during the whole day. It is fundamentally represented as an ISO 8601 calendar date, with year, month, and day fields, and an associated calendar system. The year is used to disambiguate the month-day in non-ISO calendar systems.
+
+## Description
+
+A `PlainMonthDay` is essentially the month-day part of a {{jsxref("Temporal.PlainDate")}} object, without the year. Because the meaning of a month-day can change from year to year (for example, whether it exists, or what the month-day of the next day is), this object doesn't provide much functionality on its own, such as comparison, addition, or subtraction. It doesn't even have a {{jsxref("Temporal/PlainDate/month", "month")}} property, because the month index is not meaningful without a year (for example, two months from two years with the same index can have different names in the case of leap months).
+
+### RFC 9557 format
+
+`PlainMonthDay` objects can be serialized and parsed using the [RFC 9557](https://datatracker.ietf.org/doc/html/rfc9557) format, an extension to the [ISO 8601 / RFC 3339](https://datatracker.ietf.org/doc/html/rfc3339) format. The string has the following form (spaces are only for readability and should not be present in the actual string):
+
+```plain
+YYYY-MM-DD [u-ca=calendar_id]
+```
+
+- `YYYY` {{optional_inline}}
+  - : Either a four-digit number, or a six-digit number with a `+` or `-` sign. It is required for non-ISO calendars, and optional otherwise. If omitted, you can either replace `YYYY-` with `--` (so the string looks like `--MM-DD` or `--MMDD`), or omit the `YYYY-` part entirely (so the string looks like `MM-DD` or `MMDD`). Note that the reference year actually stored may be different from the one you provide, but the represented month-day is the same. See {{jsxref("Temporal/PlainMonthDay/from", "Temporal.PlainMonthDay.from()")}} for more information.
+- `MM`
+  - : A two-digit number from `01` to `12`.
+- `DD`
+  - : A two-digit number from `01` to `31`. The `YYYY`, `MM`, and `DD` components can be separated by `-` or nothing.
+- `[u-ca=calendar_id]` {{optional_inline}}
+  - : Replace `calendar_id` with the calendar to use. May have a _critical flag_ by prefixing the key with `!`: e.g., `[!u-ca=iso8601]`. This flag generally tells other systems that it cannot be ignored if they don't support it. The `Temporal` parser will throw an error if the annotations contain two or more calendar annotations and one of them is critical. Defaults to `[u-ca=iso8601]`. Note that the `YYYY-MM-DD` is always interpreted as an ISO 8601 calendar date and then converted to the specified calendar.
+
+As an input, you may optionally include the time, offset, and time zone identifier, in the same format as [`PlainDateTime`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime#rfc_9557_format), but they will be ignored. Other annotations in the `[key=value]` format are also ignored, and they must not have the critical flag.
+
+When serializing, you can configure whether to display the calendar ID, and whether to add a critical flag for it.
+
+## Constructor
+
+- {{jsxref("Temporal/PlainMonthDay/PlainMonthDay", "Temporal.PlainMonthDay()")}} {{experimental_inline}}
+  - : Creates a new `Temporal.PlainMonthDay` object by directly supplying the underlying data.
+
+## Static methods
+
+- {{jsxref("Temporal/PlainMonthDay/from", "Temporal.PlainMonthDay.from()")}} {{experimental_inline}}
+  - : Creates a new `Temporal.PlainMonthDay` object from another `Temporal.PlainMonthDay` object, an object with month and day properties, or an [RFC 9557](#rfc_9557_format) string.
+
+## Instance properties
+
+These properties are defined on `Temporal.PlainMonthDay.prototype` and shared by all `Temporal.PlainMonthDay` instances.
+
+- {{jsxref("Temporal/PlainMonthDay/calendarId", "Temporal.PlainMonthDay.prototype.calendarId")}} {{experimental_inline}}
+  - : Returns a string representing the [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars) used to interpret the internal ISO 8601 date.
+- {{jsxref("Object/constructor", "Temporal.PlainMonthDay.prototype.constructor")}}
+  - : The constructor function that created the instance object. For `Temporal.PlainMonthDay` instances, the initial value is the {{jsxref("Temporal/PlainMonthDay/PlainMonthDay", "Temporal.PlainMonthDay()")}} constructor.
+- {{jsxref("Temporal/PlainMonthDay/day", "Temporal.PlainMonthDay.prototype.day")}} {{experimental_inline}}
+  - : Returns a positive integer representing the 1-based day index in the month of this date, which is the same day number you would see on a calendar. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. Generally starts at 1 and is continuous, but not always.
+- {{jsxref("Temporal/PlainMonthDay/monthCode", "Temporal.PlainMonthDay.prototype.monthCode")}} {{experimental_inline}}
+  - : Returns a calendar-specific string representing the month of this date. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. Usually it is `M` plus a two-digit month number. For leap months, it is the previous month's code followed by `L`. If the leap month is the first month of the year, the code is `M00L`.
+- `Temporal.PlainMonthDay.prototype[Symbol.toStringTag]`
+  - : The initial value of the [`[Symbol.toStringTag]`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol/toStringTag) property is the string `"Temporal.PlainMonthDay"`. This property is used in {{jsxref("Object.prototype.toString()")}}.
+
+## Instance methods
+
+- {{jsxref("Temporal/PlainMonthDay/equals", "Temporal.PlainMonthDay.prototype.equals()")}} {{experimental_inline}}
+  - : Returns `true` if this month-day is equivalent in value to another month-day (in a form convertible by {{jsxref("Temporal/PlainMonthDay/from", "Temporal.PlainMonthDay.from()")}}), and `false` otherwise. They are compared both by their date values and their calendars.
+- {{jsxref("Temporal/PlainMonthDay/toJSON", "Temporal.PlainMonthDay.prototype.toJSON()")}} {{experimental_inline}}
+  - : Returns a string representing this month-day in the same [RFC 9557 format](#rfc_9557_format) as calling {{jsxref("Temporal/PlainMonthDay/toString", "toString()")}}. Intended to be implicitly called by {{jsxref("JSON.stringify()")}}.
+- {{jsxref("Temporal/PlainMonthDay/toLocaleString", "Temporal.PlainMonthDay.prototype.toLocaleString()")}} {{experimental_inline}}
+  - : Returns a string with a language-sensitive representation of this month-day.
+- {{jsxref("Temporal/PlainMonthDay/toPlainDate", "Temporal.PlainMonthDay.prototype.toPlainDate()")}} {{experimental_inline}}
+  - : Returns a new {{jsxref("Temporal.PlainDate")}} object representing this month-day and a supplied year in the same calendar system.
+- {{jsxref("Temporal/PlainMonthDay/toString", "Temporal.PlainMonthDay.prototype.toString()")}} {{experimental_inline}}
+  - : Returns a string representing this month-day in the [RFC 9557 format](#rfc_9557_format).
+- {{jsxref("Temporal/PlainMonthDay/valueOf", "Temporal.PlainMonthDay.prototype.valueOf()")}} {{experimental_inline}}
+  - : Throws a {{jsxref("TypeError")}}, which prevents `Temporal.PlainMonthDay` instances from being [implicitly converted to primitives](/en-US/docs/Web/JavaScript/Data_structures#primitive_coercion) when used in arithmetic or comparison operations.
+- {{jsxref("Temporal/PlainMonthDay/with", "Temporal.PlainMonthDay.prototype.with()")}} {{experimental_inline}}
+  - : Returns a new `Temporal.PlainMonthDay` object representing this month-day with some fields replaced by new values.
+
+## Examples
+
+### Getting the next occurrence of a festival
+
+```js
+// Chinese New Years are on 1/1 in the Chinese calendar
+const chineseNewYear = Temporal.PlainMonthDay.from({
+  monthCode: "M01",
+  day: 1,
+  calendar: "chinese",
+});
+const currentYear = Temporal.Now.plainDateISO().withCalendar("chinese").year;
+let nextCNY = chineseNewYear.toPlainDate({ year: currentYear });
+if (Temporal.PlainDate.compare(nextCNY, Temporal.Now.plainDateISO()) <= 0) {
+  nextCNY = nextCNY.add({ years: 1 });
+}
+console.log(
+  `The next Chinese New Year is on ${nextCNY.withCalendar("iso8601").toLocaleString()}`,
+);
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal")}}
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal.PlainYearMonth")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plainmonthday/monthcode/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plainmonthday/monthcode/index.md
new file mode 100644
index 000000000000000..6464524d51c3126
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plainmonthday/monthcode/index.md
@@ -0,0 +1,73 @@
+---
+title: Temporal.PlainMonthDay.prototype.monthCode
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainMonthDay/monthCode
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainMonthDay.monthCode
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`monthCode`** accessor property of {{jsxref("Temporal.PlainMonthDay")}} instances returns a calendar-specific string representing the month of this date. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+Usually it is `M` plus a two-digit month number. For leap months, it is the previous month's code followed by `L` (even if it's conceptually a derivative of the following month; for example, in the Hebrew calendar, Adar I has code `M05L` but Adar II has code `M06`). If the leap month is the first month of the year, the code is `M00L`.
+
+Because {{jsxref("Temporal/PlainDate/month", "month")}} is an index within a year, but `PlainMonthDay` doesn't have a year, there's no `month` property for `PlainMonthDay`. Therefore, `monthCode` is used to represent the month in a way that is independent of the year.
+
+The set accessor of `monthCode` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/PlainMonthDay/with", "with()")}} method to create a new `Temporal.PlainMonthDay` object with the desired new value.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/monthCode", "Temporal.PlainDate.prototype.monthCode")}}.
+
+## Examples
+
+### Using monthCode
+
+```js
+const md = Temporal.PlainMonthDay.from("07-01"); // ISO 8601 calendar
+console.log(md.monthCode); // "M07"
+
+const md2 = Temporal.PlainMonthDay.from("2021-05-01[u-ca=chinese]");
+console.log(md2.monthCode); // "M03"
+
+const md3 = Temporal.PlainMonthDay.from("2023-04-01[u-ca=chinese]");
+console.log(md3.monthCode); // "M02L"
+```
+
+### Changing monthCode
+
+```js
+const md = Temporal.PlainMonthDay.from("07-01");
+const newMD = md.with({ monthCode: "M03" });
+console.log(newMD.toString()); // 03-01
+```
+
+For other calendars, as long as there exists a year in which the month-day is valid, the month-day is considered valid, and the underlying reference year may therefore change. For example:
+
+```js
+const md = Temporal.PlainMonthDay.from({
+  monthCode: "M02",
+  day: 30,
+  calendar: "hebrew",
+});
+console.log(md.toString()); // 1971-11-18[u-ca=hebrew]
+console.log(md.toLocaleString("en-US", { calendar: "hebrew" })); // 30 Heshvan
+// 30 Heshvan only exists in 1971, but this year is not a leap year
+const newMD = md.with({ monthCode: "M05L" });
+console.log(newMD.toString()); // 1970-03-08[u-ca=hebrew]
+console.log(newMD.toLocaleString("en-US", { calendar: "hebrew" })); // 30 Adar I
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainMonthDay")}}
+- {{jsxref("Temporal/PlainMonthDay/with", "Temporal.PlainMonthDay.prototype.with()")}}
+- {{jsxref("Temporal/PlainMonthDay/day", "Temporal.PlainMonthDay.prototype.day")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plainmonthday/plainmonthday/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plainmonthday/plainmonthday/index.md
new file mode 100644
index 000000000000000..dc75c765922bdd1
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plainmonthday/plainmonthday/index.md
@@ -0,0 +1,91 @@
+---
+title: Temporal.PlainMonthDay()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainMonthDay/PlainMonthDay
+page-type: javascript-constructor
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainMonthDay.PlainMonthDay
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.PlainMonthDay()`** constructor creates {{jsxref("Temporal.PlainMonthDay")}} objects.
+
+This constructor allows you to create instances by directly supplying the underlying data. Like all other `Temporal` classes, you should usually construct `Temporal.PlainMonthDay` objects using the {{jsxref("Temporal/PlainMonthDay/from", "Temporal.PlainMonthDay.from()")}} static method, which can handle a variety of input types.
+
+## Syntax
+
+```js-nolint
+new Temporal.PlainMonthDay(month, day)
+new Temporal.PlainMonthDay(month, day, calendar)
+new Temporal.PlainMonthDay(month, day, calendar, referenceYear)
+```
+
+> **Note:** `Temporal.PlainMonthDay()` can only be constructed with [`new`](/en-US/docs/Web/JavaScript/Reference/Operators/new). Attempting to call it without `new` throws a {{jsxref("TypeError")}}.
+
+> [!WARNING]
+> Avoid using the `calendar` and `referenceYear` parameters, because {{jsxref("Temporal/PlainMonthDay/equals", "equals()")}} will consider the reference year for equality, causing two equivalent month-days to be considered different if they have different reference years. To create a `Temporal.PlainMonthDay` object with a non-ISO calendar, use the {{jsxref("Temporal/PlainMonthDay/from", "Temporal.PlainMonthDay.from()")}} static method.
+
+### Parameters
+
+- `month`
+  - : A number, truncated to an integer, representing the month in the ISO calendar system.
+- `day`
+  - : A number, truncated to an integer, representing the day of the month in the ISO calendar system.
+- `calendar` {{optional_inline}}
+  - : A string representing the [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars) to use. Note that irrespective of the `calendar`, the `referenceYear`, `month`, and `day` must be in the ISO 8601 calendar system. Defaults to `"iso8601"`.
+- `referenceYear` {{optional_inline}}
+  - : A number, truncated to an integer, representing the year in the ISO calendar system. Defaults to `1972`. The same ISO month-day can represent different dates in different years with non-ISO calendars. For example, the days 2021-07-01 and 1972-07-01 may fall on different month-days in a non-Gregorian calendar, and just specifying "07-01" is insufficient to unambiguously determine a month-day in the target calendar. Therefore, you virtually always want to specify a `referenceYear` when using a non-ISO calendar.
+
+### Return value
+
+A new `Temporal.PlainMonthDay` object, representing the month-day of the date specified by `referenceYear`, `month`, `day` (in the ISO calendar), interpreted in the calendar system specified by `calendar`.
+
+### Exceptions
+
+- {{jsxref("TypeError")}}
+  - : Thrown if `calendar` is not a string or `undefined`.
+- {{jsxref("RangeError")}}
+  - : Thrown in one of the following cases:
+    - `referenceYear`, `month`, or `day` is not a finite number, or do not represent a valid date in the ISO calendar system.
+    - `calendar` is not a valid calendar identifier.
+
+## Examples
+
+### Using Temporal.PlainMonthDay()
+
+```js
+const md = new Temporal.PlainMonthDay(7, 1);
+console.log(md.toString()); // 07-01
+
+const md2 = new Temporal.PlainMonthDay(7, 1, "chinese");
+console.log(md2.toString()); // 1972-07-01[u-ca=chinese]
+
+const md3 = new Temporal.PlainMonthDay(7, 1, "chinese", 2021);
+console.log(md3.toString()); // 2021-07-01[u-ca=chinese]
+```
+
+### Improper usage
+
+You should avoid using the `calendar` and `referenceYear` parameters, unless you know that the `referenceYear` is the canonical reference year that would be selected by `Temporal.PlainMonthDay.from()` for the same month-day.
+
+```js
+const md = new Temporal.PlainMonthDay(7, 1, "chinese", 2021);
+const md2 = Temporal.PlainMonthDay.from("2021-07-01[u-ca=chinese]");
+console.log(md.equals(md2)); // false
+console.log(md.toString()); // 2021-07-01[u-ca=chinese]
+console.log(md2.toString()); // 1972-07-02[u-ca=chinese]
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainMonthDay")}}
+- {{jsxref("Temporal/PlainMonthDay/from", "Temporal.PlainMonthDay.from()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plainmonthday/tojson/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plainmonthday/tojson/index.md
new file mode 100644
index 000000000000000..916054120d51a87
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plainmonthday/tojson/index.md
@@ -0,0 +1,70 @@
+---
+title: Temporal.PlainMonthDay.prototype.toJSON()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainMonthDay/toJSON
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainMonthDay.toJSON
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toJSON()`** method of {{jsxref("Temporal.PlainMonthDay")}} instances returns a string representing this month-day in the same [RFC 9557 format](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainMonthDay#rfc_9557_format) as calling {{jsxref("Temporal/PlainMonthDay/toString", "toString()")}}. It is intended to be implicitly called by {{jsxref("JSON.stringify()")}}.
+
+## Syntax
+
+```js-nolint
+toJSON()
+```
+
+### Parameters
+
+None.
+
+### Return value
+
+A string representing the given month-day in the [RFC 9557 format](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainMonthDay#rfc_9557_format), with the year and calendar annotation included if it is not `"iso8601"`.
+
+## Description
+
+The `toJSON()` method is automatically called by {{jsxref("JSON.stringify()")}} when a `Temporal.PlainMonthDay` object is stringified. This method is generally intended to, by default, usefully serialize `Temporal.PlainMonthDay` objects during [JSON](/en-US/docs/Glossary/JSON) serialization, which can then be deserialized using the {{jsxref("Temporal/PlainMonthDay/from", "Temporal.PlainMonthDay.from()")}} function as the reviver of {{jsxref("JSON.parse()")}}.
+
+## Examples
+
+### Using toJSON()
+
+```js
+const md = Temporal.PlainMonthDay.from({ month: 8, day: 1 });
+const mdStr = md.toJSON(); // '08-01'
+const md2 = Temporal.PlainMonthDay.from(mdStr);
+```
+
+### JSON serialization and parsing
+
+This example shows how `Temporal.PlainMonthDay` can be serialized as JSON without extra effort, and how to parse it back.
+
+```js
+const md = Temporal.PlainMonthDay.from({ month: 8, day: 1 });
+const jsonStr = JSON.stringify({ birthday: md }); // '{"birthday":"08-01"}'
+const obj = JSON.parse(jsonStr, (key, value) => {
+  if (key === "birthday") {
+    return Temporal.PlainMonthDay.from(value);
+  }
+  return value;
+});
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainMonthDay")}}
+- {{jsxref("Temporal/PlainMonthDay/from", "Temporal.PlainMonthDay.from()")}}
+- {{jsxref("Temporal/PlainMonthDay/toString", "Temporal.PlainMonthDay.prototype.toString()")}}
+- {{jsxref("Temporal/PlainMonthDay/toLocaleString", "Temporal.PlainMonthDay.prototype.toLocaleString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plainmonthday/tolocalestring/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plainmonthday/tolocalestring/index.md
new file mode 100644
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--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plainmonthday/tolocalestring/index.md
@@ -0,0 +1,103 @@
+---
+title: Temporal.PlainMonthDay.prototype.toLocaleString()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainMonthDay/toLocaleString
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainMonthDay.toLocaleString
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toLocaleString()`** method of {{jsxref("Temporal.PlainMonthDay")}} instances returns a string with a language-sensitive representation of this month-day. In implementations with [`Intl.DateTimeFormat` API](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat) support, this method delegates to `Intl.DateTimeFormat`.
+
+Every time `toLocaleString` is called, it has to perform a search in a big database of localization strings, which is potentially inefficient. When the method is called many times with the same arguments, it is better to create a {{jsxref("Intl.DateTimeFormat")}} object and use its {{jsxref("Intl/DateTimeFormat/format", "format()")}} method, because a `DateTimeFormat` object remembers the arguments passed to it and may decide to cache a slice of the database, so future `format` calls can search for localization strings within a more constrained context.
+
+## Syntax
+
+```js-nolint
+toLocaleString()
+toLocaleString(locales)
+toLocaleString(locales, options)
+```
+
+### Parameters
+
+The `locales` and `options` parameters customize the behavior of the function and let applications specify the language whose formatting conventions should be used.
+
+In implementations that support the [`Intl.DateTimeFormat` API](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat), these parameters correspond exactly to the [`Intl.DateTimeFormat()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat/DateTimeFormat) constructor's parameters. Implementations without `Intl.DateTimeFormat` support return the exact same string as {{jsxref("Temporal/PlainMonthDay/toString", "toString()")}}, ignoring both parameters.
+
+- `locales` {{optional_inline}}
+  - : A string with a BCP 47 language tag, or an array of such strings. Corresponds to the [`locales`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat/DateTimeFormat#locales) parameter of the `Intl.DateTimeFormat()` constructor.
+- `options` {{optional_inline}}
+
+  - : An object adjusting the output format. Corresponds to the [`options`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat/DateTimeFormat#options) parameter of the `Intl.DateTimeFormat()` constructor. The `calendar` option must be provided with the same value as this month-day's calendar. Regarding the [date-time component options](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat/DateTimeFormat#date-time_component_options) and the style shortcuts (`dateStyle` and `timeStyle`), the options should follow one of these forms:
+
+    - Provide none of them: `month` and `day` will default to `"numeric"`.
+    - Provide `dateStyle` only: it expands to `month` and `day` formats.
+    - Provide some date-time component options, where at least one of them is `month` or `day`. Only the specified date components will be included in the output.
+
+See the [`Intl.DateTimeFormat()` constructor](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat/DateTimeFormat) for details on these parameters and how to use them.
+
+### Return value
+
+A string representing the given month-day according to language-specific conventions.
+
+In implementations with `Intl.DateTimeFormat`, this is equivalent to `new Intl.DateTimeFormat(locales, options).format(monthDay)`, where `options` has been normalized as described above.
+
+> [!NOTE]
+> Most of the time, the formatting returned by `toLocaleString()` is consistent. However, the output may vary between implementations, even within the same locale — output variations are by design and allowed by the specification. It may also not be what you expect. For example, the string may use non-breaking spaces or be surrounded by bidirectional control characters. You should not compare the results of `toLocaleString()` to hardcoded constants.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown if any of the options is invalid.
+- {{jsxref("TypeError")}}
+  - : Thrown if any of the options is not of the expected type.
+
+## Examples
+
+### Using toLocaleString()
+
+Basic use of this method without specifying a `locale` returns a formatted string in the default locale and with default options.
+
+```js
+// Note that just specifying "08-01" defaults to the ISO 8601 calendar,
+// which throws an error if the locale's default calendar is not ISO 8601.
+const md = Temporal.PlainMonthDay.from("2021-08-01[u-ca=gregory]");
+
+console.log(md.toLocaleString()); // 8/1 (assuming en-US locale and Gregorian calendar)
+```
+
+If the month-day's calendar doesn't match the locale's default calendar, even when its calendar is `iso8601`, an explicit `calendar` option must be provided with the same value.
+
+```js
+const md = Temporal.PlainMonthDay.from("08-01");
+md.toLocaleString("en-US", { calendar: "iso8601" }); // 08-01
+```
+
+### Using toLocaleString() with options
+
+You can customize which parts of the month-day are included in the output by providing the `options` parameter.
+
+```js
+const md = Temporal.PlainMonthDay.from("2021-08-01[u-ca=gregory]");
+md.toLocaleString("en-US", { dateStyle: "full" }); // August 1
+md.toLocaleString("en-US", { month: "long" }); // August
+md.toLocaleString("en-US", { day: "numeric" }); // 1
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainMonthDay")}}
+- {{jsxref("Intl.DateTimeFormat")}}
+- {{jsxref("Temporal/PlainMonthDay/toJSON", "Temporal.PlainMonthDay.prototype.toJSON()")}}
+- {{jsxref("Temporal/PlainMonthDay/toString", "Temporal.PlainMonthDay.prototype.toString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plainmonthday/toplaindate/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plainmonthday/toplaindate/index.md
new file mode 100644
index 000000000000000..9a205da8c06f445
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plainmonthday/toplaindate/index.md
@@ -0,0 +1,66 @@
+---
+title: Temporal.PlainMonthDay.prototype.toPlainDate()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainMonthDay/toPlainDate
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainMonthDay.toPlainDate
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toPlainDate()`** method of {{jsxref("Temporal.PlainMonthDay")}} instances returns a new {{jsxref("Temporal.PlainDate")}} object representing this month-day and a supplied year in the same calendar system.
+
+## Syntax
+
+```js-nolint
+toPlainDate(yearInfo)
+```
+
+### Parameters
+
+- `yearInfo`
+  - : An object representing the year component of the resulting `PlainDate`, containing the following properties (in the order they are retrieved and validated):
+    - `era` and `eraYear`
+      - : A string and an integer that correspond to the {{jsxref("Temporal/PlainDate/era", "era")}} and {{jsxref("Temporal/PlainDate/eraYear", "eraYear")}} properties. Are only used if the calendar system has eras. `era` and `eraYear` must be provided simultaneously. If they are not provided, then `year` must be provided. If all of `era`, `eraYear`, and `year` are provided, they must be consistent.
+    - `year`
+      - : Corresponds to the {{jsxref("Temporal/PlainDate/year", "year")}} property.
+
+### Return value
+
+A new `Temporal.PlainDate` object representing the date specified by this month-day and the year in `yearInfo`, interpreted in the calendar system of this month-day.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown if any of the options is invalid.
+- {{jsxref("TypeError")}}
+  - : Thrown if `yearInfo` is not an object.
+
+## Examples
+
+### Using toPlainDate()
+
+```js
+const md = Temporal.PlainMonthDay.from("07-01");
+const date = md.toPlainDate({ year: 2021 });
+console.log(date.toString()); // 2021-07-01
+
+const md2 = Temporal.PlainMonthDay.from("2021-07-01[u-ca=japanese]");
+const date2 = md2.toPlainDate({ era: "reiwa", eraYear: 1 });
+console.log(date2.toString()); // 2019-07-01[u-ca=japanese]
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainMonthDay")}}
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal/PlainDate/toPlainMonthDay", "Temporal.PlainDate.prototype.toPlainMonthDay()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plainmonthday/tostring/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plainmonthday/tostring/index.md
new file mode 100644
index 000000000000000..6f70dec3e878aa0
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plainmonthday/tostring/index.md
@@ -0,0 +1,95 @@
+---
+title: Temporal.PlainMonthDay.prototype.toString()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainMonthDay/toString
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainMonthDay.toString
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toString()`** method of {{jsxref("Temporal.PlainMonthDay")}} instances returns a string representing this month-day in the [RFC 9557 format](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainMonthDay#rfc_9557_format).
+
+## Syntax
+
+```js-nolint
+toString()
+toString(options)
+```
+
+### Parameters
+
+- `options` {{optional_inline}}
+  - : An object containing the following property:
+    - `calendarName` {{optional_inline}}
+      - : Whether to show the calendar annotation (`[u-ca=calendar_id]`) in the return value. Possible values are:
+        - `"auto"` (default)
+          - : Include the calendar annotation if the calendar is not `"iso8601"`. The reference year is included if the calendar is not `"iso8601"`.
+        - `"always"`
+          - : Always include the calendar annotation. The reference year is always included too.
+        - `"never"`
+          - : Never include the calendar annotation. This makes the returned string not recoverable to the same {{jsxref("Temporal.PlainMonthDay")}} instance, although the month-day value still remains the same. The reference year is included if the calendar is not `"iso8601"`.
+        - `"critical"`
+          - : Always include the calendar annotation, and add a critical flag: `[!u-ca=calendar_id]`. Useful when sending the string to certain systems, but not useful for Temporal itself. The reference year is always included too.
+
+### Return value
+
+A string in the [RFC 9557 format](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainMonthDay#rfc_9557_format) representing this month-day. The calendar annotation is included as specified. The reference year is included if a calendar annotation is included or if the calendar is not `"iso8601"`.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown if any of the options is invalid.
+- {{jsxref("TypeError")}}
+  - : Thrown if `options` is not an object or `undefined`.
+
+## Examples
+
+### Using toString()
+
+```js
+const md = Temporal.PlainMonthDay.from({ month: 8, day: 1 });
+console.log(md.toString()); // '08-01'
+
+const md2 = Temporal.PlainMonthDay.from({
+  monthCode: "M08",
+  day: 1,
+  calendar: "chinese",
+});
+console.log(md2.toString()); // '1972-09-08[u-ca=chinese]'
+```
+
+### Using options
+
+```js
+const isoMD = Temporal.PlainMonthDay.from({ month: 8, day: 1 });
+const md = Temporal.PlainMonthDay.from({
+  monthCode: "M08",
+  day: 1,
+  calendar: "chinese",
+});
+console.log(isoMD.toString({ calendarName: "auto" })); // '08-01'
+console.log(md.toString({ calendarName: "auto" })); // '1972-09-08[u-ca=chinese]'
+console.log(isoMD.toString({ calendarName: "always" })); // '1972-08-01[u-ca=iso8601]'
+console.log(md.toString({ calendarName: "always" })); // '1972-09-08[u-ca=chinese]'
+console.log(isoMD.toString({ calendarName: "never" })); // '08-01'
+console.log(md.toString({ calendarName: "never" })); // '1972-09-08'
+console.log(isoMD.toString({ calendarName: "critical" })); // '1972-08-01[!u-ca=iso8601]'
+console.log(md.toString({ calendarName: "critical" })); // '1972-09-08[!u-ca=chinese]'
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainMonthDay")}}
+- {{jsxref("Temporal/PlainMonthDay/from", "Temporal.PlainMonthDay.from()")}}
+- {{jsxref("Temporal/PlainMonthDay/toJSON", "Temporal.PlainMonthDay.prototype.toJSON()")}}
+- {{jsxref("Temporal/PlainMonthDay/toLocaleString", "Temporal.PlainMonthDay.prototype.toLocaleString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plainmonthday/valueof/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plainmonthday/valueof/index.md
new file mode 100644
index 000000000000000..791348b6c22c50e
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plainmonthday/valueof/index.md
@@ -0,0 +1,72 @@
+---
+title: Temporal.PlainMonthDay.prototype.valueOf()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainMonthDay/valueOf
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainMonthDay.valueOf
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`valueOf()`** method of {{jsxref("Temporal.PlainMonthDay")}} instances throws a {{jsxref("TypeError")}}, which prevents `Temporal.PlainMonthDay` instances from being [implicitly converted to primitives](/en-US/docs/Web/JavaScript/Data_structures#primitive_coercion) when used in arithmetic or comparison operations.
+
+## Syntax
+
+```js-nolint
+valueOf()
+```
+
+### Parameters
+
+None.
+
+### Return value
+
+None.
+
+### Exceptions
+
+- {{jsxref("TypeError")}}
+  - : Always thrown.
+
+## Description
+
+Because both [primitive conversion](/en-US/docs/Web/JavaScript/Data_structures#primitive_coercion) and [number conversion](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number#number_coercion) call `valueOf()` before `toString()`, if `valueOf()` is absent, then an expression like `monthDay1 > monthDay2` would implicitly compare them as strings, which may have unexpected results. By throwing a `TypeError`, `Temporal.PlainMonthDay` instances prevent such implicit conversions. You need to explicitly convert them to strings using {{jsxref("Temporal/PlainMonthDay/toString", "Temporal.PlainMonthDay.prototype.toString()")}}.
+
+## Examples
+
+### Arithmetic and comparison operations on Temporal.PlainMonthDay
+
+All arithmetic and comparison operations on `Temporal.PlainMonthDay` instances should use the dedicated methods or convert them to primitives explicitly.
+
+```js
+const md1 = Temporal.PlainMonthDay.from("01-01");
+const md2 = Temporal.PlainMonthDay.from("07-01");
+md1 > md2; // TypeError: can't convert PlainMonthDay to primitive type
+Temporal.PlainDate.compare(
+  md1.toPlainDate({ year: 2021 }),
+  md2.toPlainDate({ year: 2021 }),
+); // -1
+
+md2 - md1; // TypeError: can't convert PlainMonthDay to primitive type
+md2
+  .toPlainDate({ year: 2021 })
+  .since(md1.toPlainDate({ year: 2021 }))
+  .toString(); // "P181D"
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainMonthDay")}}
+- {{jsxref("Temporal/PlainMonthDay/toString", "Temporal.PlainMonthDay.prototype.toString()")}}
+- {{jsxref("Temporal/PlainMonthDay/toJSON", "Temporal.PlainMonthDay.prototype.toJSON()")}}
+- {{jsxref("Temporal/PlainMonthDay/toLocaleString", "Temporal.PlainMonthDay.prototype.toLocaleString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plainmonthday/with/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plainmonthday/with/index.md
new file mode 100644
index 000000000000000..614716915d85f7e
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plainmonthday/with/index.md
@@ -0,0 +1,75 @@
+---
+title: Temporal.PlainMonthDay.prototype.with()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainMonthDay/with
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainMonthDay.with
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`with()`** method of {{jsxref("Temporal.PlainMonthDay")}} instances returns a new `Temporal.PlainMonthDay` object representing this month-day with some fields replaced by new values. Because all `Temporal` objects are designed to be immutable, this method essentially functions as the setter for the month-day's fields.
+
+There's no obvious way to create a new `Temporal.PlainMonthDay` object that represents the same month-day in a different calendar, so to replace its `calendarId` property, you need to convert it to a {{jsxref("Temporal.PlainDate")}} object using {{jsxref("Temporal/PlainMonthDay/toPlainDate", "toPlainDate()")}}, change the calendar, and then convert it back.
+
+## Syntax
+
+```js-nolint
+with(info)
+with(info, options)
+```
+
+### Parameters
+
+- `info`
+  - : An object containing at least one of the properties recognized by {{jsxref("Temporal/PlainMonthDay/from", "Temporal.PlainMonthDay.from()")}} (except `calendar`): `day`, `era` and `eraYear`, `month`, `monthCode`, `year`. Unspecified properties use the values from the original month-day. You need to provide the year if and only if you provide `month` and the calendar is not `iso8601`. You only need to provide one of `month` or `monthCode`, and one of `era` and `eraYear` or `year`, and the other will be updated accordingly.
+- `options` {{optional_inline}}
+  - : An object containing the following property:
+    - `overflow` {{optional_inline}}
+      - : A string specifying the behavior when a date component is out of range. Possible values are:
+        - `"constrain"` (default)
+          - : The date component is [clamped](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate#invalid_date_clamping) to the valid range.
+        - `"reject"`
+          - : A {{jsxref("RangeError")}} is thrown if the date component is out of range.
+
+### Return value
+
+A new `Temporal.PlainMonthDay` object, where the fields specified in `info` that are not `undefined` are replaced by the corresponding values, and the rest of the fields are copied from the original date.
+
+### Exceptions
+
+- {{jsxref("TypeError")}}
+  - : Thrown in one of the following cases:
+    - `info` is not an object.
+    - `options` is not an object or `undefined`.
+- {{jsxref("RangeError")}}
+  - : Thrown in one of the following cases:
+    - The provided properties that specify the same component are inconsistent.
+    - The provided non-numerical properties are not valid; for example, if `monthCode` is never a valid month code in this calendar.
+    - The provided numerical properties are out of range, and `options.overflow` is set to `"reject"`.
+
+## Examples
+
+### Using with()
+
+```js
+const md = Temporal.PlainMonthDay.from("07-01");
+const newMd = md.with({ day: 2 });
+console.log(newMd.toString()); // "07-02"
+```
+
+For more examples, see the documentation for the individual properties that can be set using `with()`.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainMonthDay")}}
+- {{jsxref("Temporal/PlainMonthDay/from", "Temporal.PlainMonthDay.from()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/add/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/add/index.md
new file mode 100644
index 000000000000000..56fe582acf53e24
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/add/index.md
@@ -0,0 +1,70 @@
+---
+title: Temporal.PlainTime.prototype.add()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainTime/add
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainTime.add
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`add()`** method of {{jsxref("Temporal.PlainTime")}} instances returns a new `Temporal.PlainTime` object representing this time moved forward by a given duration (in a form convertible by {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}), wrapping around the clock if necessary.
+
+## Syntax
+
+```js-nolint
+add(duration)
+```
+
+### Parameters
+
+- `duration`
+  - : A string, an object, or a {{jsxref("Temporal.Duration")}} instance representing a duration to add to this time. It is converted to a `Temporal.Duration` object using the same algorithm as {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}.
+
+### Return value
+
+A new `Temporal.PlainTime` object representing the time specified by the original `PlainTime`, plus the duration. Any units above `hours` are ignored, and if the time goes past midnight, it wraps around to the next day.
+
+Adding a duration is equivalent to [subtracting](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainTime/subtract) its [negation](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration/negated).
+
+## Examples
+
+### Adding a duration
+
+```js
+const start = Temporal.PlainTime.from("12:34:56");
+const end = start.add({ hours: 1, minutes: 30 });
+console.log(end.toString()); // 14:04:56
+
+const end2 = start.add({ hours: -1, minutes: -30 });
+console.log(end2.toString()); // 11:04:56
+
+const distance = Temporal.PlainTime.from("00:00:00").until("01:23:45"); // 1h 23m 45s
+const end3 = start.add(distance);
+console.log(end3.toString()); // 13:58:41
+```
+
+### Time wrapping
+
+If the time goes past midnight, it wraps around to the next day:
+
+```js
+const start = Temporal.PlainTime.from("12:34:56");
+const end = start.add({ hours: 12 });
+console.log(end.toString()); // 00:34:56
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainTime")}}
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/PlainTime/subtract", "Temporal.PlainTime.prototype.subtract()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/compare/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/compare/index.md
new file mode 100644
index 000000000000000..3fd062e8731c293
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/compare/index.md
@@ -0,0 +1,67 @@
+---
+title: Temporal.PlainTime.compare()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainTime/compare
+page-type: javascript-static-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainTime.compare
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.PlainTime.compare()`** static method returns a number (-1, 0, or 1) indicating whether the first time comes before, is the same as, or comes after the second time. It is equivalent to comparing the hour, minute, second, millisecond, microsecond, and nanosecond fields one by one.
+
+## Syntax
+
+```js-nolint
+Temporal.PlainTime.compare(time1, time2)
+```
+
+### Parameters
+
+- `time1`
+  - : A string, an object, or a {{jsxref("Temporal.PlainTime")}} instance representing the first time to compare. It is converted to a `Temporal.PlainTime` object using the same algorithm as {{jsxref("Temporal/PlainTime/from", "Temporal.PlainTime.from()")}}.
+- `time2`
+  - : The second time to compare, converted to a `Temporal.PlainTime` object using the same algorithm as `time1`.
+
+### Return value
+
+Returns `-1` if `time1` comes before `time2`, `0` if they are the same, and `1` if `time2` comes after.
+
+## Examples
+
+### Using Temporal.PlainTime.compare()
+
+```js
+const time1 = Temporal.PlainTime.from("12:34:56");
+const time2 = Temporal.PlainTime.from("12:34:57");
+console.log(Temporal.PlainTime.compare(time1, time2)); // -1
+
+const time3 = Temporal.PlainTime.from("11:34:56");
+console.log(Temporal.PlainTime.compare(time1, time3)); // 1
+```
+
+### Sorting an array of times
+
+The purpose of this `compare()` function is to act as a comparator to be passed to {{jsxref("Array.prototype.sort()")}} and related functions.
+
+```js
+const times = ["12:34:56", "11:34:56", "12:34:57"];
+
+times.sort(Temporal.PlainTime.compare);
+console.log(times);
+// [ "11:34:56", "12:34:56", "12:34:57" ]
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainTime")}}
+- {{jsxref("Temporal/PlainTime/equals", "Temporal.PlainTime.prototype.equals()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/equals/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/equals/index.md
new file mode 100644
index 000000000000000..8d117685d414f2d
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/equals/index.md
@@ -0,0 +1,53 @@
+---
+title: Temporal.PlainTime.prototype.equals()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainTime/equals
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainTime.equals
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`equals()`** method of {{jsxref("Temporal.PlainTime")}} instances returns `true` if this time is equivalent in value to another time (in a form convertible by {{jsxref("Temporal/PlainTime/from", "Temporal.PlainTime.from()")}}), and `false` otherwise. They are compared by their time values. It is equivalent to `Temporal.PlainTime.compare(this, other) === 0`.
+
+## Syntax
+
+```js-nolint
+equals(other)
+```
+
+### Parameters
+
+- `other`
+  - : A string, an object, or a {{jsxref("Temporal.PlainTime")}} instance representing the other time to compare. It is converted to a `Temporal.PlainTime` object using the same algorithm as {{jsxref("Temporal/PlainTime/from", "Temporal.PlainTime.from()")}}.
+
+### Return value
+
+`true` if this time is equal to `other` both in their time value and their calendar, `false` otherwise.
+
+## Examples
+
+### Using equals()
+
+```js
+const time1 = Temporal.PlainTime.from("12:34:56");
+const time2 = Temporal.PlainTime.from({ hour: 12, minute: 34, second: 56 });
+console.log(time1.equals(time2)); // true
+
+const time3 = Temporal.PlainTime.from("00:34:56");
+console.log(time1.equals(time3)); // false
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainTime")}}
+- {{jsxref("Temporal/PlainTime/compare", "Temporal.PlainTime.compare()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/from/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/from/index.md
new file mode 100644
index 000000000000000..0e47bb2218a00f5
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/from/index.md
@@ -0,0 +1,142 @@
+---
+title: Temporal.PlainTime.from()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainTime/from
+page-type: javascript-static-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainTime.from
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.PlainTime.from()`** static method creates a new `Temporal.PlainTime` object from another `Temporal.PlainTime` object, an object with time properties, or an [RFC 9557](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainTime#rfc_9557_format) string.
+
+## Syntax
+
+```js-nolint
+Temporal.PlainTime.from(info)
+Temporal.PlainTime.from(info, options)
+```
+
+### Parameters
+
+- `info`
+
+  - : One of the following:
+
+    - A {{jsxref("Temporal.PlainTime")}} instance, which creates a copy of the instance.
+    - A {{jsxref("Temporal.PlainDateTime")}} instance, which provides the time in the same fashion as {{jsxref("Temporal/PlainDateTime/toPlainDate", "Temporal.PlainDateTime.prototype.toPlainTime()")}}.
+    - A {{jsxref("Temporal.ZonedDateTime")}} instance, which provides the time in the same fashion as {{jsxref("Temporal/ZonedDateTime/toPlainDate", "Temporal.ZonedDateTime.prototype.toPlainTime()")}}.
+    - An [RFC 9557](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainTime#rfc_9557_format) string containing a time.
+    - An object containing at least one of the following properties (in the order they are retrieved and validated):
+
+      - {{jsxref("Temporal/PlainTime/hour", "hour")}}
+      - {{jsxref("Temporal/PlainTime/microsecond", "microsecond")}}
+      - {{jsxref("Temporal/PlainTime/millisecond", "millisecond")}}
+      - {{jsxref("Temporal/PlainTime/minute", "minute")}}
+      - {{jsxref("Temporal/PlainTime/nanosecond", "nanosecond")}}
+      - {{jsxref("Temporal/PlainTime/second", "second")}}
+
+      They are truncated to be integers. Out-of-range values are handled by the `overflow` option.
+
+- `options` {{optional_inline}}
+  - : An object containing the following property:
+    - `overflow` {{optional_inline}}
+      - : A string specifying the behavior when a time component is out of range (when using the object `info`). Possible values are:
+        - `"constrain"` (default)
+          - : The time component is clamped to the valid range.
+        - `"reject"`
+          - : A {{jsxref("RangeError")}} is thrown if the time component is out of range.
+
+### Return value
+
+A new `Temporal.PlainTime` object, representing the time specified by `info`.
+
+### Exceptions
+
+- {{jsxref("TypeError")}}
+  - : Thrown in one of the following cases:
+    - `info` is not an object with at least one recognized property or a string.
+    - `options` is not an object or `undefined`.
+- {{jsxref("RangeError")}}
+  - : Thrown if the provided numerical properties are out of range, and `options.overflow` is set to `"reject"`.
+
+## Examples
+
+### Creating a PlainTime from an object
+
+```js
+const t1 = Temporal.PlainTime.from({ hour: 0 });
+console.log(t1.toString()); // "00:00:00"
+
+const t2 = Temporal.PlainTime.from({ hour: 12, minute: 34, second: 56 });
+console.log(t2.toString()); // "12:34:56"
+
+const t3 = Temporal.PlainTime.from({
+  hour: 12,
+  minute: 34,
+  second: 56,
+  millisecond: 123,
+  microsecond: 456,
+  nanosecond: 789,
+});
+console.log(t3.toString()); // "12:34:56.123456789"
+```
+
+### Controlling overflow behavior
+
+By default, out-of-range values are clamped to the valid range:
+
+```js
+const t1 = Temporal.PlainTime.from({ hour: 25 });
+console.log(t1.toString()); // "23:00:00"
+
+const t2 = Temporal.PlainTime.from({ hour: 25, minute: 60 });
+console.log(t2.toString()); // "23:59:00"
+```
+
+You can change this behavior to throw an error instead:
+
+```js
+Temporal.PlainTime.from({ hour: 25 }, { overflow: "reject" });
+// RangeError: time value "hour" not in 0..23: 25
+```
+
+### Creating a PlainTime from a string
+
+```js
+const t1 = Temporal.PlainTime.from("12:34:56.123456789");
+console.log(t1.toLocaleString("en-US", { timeStyle: "full" }));
+// 12:34:56 PM
+```
+
+### Creating a PlainTime from another Temporal instance
+
+```js
+const dt = Temporal.PlainDateTime.from("2021-07-01T12:00");
+const t = Temporal.PlainTime.from(dt);
+console.log(t.toString()); // "12:00:00"
+
+const zdt = Temporal.ZonedDateTime.from(
+  "2021-07-01T00:00+08:00[Asia/Shanghai]",
+);
+const t2 = Temporal.PlainTime.from(zdt);
+console.log(t2.toString()); // "00:00:00"
+
+const t3 = Temporal.PlainTime.from(t);
+console.log(t3.toString()); // "12:00:00"
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainTime")}}
+- {{jsxref("Temporal/PlainTime/PlainTime", "Temporal.PlainTime()")}}
+- {{jsxref("Temporal/PlainTime/with", "Temporal.PlainTime.prototype.with()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/hour/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/hour/index.md
new file mode 100644
index 000000000000000..5ff65352e6315a1
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/hour/index.md
@@ -0,0 +1,54 @@
+---
+title: Temporal.PlainTime.prototype.hour
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainTime/hour
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainTime.hour
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`hour`** accessor property of {{jsxref("Temporal.PlainTime")}} instances returns a integer from 0 to 23 representing the hour component of this time.
+
+The set accessor of `hour` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/PlainTime/with", "with()")}} method to create a new `Temporal.PlainTime` object with the desired new value.
+
+## Examples
+
+### Using hour
+
+```js
+const time = Temporal.PlainTime.from("12:34:56");
+console.log(time.hour); // 12
+```
+
+### Changing hour
+
+```js
+const time = Temporal.PlainTime.from("12:34:56");
+const newTime = time.with({ hour: 15 });
+console.log(newTime.toString()); // 15:34:56
+```
+
+You can also use {{jsxref("Temporal/PlainTime/add", "add()")}} or {{jsxref("Temporal/PlainTime/subtract", "subtract()")}} to move a certain number of hours from the current time.
+
+```js
+const time = Temporal.PlainTime.from("12:34:56");
+const newTime = time.add({ hours: 3 });
+console.log(newTime.toString()); // 15:34:56
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainTime")}}
+- {{jsxref("Temporal/PlainTime/with", "Temporal.PlainTime.prototype.with()")}}
+- {{jsxref("Temporal/PlainTime/add", "Temporal.PlainTime.prototype.add()")}}
+- {{jsxref("Temporal/PlainTime/subtract", "Temporal.PlainTime.prototype.subtract()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/index.md
new file mode 100644
index 000000000000000..2940c47296d8e6d
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/index.md
@@ -0,0 +1,107 @@
+---
+title: Temporal.PlainTime
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainTime
+page-type: javascript-class
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainTime
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.PlainTime`** object represents a time without a date or time zone; for example, a recurring event that happens at the same time every day. It is fundamentally represented as a combination of hour, minute, second, millisecond, microsecond, and nanosecond values.
+
+## Description
+
+A `PlainTime` is essentially the time part of a {{jsxref("Temporal.PlainDateTime")}} object, with the date information removed. Because the date and time information don't have much interaction, all general information about time properties is documented here.
+
+### RFC 9557 format
+
+`PlainTime` objects can be serialized and parsed using the [RFC 9557](https://datatracker.ietf.org/doc/html/rfc9557) format, an extension to the [ISO 8601 / RFC 3339](https://datatracker.ietf.org/doc/html/rfc3339) format. The string has the following form:
+
+```plain
+HH:mm:ss.sssssssss
+```
+
+- `HH`
+  - : A two-digit number from `00` to `23`. It may be prefixed by the time designator `T` or `t`.
+- `mm` {{optional_inline}}
+  - : A two-digit number from `00` to `59`. Defaults to `00`.
+- `ss.sssssssss` {{optional_inline}}
+  - : A two-digit number from `00` to `59`. May optionally be followed by a `.` or `,` and one to nine digits. Defaults to `00`. The `HH`, `mm`, and `ss` components can be separated by `:` or nothing. You can omit either just `ss` or both `ss` and `mm`, so the time can be one of three forms: `HH`, `HH:mm`, or `HH:mm:ss.sssssssss`.
+
+As an input, you may optionally include the date, offset, time zone identifier, and calendar, in the same format as [`PlainDateTime`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime#rfc_9557_format), but they will be ignored. A date-only string will be rejected. Other annotations in the `[key=value]` format are also ignored, and they must not have the critical flag.
+
+When serializing, you can configure the fractional second digits.
+
+## Constructor
+
+- {{jsxref("Temporal/PlainTime/PlainTime", "Temporal.PlainTime()")}} {{experimental_inline}}
+  - : Creates a new `Temporal.PlainTime` object by directly supplying the underlying data.
+
+## Static methods
+
+- {{jsxref("Temporal/PlainTime/compare", "Temporal.PlainTime.compare()")}} {{experimental_inline}}
+  - : Returns a number (-1, 0, or 1) indicating whether the first time comes before, is the same as, or comes after the second time. Equivalent to comparing the hour, minute, second, millisecond, microsecond, and nanosecond fields one by one.
+- {{jsxref("Temporal/PlainTime/from", "Temporal.PlainTime.from()")}} {{experimental_inline}}
+  - : Creates a new `Temporal.PlainTime` object from another `Temporal.PlainTime` object, an object with time properties, or an [RFC 9557](#rfc_9557_format) string.
+
+## Instance properties
+
+These properties are defined on `Temporal.PlainTime.prototype` and shared by all `Temporal.PlainTime` instances.
+
+- {{jsxref("Object/constructor", "Temporal.PlainTime.prototype.constructor")}}
+  - : The constructor function that created the instance object. For `Temporal.PlainTime` instances, the initial value is the {{jsxref("Temporal/PlainTime/PlainTime", "Temporal.PlainTime()")}} constructor.
+- {{jsxref("Temporal/PlainTime/hour", "Temporal.PlainTime.prototype.hour")}} {{experimental_inline}}
+  - : Returns a integer from 0 to 23 representing the hour component of this time.
+- {{jsxref("Temporal/PlainTime/microsecond", "Temporal.PlainTime.prototype.microsecond")}} {{experimental_inline}}
+  - : Returns a integer from 0 to 999 representing the microsecond (10<sup>-6</sup> second) component of this time.
+- {{jsxref("Temporal/PlainTime/millisecond", "Temporal.PlainTime.prototype.millisecond")}} {{experimental_inline}}
+  - : Returns a integer from 0 to 999 representing the millisecond (10<sup>-3</sup> second) component of this time.
+- {{jsxref("Temporal/PlainTime/minute", "Temporal.PlainTime.prototype.minute")}} {{experimental_inline}}
+  - : Returns a integer from 0 to 59 representing the minute component of this time.
+- {{jsxref("Temporal/PlainTime/nanosecond", "Temporal.PlainTime.prototype.nanosecond")}} {{experimental_inline}}
+  - : Returns a integer from 0 to 999 representing the nanosecond (10<sup>-9</sup> second) component of this time.
+- {{jsxref("Temporal/PlainTime/second", "Temporal.PlainTime.prototype.second")}} {{experimental_inline}}
+  - : Returns a integer from 0 to 59 representing the second component of this time.
+- `Temporal.PlainTime.prototype[Symbol.toStringTag]`
+  - : The initial value of the [`[Symbol.toStringTag]`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol/toStringTag) property is the string `"Temporal.PlainTime"`. This property is used in {{jsxref("Object.prototype.toString()")}}.
+
+## Instance methods
+
+- {{jsxref("Temporal/PlainTime/add", "Temporal.PlainTime.prototype.add()")}} {{experimental_inline}}
+  - : Returns a new `Temporal.PlainTime` object representing this time moved forward by a given duration (in a form convertible by {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}), wrapping around the clock if necessary.
+- {{jsxref("Temporal/PlainTime/equals", "Temporal.PlainTime.prototype.equals()")}} {{experimental_inline}}
+  - : Returns `true` if this time is equivalent in value to another time (in a form convertible by {{jsxref("Temporal/PlainTime/from", "Temporal.PlainTime.from()")}}), and `false` otherwise. They are compared by their time values. Equivalent to `Temporal.PlainTime.compare(this, other) === 0`.
+- {{jsxref("Temporal/PlainTime/round", "Temporal.PlainTime.prototype.round()")}} {{experimental_inline}}
+  - : Returns a new `Temporal.PlainTime` object representing this time rounded to the given unit.
+- {{jsxref("Temporal/PlainTime/since", "Temporal.PlainTime.prototype.since()")}} {{experimental_inline}}
+  - : Returns a new {{jsxref("Temporal.Duration")}} object representing the duration from another time (in a form convertible by {{jsxref("Temporal/PlainTime/from", "Temporal.PlainTime.from()")}}) to this time. The duration is positive if the other time is before this time, and negative if after.
+- {{jsxref("Temporal/PlainTime/subtract", "Temporal.PlainTime.prototype.subtract()")}} {{experimental_inline}}
+  - : Returns a new `Temporal.PlainTime` object representing this time moved backward by a given duration (in a form convertible by {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}), wrapping around the clock if necessary.
+- {{jsxref("Temporal/PlainTime/toJSON", "Temporal.PlainTime.prototype.toJSON()")}} {{experimental_inline}}
+  - : Returns a string representing this time in the same [RFC 9557 format](#rfc_9557_format) as calling {{jsxref("Temporal/PlainTime/toString", "toString()")}}. Intended to be implicitly called by {{jsxref("JSON.stringify()")}}.
+- {{jsxref("Temporal/PlainTime/toLocaleString", "Temporal.PlainTime.prototype.toLocaleString()")}} {{experimental_inline}}
+  - : Returns a string with a language-sensitive representation of this time.
+- {{jsxref("Temporal/PlainTime/toString", "Temporal.PlainTime.prototype.toString()")}} {{experimental_inline}}
+  - : Returns a string representing this time in the [RFC 9557 format](#rfc_9557_format).
+- {{jsxref("Temporal/PlainTime/until", "Temporal.PlainTime.prototype.until()")}} {{experimental_inline}}
+  - : Returns a new {{jsxref("Temporal.Duration")}} object representing the duration from this time to another time (in a form convertible by {{jsxref("Temporal/PlainTime/from", "Temporal.PlainTime.from()")}}). The duration is positive if the other time is after this time, and negative if before.
+- {{jsxref("Temporal/PlainTime/valueOf", "Temporal.PlainTime.prototype.valueOf()")}} {{experimental_inline}}
+  - : Throws a {{jsxref("TypeError")}}, which prevents `Temporal.PlainTime` instances from being [implicitly converted to primitives](/en-US/docs/Web/JavaScript/Data_structures#primitive_coercion) when used in arithmetic or comparison operations.
+- {{jsxref("Temporal/PlainTime/with", "Temporal.PlainTime.prototype.with()")}} {{experimental_inline}}
+  - : Returns a new `Temporal.PlainTime` object representing this time with some fields replaced by new values.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal")}}
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal.PlainDateTime")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/microsecond/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/microsecond/index.md
new file mode 100644
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--- /dev/null
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@@ -0,0 +1,60 @@
+---
+title: Temporal.PlainTime.prototype.microsecond
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainTime/microsecond
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainTime.microsecond
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`microsecond`** accessor property of {{jsxref("Temporal.PlainTime")}} instances returns a integer from 0 to 999 representing the microsecond (10<sup>-6</sup> second) component of this time.
+
+The set accessor of `microsecond` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/PlainTime/with", "with()")}} method to create a new `Temporal.PlainTime` object with the desired new value.
+
+## Examples
+
+### Using microsecond
+
+```js
+const time = Temporal.PlainTime.from("12:34:56");
+console.log(time.microsecond); // 0
+
+const time2 = Temporal.PlainTime.from("12:34:56.123456789");
+console.log(time2.microsecond); // 456
+```
+
+### Changing microsecond
+
+```js
+const time = Temporal.PlainTime.from("12:34:56");
+const newTime = time.with({ microsecond: 100 });
+console.log(newTime.toString()); // 12:34:56.0001
+```
+
+You can also use {{jsxref("Temporal/PlainTime/add", "add()")}} or {{jsxref("Temporal/PlainTime/subtract", "subtract()")}} to move a certain number of microseconds from the current time.
+
+```js
+const time = Temporal.PlainTime.from("12:34:56");
+const newTime = time.add({ microseconds: 100 });
+console.log(newTime.toString()); // 12:34:56.0001
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainTime")}}
+- {{jsxref("Temporal/PlainTime/with", "Temporal.PlainTime.prototype.with()")}}
+- {{jsxref("Temporal/PlainTime/add", "Temporal.PlainTime.prototype.add()")}}
+- {{jsxref("Temporal/PlainTime/subtract", "Temporal.PlainTime.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainTime/second", "Temporal.PlainTime.prototype.second")}}
+- {{jsxref("Temporal/PlainTime/millisecond", "Temporal.PlainTime.prototype.millisecond")}}
+- {{jsxref("Temporal/PlainTime/nanosecond", "Temporal.PlainTime.prototype.nanosecond")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/millisecond/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/millisecond/index.md
new file mode 100644
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--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/millisecond/index.md
@@ -0,0 +1,60 @@
+---
+title: Temporal.PlainTime.prototype.millisecond
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainTime/millisecond
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainTime.millisecond
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`millisecond`** accessor property of {{jsxref("Temporal.PlainTime")}} instances returns a integer from 0 to 999 representing the millisecond (10<sup>-3</sup> second) component of this time.
+
+The set accessor of `millisecond` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/PlainTime/with", "with()")}} method to create a new `Temporal.PlainTime` object with the desired new value.
+
+## Examples
+
+### Using millisecond
+
+```js
+const time = Temporal.PlainTime.from("12:34:56");
+console.log(time.millisecond); // 0
+
+const time2 = Temporal.PlainTime.from("12:34:56.123456789");
+console.log(time2.millisecond); // 123
+```
+
+### Changing millisecond
+
+```js
+const time = Temporal.PlainTime.from("12:34:56");
+const newTime = time.with({ millisecond: 100 });
+console.log(newTime.toString()); // 12:34:56.1
+```
+
+You can also use {{jsxref("Temporal/PlainTime/add", "add()")}} or {{jsxref("Temporal/PlainTime/subtract", "subtract()")}} to move a certain number of milliseconds from the current time.
+
+```js
+const time = Temporal.PlainTime.from("12:34:56");
+const newTime = time.add({ milliseconds: 100 });
+console.log(newTime.toString()); // 12:34:56.1
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainTime")}}
+- {{jsxref("Temporal/PlainTime/with", "Temporal.PlainTime.prototype.with()")}}
+- {{jsxref("Temporal/PlainTime/add", "Temporal.PlainTime.prototype.add()")}}
+- {{jsxref("Temporal/PlainTime/subtract", "Temporal.PlainTime.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainTime/second", "Temporal.PlainTime.prototype.second")}}
+- {{jsxref("Temporal/PlainTime/microsecond", "Temporal.PlainTime.prototype.microsecond")}}
+- {{jsxref("Temporal/PlainTime/nanosecond", "Temporal.PlainTime.prototype.nanosecond")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/minute/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/minute/index.md
new file mode 100644
index 000000000000000..dce393d249dd529
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/minute/index.md
@@ -0,0 +1,54 @@
+---
+title: Temporal.PlainTime.prototype.minute
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainTime/minute
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainTime.minute
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`minute`** accessor property of {{jsxref("Temporal.PlainTime")}} instances returns a integer from 0 to 59 representing the minute component of this time.
+
+The set accessor of `minute` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/PlainTime/with", "with()")}} method to create a new `Temporal.PlainTime` object with the desired new value.
+
+## Examples
+
+### Using minute
+
+```js
+const time = Temporal.PlainTime.from("12:34:56");
+console.log(time.minute); // 34
+```
+
+### Changing minute
+
+```js
+const time = Temporal.PlainTime.from("12:34:56");
+const newTime = time.with({ minute: 58 });
+console.log(newTime.toString()); // 12:58:56
+```
+
+You can also use {{jsxref("Temporal/PlainTime/add", "add()")}} or {{jsxref("Temporal/PlainTime/subtract", "subtract()")}} to move a certain number of minutes from the current time.
+
+```js
+const time = Temporal.PlainTime.from("12:34:56");
+const newTime = time.add({ minutes: 24 });
+console.log(newTime.toString()); // 12:58:56
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainTime")}}
+- {{jsxref("Temporal/PlainTime/with", "Temporal.PlainTime.prototype.with()")}}
+- {{jsxref("Temporal/PlainTime/add", "Temporal.PlainTime.prototype.add()")}}
+- {{jsxref("Temporal/PlainTime/subtract", "Temporal.PlainTime.prototype.subtract()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/nanosecond/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/nanosecond/index.md
new file mode 100644
index 000000000000000..2588eb88a238731
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/nanosecond/index.md
@@ -0,0 +1,60 @@
+---
+title: Temporal.PlainTime.prototype.nanosecond
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainTime/nanosecond
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainTime.nanosecond
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`nanosecond`** accessor property of {{jsxref("Temporal.PlainTime")}} instances returns a integer from 0 to 999 representing the nanosecond (10<sup>-9</sup> second) component of this time.
+
+The set accessor of `nanosecond` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/PlainTime/with", "with()")}} method to create a new `Temporal.PlainTime` object with the desired new value.
+
+## Examples
+
+### Using nanosecond
+
+```js
+const time = Temporal.PlainTime.from("12:34:56");
+console.log(time.nanosecond); // 0
+
+const time2 = Temporal.PlainTime.from("12:34:56.123456789");
+console.log(time2.nanosecond); // 789
+```
+
+### Changing nanosecond
+
+```js
+const time = Temporal.PlainTime.from("12:34:56");
+const newTime = time.with({ nanosecond: 100 });
+console.log(newTime.toString()); // 12:34:56.0000001
+```
+
+You can also use {{jsxref("Temporal/PlainTime/add", "add()")}} or {{jsxref("Temporal/PlainTime/subtract", "subtract()")}} to move a certain number of nanoseconds from the current time.
+
+```js
+const time = Temporal.PlainTime.from("12:34:56");
+const newTime = time.add({ nanoseconds: 100 });
+console.log(newTime.toString()); // 12:34:56.0000001
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainTime")}}
+- {{jsxref("Temporal/PlainTime/with", "Temporal.PlainTime.prototype.with()")}}
+- {{jsxref("Temporal/PlainTime/add", "Temporal.PlainTime.prototype.add()")}}
+- {{jsxref("Temporal/PlainTime/subtract", "Temporal.PlainTime.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainTime/second", "Temporal.PlainTime.prototype.second")}}
+- {{jsxref("Temporal/PlainTime/millisecond", "Temporal.PlainTime.prototype.millisecond")}}
+- {{jsxref("Temporal/PlainTime/microsecond", "Temporal.PlainTime.prototype.microsecond")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/plaintime/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/plaintime/index.md
new file mode 100644
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--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/plaintime/index.md
@@ -0,0 +1,74 @@
+---
+title: Temporal.PlainTime()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainTime/PlainTime
+page-type: javascript-constructor
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainTime.PlainTime
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.PlainTime()`** constructor creates {{jsxref("Temporal.PlainTime")}} objects.
+
+This constructor allows you to create instances by directly supplying the underlying data. Like all other `Temporal` classes, you should usually construct `Temporal.PlainTime` objects using the {{jsxref("Temporal/PlainTime/from", "Temporal.PlainTime.from()")}} static method, which can handle a variety of input types.
+
+## Syntax
+
+```js-nolint
+new Temporal.PlainTime()
+new Temporal.PlainTime(hour)
+new Temporal.PlainTime(hour, minute)
+new Temporal.PlainTime(hour, minute, second)
+new Temporal.PlainTime(hour, minute, second, millisecond)
+new Temporal.PlainTime(hour, minute, second, millisecond, microsecond)
+new Temporal.PlainTime(hour, minute, second, millisecond, microsecond, nanosecond)
+```
+
+> **Note:** `Temporal.PlainTime()` can only be constructed with [`new`](/en-US/docs/Web/JavaScript/Reference/Operators/new). Attempting to call it without `new` throws a {{jsxref("TypeError")}}.
+
+### Parameters
+
+- `hour` {{optional_inline}}
+  - : A number, truncated to an integer, representing the hour component.
+- `minute` {{optional_inline}}
+  - : A number, truncated to an integer, representing the minute component.
+- `second` {{optional_inline}}
+  - : A number, truncated to an integer, representing the second component.
+- `millisecond` {{optional_inline}}
+  - : A number, truncated to an integer, representing the millisecond component.
+- `microsecond` {{optional_inline}}
+  - : A number, truncated to an integer, representing the microsecond component.
+- `nanosecond` {{optional_inline}}
+  - : A number, truncated to an integer, representing the nanosecond component.
+
+### Return value
+
+A new `Temporal.PlainTime` object, representing the time specified by the parameters.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown if any of the components is not a finite number, or they don't represent a valid time.
+
+## Examples
+
+### Using Temporal.PlainTime()
+
+```js
+const time = new Temporal.PlainTime(12, 34, 56, 123, 456, 789);
+console.log(time.toString()); // 12:34:56.123456789
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainTime")}}
+- {{jsxref("Temporal/PlainTime/from", "Temporal.PlainTime.from()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/round/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/round/index.md
new file mode 100644
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--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/round/index.md
@@ -0,0 +1,72 @@
+---
+title: Temporal.PlainTime.prototype.round()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainTime/round
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainTime.round
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`round()`** method of {{jsxref("Temporal.PlainTime")}} instances returns a new `Temporal.PlainTime` object representing this time rounded to the given unit.
+
+## Syntax
+
+```js-nolint
+round(smallestUnit)
+round(options)
+```
+
+### Parameters
+
+- `smallestUnit`
+  - : A string representing the [`smallestUnit`](#smallestunit_2) option. This is a convenience overload, so `round(smallestUnit)` is equivalent to `round({ smallestUnit })`, where `smallestUnit` is a string.
+- `options`
+  - : An object containing some or all of the following properties (in the order they are retrieved and validated):
+    - `roundingIncrement` {{optional_inline}}
+      - : A number (truncated to an integer) representing the rounding increment in the given `smallestUnit`. Defaults to `1`. The increment must be a divisor of the maximum value of `smallestUnit`; for example, if the unit is hours, the increment must be a divisor of 24 and must not be 24 itself, which means it can be 1, 2, 3, 4, 6, 8, or 12.
+    - `roundingMode` {{optional_inline}}
+      - : A string specifying how to round off the fractional part of `smallestUnit`. See [`Intl.NumberFormat()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/NumberFormat/NumberFormat#roundingmode). Defaults to `"halfExpand"`.
+    - `smallestUnit`
+      - : A string representing the smallest unit to include in the output. The value must be one of the following: `"hour"`, `"minute"`, `"second"`, `"millisecond"`, `"microsecond"`, `"nanosecond"`, or their plural forms. For units larger than `"nanosecond"`, fractional parts of the `smallestUnit` will be rounded according to the `roundingIncrement` and `roundingMode` settings.
+
+### Return value
+
+A new {{jsxref("Temporal.PlainTime")}} object representing this time rounded to the given unit, where all units smaller than `smallestUnit` are zeroed out.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown if any of the options is invalid.
+
+## Examples
+
+### Rounding off small units
+
+```js
+const time = Temporal.PlainTime.from("12:34:56.123456789");
+const nearestMillisecond = time.round("millisecond");
+console.log(nearestMillisecond.toString()); // 12:34:56.123
+
+const nearestHalfHour = time.round({
+  smallestUnit: "minute",
+  roundingIncrement: 30,
+});
+console.log(nearestHalfHour.toString()); // 12:30:00
+
+const nextHour = time.round({ smallestUnit: "hour", roundingMode: "ceil" });
+console.log(nextHour.toString()); // 13:00:00
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainTime")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/second/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/second/index.md
new file mode 100644
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--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/second/index.md
@@ -0,0 +1,57 @@
+---
+title: Temporal.PlainTime.prototype.second
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainTime/second
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainTime.second
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`second`** accessor property of {{jsxref("Temporal.PlainTime")}} instances returns a integer from 0 to 59 representing the second component of this time.
+
+The set accessor of `second` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/PlainTime/with", "with()")}} method to create a new `Temporal.PlainTime` object with the desired new value.
+
+## Examples
+
+### Using second
+
+```js
+const time = Temporal.PlainTime.from("12:34:56");
+console.log(time.second); // 56
+```
+
+### Changing second
+
+```js
+const time = Temporal.PlainTime.from("12:34:56");
+const newTime = time.with({ second: 15 });
+console.log(newTime.toString()); // 12:34:15
+```
+
+You can also use {{jsxref("Temporal/PlainTime/add", "add()")}} or {{jsxref("Temporal/PlainTime/subtract", "subtract()")}} to move a certain number of seconds from the current time.
+
+```js
+const time = Temporal.PlainTime.from("12:34:56");
+const newTime = time.subtract({ seconds: 41 });
+console.log(newTime.toString()); // 12:34:15
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainTime")}}
+- {{jsxref("Temporal/PlainTime/with", "Temporal.PlainTime.prototype.with()")}}
+- {{jsxref("Temporal/PlainTime/add", "Temporal.PlainTime.prototype.add()")}}
+- {{jsxref("Temporal/PlainTime/subtract", "Temporal.PlainTime.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainTime/millisecond", "Temporal.PlainTime.prototype.millisecond")}}
+- {{jsxref("Temporal/PlainTime/microsecond", "Temporal.PlainTime.prototype.microsecond")}}
+- {{jsxref("Temporal/PlainTime/nanosecond", "Temporal.PlainTime.prototype.nanosecond")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/since/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/since/index.md
new file mode 100644
index 000000000000000..c67a5fa60c2ac83
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/since/index.md
@@ -0,0 +1,91 @@
+---
+title: Temporal.PlainTime.prototype.since()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainTime/since
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainTime.since
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`since()`** method of {{jsxref("Temporal.PlainTime")}} instances returns a new {{jsxref("Temporal.Duration")}} object representing the duration from another time (in a form convertible by {{jsxref("Temporal/PlainTime/from", "Temporal.PlainTime.from()")}}) to this time. The duration is positive if the other time is before this time, and negative if after.
+
+This method does `this - other`. To do `other - this`, use the {{jsxref("Temporal/PlainTime/until", "until()")}} method.
+
+## Syntax
+
+```js-nolint
+since(other)
+since(other, options)
+```
+
+### Parameters
+
+- `other`
+  - : A string, an object, or a {{jsxref("Temporal.PlainTime")}} instance representing a time to subtract from this time. It is converted to a `Temporal.PlainTime` object using the same algorithm as {{jsxref("Temporal/PlainTime/from", "Temporal.PlainTime.from()")}}.
+- `options` {{optional_inline}}
+  - : An object containing the options for {{jsxref("Temporal/Duration/round", "Temporal.Duration.prototype.round()")}}, which includes `largestUnit`, `roundingIncrement`, `roundingMode`, and `smallestUnit`. `largestUnit` and `smallestUnit` only accept the units: `"hour"`, `"minute"`, `"second"`, `"millisecond"`, `"microsecond"`, `"nanosecond"`, or their plural forms. For `largestUnit`, the default value `"auto"` means `"hour"`. For `smallestUnit`, the default value is `"nanosecond"`.
+
+### Return value
+
+A new {{jsxref("Temporal.Duration")}} object representing the duration _since_ `other` to this time. The duration is positive if `other` is before this time, and negative if after.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown if any of the options is invalid.
+
+## Examples
+
+### Using since()
+
+```js
+const lunchTime = Temporal.PlainTime.from("12:30:00");
+const now = Temporal.Now.plainTimeISO();
+const duration = now.since(lunchTime);
+console.log(`You had lunch ${duration.toLocaleString("en-US")} ago`);
+// Example output: "You had lunch 3 hr, 42 min, 21 sec, 343 ms, 131 μs, 718 ns ago"
+
+const duration2 = now.since(lunchTime, { smallestUnit: "minute" });
+console.log(`You had lunch ${duration2.toLocaleString("en-US")} ago`);
+// Example output: "You had lunch 3 hr, 42 min ago"
+
+const duration3 = now.since(lunchTime, {
+  largestUnit: "minute",
+  smallestUnit: "minute",
+});
+console.log(`You had lunch ${duration3.toLocaleString("en-US")} ago`);
+// Example output: "You had lunch 222 min ago"
+```
+
+### Rounding the result
+
+By default the fractional part of the `smallestUnit` is truncated. You can round it up using the `roundingIncrement` and `roundingMode` options.
+
+```js
+const time1 = Temporal.PlainTime.from("12:30:00");
+const time2 = Temporal.PlainTime.from("12:30:01");
+const duration = time2.since(time1, {
+  smallestUnit: "second",
+  roundingIncrement: 15,
+  roundingMode: "ceil",
+});
+console.log(duration.toString()); // "PT15S"
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainTime")}}
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/PlainTime/add", "Temporal.PlainTime.prototype.add()")}}
+- {{jsxref("Temporal/PlainTime/subtract", "Temporal.PlainTime.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainTime/until", "Temporal.PlainTime.prototype.until()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/subtract/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/subtract/index.md
new file mode 100644
index 000000000000000..14c654ec8835097
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/subtract/index.md
@@ -0,0 +1,59 @@
+---
+title: Temporal.PlainTime.prototype.subtract()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainTime/subtract
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainTime.subtract
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`subtract()`** method of {{jsxref("Temporal.PlainTime")}} instances returns a new `Temporal.PlainTime` object representing this time moved backward by a given duration (in a form convertible by {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}), wrapping around the clock if necessary.
+
+If you want to subtract two times and get a duration, use {{jsxref("Temporal/PlainTime/since", "since()")}} or {{jsxref("Temporal/PlainTime/until", "until()")}} instead.
+
+## Syntax
+
+```js-nolint
+subtract(duration)
+```
+
+### Parameters
+
+- `duration`
+  - : A string, an object, or a {{jsxref("Temporal.Duration")}} instance representing a duration to subtract from this time. It is converted to a `Temporal.Duration` object using the same algorithm as {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}.
+
+### Return value
+
+A new `Temporal.PlainTime` object representing the time specified by the original `PlainTime`, minus the duration.
+
+Subtracting a duration is equivalent to [adding](Web/JavaScript/Reference/Global_Objects/Temporal/PlainTime/add) its [negation](Web/JavaScript/Reference/Global_Objects/Temporal/Duration/negated), so all the same considerations apply.
+
+## Examples
+
+### Subtracting a duration
+
+```js
+const start = Temporal.PlainTime.from("12:34:56");
+const end = start.subtract({ hours: 1, minutes: 30 });
+console.log(end.toString()); // 11:04:56
+```
+
+For more examples, see {{jsxref("Temporal/PlainTime/add", "add()")}}.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainTime")}}
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/PlainTime/add", "Temporal.PlainTime.prototype.add()")}}
+- {{jsxref("Temporal/PlainTime/since", "Temporal.PlainTime.prototype.since()")}}
+- {{jsxref("Temporal/PlainTime/until", "Temporal.PlainTime.prototype.until()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/tojson/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/tojson/index.md
new file mode 100644
index 000000000000000..f1acd71455f2873
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/tojson/index.md
@@ -0,0 +1,70 @@
+---
+title: Temporal.PlainTime.prototype.toJSON()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainTime/toJSON
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainTime.toJSON
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toJSON()`** method of {{jsxref("Temporal.PlainTime")}} instances returns a string representing this time in the same [RFC 9557 format](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainTime#rfc_9557_format) as calling {{jsxref("Temporal/PlainTime/toString", "toString()")}}. It is intended to be implicitly called by {{jsxref("JSON.stringify()")}}.
+
+## Syntax
+
+```js-nolint
+toJSON()
+```
+
+### Parameters
+
+None.
+
+### Return value
+
+A string representing the given time in the [RFC 9557 format](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainTime#rfc_9557_format).
+
+## Description
+
+The `toJSON()` method is automatically called by {{jsxref("JSON.stringify()")}} when a `Temporal.PlainTime` object is stringified. This method is generally intended to, by default, usefully serialize `Temporal.PlainTime` objects during [JSON](/en-US/docs/Glossary/JSON) serialization, which can then be deserialized using the {{jsxref("Temporal/PlainTime/from", "Temporal.PlainTime.from()")}} function as the reviver of {{jsxref("JSON.parse()")}}.
+
+## Examples
+
+### Using toJSON()
+
+```js
+const time = Temporal.PlainTime.from({ hour: 12, minute: 34, second: 56 });
+const timeStr = time.toJSON(); // '12:34:56'
+const t2 = Temporal.PlainTime.from(timeStr);
+```
+
+### JSON serialization and parsing
+
+This example shows how `Temporal.PlainTime` can be serialized as JSON without extra effort, and how to parse it back.
+
+```js
+const time = Temporal.PlainTime.from({ hour: 12, minute: 34, second: 56 });
+const jsonStr = JSON.stringify({ time }); // '{"time":"12:34:56"}'
+const obj = JSON.parse(jsonStr, (key, value) => {
+  if (key === "time") {
+    return Temporal.PlainTime.from(value);
+  }
+  return value;
+});
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainTime")}}
+- {{jsxref("Temporal/PlainTime/from", "Temporal.PlainTime.from()")}}
+- {{jsxref("Temporal/PlainTime/toString", "Temporal.PlainTime.prototype.toString()")}}
+- {{jsxref("Temporal/PlainTime/toLocaleString", "Temporal.PlainTime.prototype.toLocaleString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/tolocalestring/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/tolocalestring/index.md
new file mode 100644
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--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/tolocalestring/index.md
@@ -0,0 +1,93 @@
+---
+title: Temporal.PlainTime.prototype.toLocaleString()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainTime/toLocaleString
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainTime.toLocaleString
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toLocaleString()`** method of {{jsxref("Temporal.PlainTime")}} instances returns a string with a language-sensitive representation of this time. In implementations with [`Intl.DateTimeFormat` API](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat) support, this method delegates to `Intl.DateTimeFormat`.
+
+Every time `toLocaleString` is called, it has to perform a search in a big database of localization strings, which is potentially inefficient. When the method is called many times with the same arguments, it is better to create a {{jsxref("Intl.DateTimeFormat")}} object and use its {{jsxref("Intl/DateTimeFormat/format", "format()")}} method, because a `DateTimeFormat` object remembers the arguments passed to it and may decide to cache a slice of the database, so future `format` calls can search for localization strings within a more constrained context.
+
+## Syntax
+
+```js-nolint
+toLocaleString()
+toLocaleString(locales)
+toLocaleString(locales, options)
+```
+
+### Parameters
+
+The `locales` and `options` parameters customize the behavior of the function and let applications specify the language whose formatting conventions should be used.
+
+In implementations that support the [`Intl.DateTimeFormat` API](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat), these parameters correspond exactly to the [`Intl.DateTimeFormat()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat/DateTimeFormat) constructor's parameters. Implementations without `Intl.DateTimeFormat` support return the exact same string as {{jsxref("Temporal/PlainTime/toString", "toString()")}}, ignoring both parameters.
+
+- `locales` {{optional_inline}}
+  - : A string with a BCP 47 language tag, or an array of such strings. Corresponds to the [`locales`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat/DateTimeFormat#locales) parameter of the `Intl.DateTimeFormat()` constructor.
+- `options` {{optional_inline}}
+
+  - : An object adjusting the output format. Corresponds to the [`options`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat/DateTimeFormat#options) parameter of the `Intl.DateTimeFormat()` constructor. Regarding the [date-time component options](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat/DateTimeFormat#date-time_component_options) and the style shortcuts (`dateStyle` and `timeStyle`), the options should follow one of these forms:
+
+    - Provide none of them: `hour`, `minute`, and `second` will default to `"numeric"`.
+    - Provide `timeStyle` only: it expands to `dayPeriod`, `hour`, `minute`, `second`, and `fractionalSecondDigits` formats.
+    - Provide some date-time component options, where at least one of them is a time option (`dayPeriod`, `hour`, `minute`, `second`, `fractionalSecondDigits`). Only the specified time components will be included in the output.
+
+See the [`Intl.DateTimeFormat()` constructor](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat/DateTimeFormat) for details on these parameters and how to use them.
+
+### Return value
+
+A string representing the given time according to language-specific conventions.
+
+In implementations with `Intl.DateTimeFormat`, this is equivalent to `new Intl.DateTimeFormat(locales, options).format(time)`, where `options` has been normalized as described above.
+
+> [!NOTE]
+> Most of the time, the formatting returned by `toLocaleString()` is consistent. However, the output may vary between implementations, even within the same locale — output variations are by design and allowed by the specification. It may also not be what you expect. For example, the string may use non-breaking spaces or be surrounded by bidirectional control characters. You should not compare the results of `toLocaleString()` to hardcoded constants.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown if any of the options is invalid.
+- {{jsxref("TypeError")}}
+  - : Thrown if any of the options is not of the expected type.
+
+## Examples
+
+### Using toLocaleString()
+
+Basic use of this method without specifying a `locale` returns a formatted string in the default locale and with default options.
+
+```js
+const time = Temporal.PlainTime.from("12:34:56");
+
+console.log(time.toLocaleString()); // 12:34:56 PM (assuming en-US locale)
+```
+
+### Using toLocaleString() with options
+
+You can customize which parts of the time are included in the output by providing the `options` parameter.
+
+```js
+const time = Temporal.PlainTime.from("12:34:56");
+time.toLocaleString("en-US", { timeStyle: "short" }); // 12:34 PM
+time.toLocaleString("en-US", { hour: "2-digit" }); // 12 PM
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainTime")}}
+- {{jsxref("Intl.DateTimeFormat")}}
+- {{jsxref("Temporal/PlainTime/toJSON", "Temporal.PlainTime.prototype.toJSON()")}}
+- {{jsxref("Temporal/PlainTime/toString", "Temporal.PlainTime.prototype.toString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/tostring/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/tostring/index.md
new file mode 100644
index 000000000000000..ea86636ff44d4dc
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/tostring/index.md
@@ -0,0 +1,81 @@
+---
+title: Temporal.PlainTime.prototype.toString()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainTime/toString
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainTime.toString
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toString()`** method of {{jsxref("Temporal.PlainTime")}} instances returns a string representing this time in the [RFC 9557 format](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainTime#rfc_9557_format).
+
+## Syntax
+
+```js-nolint
+toString()
+toString(options)
+```
+
+### Parameters
+
+- `options` {{optional_inline}}
+  - : An object containing some or all of the following properties (in the order they are retrieved and validated):
+    - `fractionalSecondDigits` {{optional_inline}}
+      - : Either an integer from 0 to 9, or the string `"auto"`. The default is `"auto"`. If `"auto"`, then trailing zeros are removed from the fractional seconds. Otherwise, the fractional part of the second component contains this many digits, padded with zeros or rounded as necessary.
+    - `roundingMode` {{optional_inline}}
+      - : A string specifying how to round off fractional second digits beyond `fractionalSecondDigits`. See [`Intl.NumberFormat()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/NumberFormat/NumberFormat#roundingmode). Defaults to `"trunc"`.
+    - `smallestUnit` {{optional_inline}}
+      - : A string specifying the smallest unit to include in the output. Possible values are `"minute"`, `"second"`, `"millisecond"`, `"microsecond"`, and `"nanosecond"`, or their plural forms, which (except `"minute"`) are equivalent to `fractionalSecondDigits` values of `0`, `3`, `6`, `9`, respectively. If specified, then `fractionalSecondDigits` is ignored.
+
+### Return value
+
+A string in the [RFC 9557 format](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainTime#rfc_9557_format) representing this time.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown if any of the options is invalid.
+- {{jsxref("TypeError")}}
+  - : Thrown if `options` is not an object or `undefined`.
+
+## Examples
+
+### Using toString()
+
+```js
+const time = Temporal.PlainTime.from("12:34:56");
+console.log(time.toString()); // '12:34:56'
+```
+
+### Using options
+
+```js
+const time1 = Temporal.PlainTime.from("12:00:00");
+console.log(time1.toString()); // '12:00:00'
+console.log(time1.toString({ fractionalSecondDigits: 1 })); // '12:00:00.0'
+console.log(time1.toString({ smallestUnit: "minute" })); // '12:00'
+console.log(time1.toString({ smallestUnit: "nanosecond" })); // '12:00:00.000000000'
+
+const time2 = Temporal.PlainTime.from("12:34:56.123456789");
+console.log(time2.toString({ fractionalSecondDigits: 4 })); // '12:34:56.1234'
+console.log(
+  time2.toString({ fractionalSecondDigits: 4, roundingMode: "halfExpand" }),
+); // '12:34:56.1235'
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainTime")}}
+- {{jsxref("Temporal/PlainTime/from", "Temporal.PlainTime.from()")}}
+- {{jsxref("Temporal/PlainTime/toJSON", "Temporal.PlainTime.prototype.toJSON()")}}
+- {{jsxref("Temporal/PlainTime/toLocaleString", "Temporal.PlainTime.prototype.toLocaleString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/until/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/until/index.md
new file mode 100644
index 000000000000000..dc7b16e9ba6a48a
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/until/index.md
@@ -0,0 +1,67 @@
+---
+title: Temporal.PlainTime.prototype.until()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainTime/until
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainTime.until
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`until()`** method of {{jsxref("Temporal.PlainTime")}} instances returns a new {{jsxref("Temporal.Duration")}} object representing the duration from this time to another time (in a form convertible by {{jsxref("Temporal/PlainTime/from", "Temporal.PlainTime.from()")}}). The duration is positive if the other time is after this time, and negative if before.
+
+This method does `other - this`. To do `this - other`, use the {{jsxref("Temporal/PlainTime/since", "since()")}} method.
+
+## Syntax
+
+```js-nolint
+until(other)
+until(other, options)
+```
+
+### Parameters
+
+- `other`
+  - : A string, an object, or a {{jsxref("Temporal.PlainTime")}} instance representing a time to subtract this time from. It is converted to a `Temporal.PlainTime` object using the same algorithm as {{jsxref("Temporal/PlainTime/from", "Temporal.PlainTime.from()")}}. It must have the same calendar as `this`.
+- `options` {{optional_inline}}
+  - : The same options as [`since()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainTime/since#options).
+
+### Return value
+
+A new {{jsxref("Temporal.Duration")}} object representing the duration from this time _until_ `other`. The duration is positive if `other` is after this time, and negative if before.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown if any of the options is invalid.
+
+## Examples
+
+### Using until()
+
+```js
+const lunchTime = Temporal.PlainTime.from("12:30:00");
+const now = Temporal.Now.plainTimeISO();
+const duration = now.until(lunchTime);
+console.log(`It will be ${duration.toLocaleString("en-US")} until lunch`);
+// Example output: "It will be 3 hr, 42 min, 21 sec, 343 ms, 131 μs, 718 ns until lunch"
+```
+
+For more examples, see [`since()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainTime/since).
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainTime")}}
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/PlainTime/add", "Temporal.PlainTime.prototype.add()")}}
+- {{jsxref("Temporal/PlainTime/subtract", "Temporal.PlainTime.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainTime/since", "Temporal.PlainTime.prototype.since()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/valueof/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/valueof/index.md
new file mode 100644
index 000000000000000..5d9781b941f3748
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/valueof/index.md
@@ -0,0 +1,66 @@
+---
+title: Temporal.PlainTime.prototype.valueOf()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainTime/valueOf
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainTime.valueOf
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`valueOf()`** method of {{jsxref("Temporal.PlainTime")}} instances throws a {{jsxref("TypeError")}}, which prevents `Temporal.PlainTime` instances from being [implicitly converted to primitives](/en-US/docs/Web/JavaScript/Data_structures#primitive_coercion) when used in arithmetic or comparison operations.
+
+## Syntax
+
+```js-nolint
+valueOf()
+```
+
+### Parameters
+
+None.
+
+### Return value
+
+None.
+
+### Exceptions
+
+- {{jsxref("TypeError")}}
+  - : Always thrown.
+
+## Description
+
+Because both [primitive conversion](/en-US/docs/Web/JavaScript/Data_structures#primitive_coercion) and [number conversion](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number#number_coercion) call `valueOf()` before `toString()`, if `valueOf()` is absent, then an expression like `time1 > time2` would implicitly compare them as strings, which may have unexpected results. By throwing a `TypeError`, `Temporal.PlainTime` instances prevent such implicit conversions. You need to explicitly convert them to strings using {{jsxref("Temporal/PlainTime/toString", "Temporal.PlainTime.prototype.toString()")}}, or use the {{jsxref("Temporal/PlainTime/compare", "Temporal.PlainTime.compare()")}} static method to compare them.
+
+## Examples
+
+### Arithmetic and comparison operations on Temporal.PlainTime
+
+All arithmetic and comparison operations on `Temporal.PlainTime` instances should use the dedicated methods or convert them to primitives explicitly.
+
+```js
+const time1 = Temporal.PlainTime.from("00:00:00");
+const time2 = Temporal.PlainTime.from("12:00:00");
+time1 > time2; // TypeError: can't convert PlainTime to primitive type
+Temporal.PlainTime.compare(time1, time2); // -1
+
+time2 - time1; // TypeError: can't convert PlainTime to primitive type
+time2.since(time1).toString(); // "PT12H"
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainTime")}}
+- {{jsxref("Temporal/PlainTime/toString", "Temporal.PlainTime.prototype.toString()")}}
+- {{jsxref("Temporal/PlainTime/toJSON", "Temporal.PlainTime.prototype.toJSON()")}}
+- {{jsxref("Temporal/PlainTime/toLocaleString", "Temporal.PlainTime.prototype.toLocaleString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/with/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/with/index.md
new file mode 100644
index 000000000000000..e585a364a71cb0b
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plaintime/with/index.md
@@ -0,0 +1,72 @@
+---
+title: Temporal.PlainTime.prototype.with()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainTime/with
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainTime.with
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`with()`** method of {{jsxref("Temporal.PlainTime")}} instances returns a new `Temporal.PlainTime` object representing this time with some fields replaced by new values. Because all `Temporal` objects are designed to be immutable, this method essentially functions as the setter for the time's fields.
+
+## Syntax
+
+```js-nolint
+with(info)
+with(info, options)
+```
+
+### Parameters
+
+- `info`
+  - : An object containing at least one of the properties recognized by {{jsxref("Temporal/PlainTime/from", "Temporal.PlainTime.from()")}}: `hour`, `microsecond`, `millisecond`, `minute`, `nanosecond`, `second`. Unspecified properties use the values from the original time.
+- `options` {{optional_inline}}
+  - : An object containing the following property:
+    - `overflow` {{optional_inline}}
+      - : A string specifying the behavior when a time component is out of range. Possible values are:
+        - `"constrain"` (default)
+          - : The time component is clamped to the valid range.
+        - `"reject"`
+          - : A {{jsxref("RangeError")}} is thrown if the time component is out of range.
+
+### Return value
+
+A new `Temporal.PlainTime` object, where the fields specified in `info` that are not `undefined` are replaced by the corresponding values, and the rest of the fields are copied from the original time.
+
+### Exceptions
+
+- {{jsxref("TypeError")}}
+  - : Thrown in one of the following cases:
+    - `info` is not an object with at least one recognized property or a string.
+    - `options` is not an object or `undefined`.
+- {{jsxref("RangeError")}}
+  - : Thrown if the provided numerical properties are out of range, and `options.overflow` is set to `"reject"`.
+
+## Examples
+
+### Using with()
+
+```js
+const time = Temporal.PlainTime.from("12:34:56.123456789");
+const newTime = time.with({ hour: 23 });
+console.log(newTime.toString()); // '23:34:56.123456789'
+```
+
+For more examples, see the documentation for the individual properties that can be set using `with()`.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainTime")}}
+- {{jsxref("Temporal/PlainTime/from", "Temporal.PlainTime.from()")}}
+- {{jsxref("Temporal/PlainTime/add", "Temporal.PlainTime.prototype.add()")}}
+- {{jsxref("Temporal/PlainTime/subtract", "Temporal.PlainTime.prototype.subtract()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/add/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/add/index.md
new file mode 100644
index 000000000000000..1bceb573447ce8f
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/add/index.md
@@ -0,0 +1,154 @@
+---
+title: Temporal.PlainYearMonth.prototype.add()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainYearMonth/add
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainYearMonth.add
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`add()`** method of {{jsxref("Temporal.PlainYearMonth")}} instances returns a new `Temporal.PlainYearMonth` object representing this year-month moved forward by a given duration (in a form convertible by {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}).
+
+## Syntax
+
+```js-nolint
+add(duration)
+add(duration, options)
+```
+
+### Parameters
+
+- `duration`
+  - : A string, an object, or a {{jsxref("Temporal.Duration")}} instance representing a duration to add to this year-month. It is converted to a `Temporal.Duration` object using the same algorithm as {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}.
+- `options` {{optional_inline}}
+  - : An object containing the following property:
+    - `overflow` {{optional_inline}}
+      - : A string specifying the behavior when a date component is out of range. Possible values are:
+        - `"constrain"` (default)
+          - : The date component is [clamped](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate#invalid_date_clamping) to the valid range.
+        - `"reject"`
+          - : A {{jsxref("RangeError")}} is thrown if the date component is out of range.
+
+### Return value
+
+A new `Temporal.PlainYearMonth` object representing the year-month specified by the original `PlainYearMonth`, plus the duration.
+
+## Description
+
+The `duration` is handled in this way:
+
+- Move forward by the number of years, keeping the `monthCode` the same. If the `monthCode` is invalid in the resulting year (impossible for Gregorian and ISO 8601, but possible for calendars with leap months), we adjust based on the `overflow` option: for `constrain`, we pick another month according to the cultural conventions of that calendar's users. For example, because the leap month is usually thought of as a duplicate of another month, we may pick the month that it is a duplicate of.
+- Move forward by the number of months, adjusting the year if necessary.
+- For all units smaller than `months` (weeks, days, hours, minutes, seconds, milliseconds, microseconds, nanoseconds), they are converted to the number of days. All commonly supported calendars use fixed-length weeks, so the number of weeks is just converted to the number of days. If the rule is more complex, we may take an approach similar to shifting months. Then, we move forward by that number of days, starting on the first day of the month, adjusting the month and year if necessary. Durations smaller than the current month's length therefore have no effect.
+
+The internal reference day is then chosen to be the first valid day of the month, irrespective of the original reference day or the number of days in the duration. For the Gregorian calendar, overflow cannot happen because every year always has 12 months, and any increment less than a month is just ignored.
+
+Adding a duration is equivalent to [subtracting](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainYearMonth/subtract) its [negation](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration/negated).
+
+## Examples
+
+### Adding a duration in ISO 8601 calendar
+
+```js
+const start = Temporal.PlainYearMonth.from("2021-01");
+const end = start.add({ years: 1, months: 2, weeks: 3, days: 4 });
+console.log(end.toString()); // 2022-03
+
+const end2 = start.add({ years: -1, months: -2, weeks: -3, days: -4 });
+console.log(end2.toString()); // 2019-11
+
+const distance = Temporal.PlainYearMonth.from("2020-01").until("2021-01"); // 366 days
+const end3 = start.add(distance);
+console.log(end3.toString()); // 2022-01
+```
+
+### Adding a duration in a non-ISO calendar
+
+```js
+const start = Temporal.PlainYearMonth.from("2021-02-01[u-ca=chinese]");
+console.log(start.toLocaleString("en-US", { calendar: "chinese" })); // 11/2020
+console.log(start.toString()); // 2021-01-13[u-ca=chinese]
+const end = start.add({ months: 1 });
+console.log(end.toLocaleString("en-US", { calendar: "chinese" })); // 12/2020
+console.log(end.toString()); // 2021-02-12[u-ca=chinese]
+
+// Adding an extra day has no effect at all
+const end2 = start.add({ months: 1, days: 1 });
+console.log(end2.toLocaleString("en-US", { calendar: "chinese" })); // 12/2020
+// The reference day doesn't change, because it's always the first day of the Chinese month
+console.log(end2.toString()); // 2021-02-12[u-ca=chinese]
+
+// Start in a leap month
+const start2 = Temporal.PlainYearMonth.from({
+  year: 5730,
+  monthCode: "M05L",
+  calendar: "hebrew",
+});
+console.log(start2.toLocaleString("en-US", { calendar: "hebrew" })); // Adar I 5730
+// End in another leap month
+const end3 = start2.add({ years: 3 });
+console.log(end3.toLocaleString("en-US", { calendar: "hebrew" })); // Adar I 5733
+```
+
+### Adding a duration with overflow
+
+If we move a few years and the corresponding month is invalid in this year, then we adjust the month based on the `overflow` option.
+
+```js
+// Start in a leap month
+const start = Temporal.PlainYearMonth.from({
+  year: 5730,
+  monthCode: "M05L",
+  calendar: "hebrew",
+});
+// Hebrew leap years occur every 2 or 3 years, and 5731 is not a leap year
+const end = start.add({ years: 1 });
+console.log(end.toLocaleString("en-US", { calendar: "hebrew" })); // Adar 5731
+console.log(end.monthCode); // M06
+console.log(end.toString()); // 1971-02-26[u-ca=hebrew]
+
+// Any further month additions are based on the clamped year-month
+const end2 = start.add({ years: 1, months: 2 });
+console.log(end2.monthCode); // M08
+console.log(end2.toString()); // 1971-04-26[u-ca=hebrew]
+
+// Compare with the same addition in a different order that results in no overflow:
+const end3 = start.add({ months: 2 }).add({ years: 1 });
+console.log(end3.monthCode); // M07
+console.log(end3.toString()); // 1971-03-27[u-ca=hebrew]
+```
+
+Note that the following is not an overflow because the year can just increment:
+
+```js
+const start = Temporal.PlainYearMonth.from("2021-01");
+const end = start.add({ months: 100 });
+console.log(end.toString()); // 2029-05
+```
+
+You can also throw an error if the date component is out of range:
+
+```js
+const start = Temporal.PlainYearMonth.from({
+  year: 5730,
+  monthCode: "M05L",
+  calendar: "hebrew",
+});
+const end = start.add({ years: 1 }, { overflow: "reject" }); // RangeError: invalid "monthCode" calendar field: M05L
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainYearMonth")}}
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/PlainYearMonth/subtract", "Temporal.PlainYearMonth.prototype.subtract()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/calendarid/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/calendarid/index.md
new file mode 100644
index 000000000000000..0ec08013b25b811
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/calendarid/index.md
@@ -0,0 +1,57 @@
+---
+title: Temporal.PlainYearMonth.prototype.calendarId
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainYearMonth/calendarId
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainYearMonth.calendarId
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`calendarId`** accessor property of {{jsxref("Temporal.PlainYearMonth")}} instances returns a string representing the [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars) used to interpret the internal ISO 8601 date.
+
+For a list of commonly supported values, see {{jsxref("Intl/Locale/getCalendars", "Intl.Locale.prototype.getCalendars()")}}.
+
+The set accessor of `calendarId` is `undefined`. You cannot change this property directly. There's no obvious way to create a new `Temporal.PlainYearMonth` object with a different calendar that represents the same year-month, so you need to convert it to a {{jsxref("Temporal.PlainDate")}} object first using {{jsxref("Temporal/PlainYearMonth/toPlainDate", "toPlainDate()")}}, change the calendar, and then convert it back.
+
+## Examples
+
+### Using calendarId
+
+```js
+const ym = Temporal.PlainYearMonth.from("2021-07");
+console.log(ym.calendarId); // "iso8601"; default
+
+const ym2 = Temporal.PlainYearMonth.from("2021-07-01[u-ca=chinese]");
+console.log(ym2.calendarId); // "chinese"
+```
+
+### Changing calendarId
+
+```js
+const ym = Temporal.PlainYearMonth.from("2021-07");
+const newYM = ym
+  .toPlainDate({ day: 1 })
+  .withCalendar("chinese")
+  .toPlainYearMonth();
+console.log(newYM.year, newYM.monthCode); // 2021 "M05"
+
+const newYM2 = ym
+  .toPlainDate({ day: 31 })
+  .withCalendar("chinese")
+  .toPlainYearMonth();
+console.log(newYM2.year, newYM2.monthCode); // 2021 "M06"
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainYearMonth")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/compare/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/compare/index.md
new file mode 100644
index 000000000000000..10a243aec3af96a
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/compare/index.md
@@ -0,0 +1,98 @@
+---
+title: Temporal.PlainYearMonth.compare()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainYearMonth/compare
+page-type: javascript-static-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainYearMonth.compare
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.PlainYearMonth.compare()`** static method returns a number (-1, 0, or 1) indicating whether the first year-month comes before, is the same as, or comes after the second year-month. It is equivalent to comparing their underlying ISO 8601 dates. Two year-months from different calendars may be considered equal if they start on the same ISO date.
+
+> **Note:** `PlainYearMonth` objects keep track of a reference ISO day, which is also used in the comparison. This day is automatically set when using the {{jsxref("Temporal/PlainYearMonth/from", "Temporal.PlainYearMonth.from()")}} method, but can be set manually using the {{jsxref("Temporal/PlainYearMonth/PlainYearMonth", "Temporal.PlainYearMonth()")}} constructor, causing two equivalent year-months to be considered different if they have different reference days. For this reason, you should avoid using the constructor directly and prefer the `from()` method.
+
+## Syntax
+
+```js-nolint
+Temporal.PlainYearMonth.compare(yearMonth1, yearMonth2)
+```
+
+### Parameters
+
+- `yearMonth1`
+  - : A string, an object, or a {{jsxref("Temporal.PlainYearMonth")}} instance representing the first year-month to compare. It is converted to a `Temporal.PlainYearMonth` object using the same algorithm as {{jsxref("Temporal/PlainYearMonth/from", "Temporal.PlainYearMonth.from()")}}.
+- `yearMonth2`
+  - : The second year-month to compare, converted to a `Temporal.PlainYearMonth` object using the same algorithm as `yearMonth1`.
+
+### Return value
+
+Returns `-1` if `yearMonth1` comes before `yearMonth2`, `0` if they are the same, and `1` if `yearMonth2` comes after. They are compared by their underlying date values, ignoring their calendars.
+
+## Examples
+
+### Using Temporal.PlainYearMonth.compare()
+
+```js
+const ym1 = Temporal.PlainYearMonth.from("2021-08");
+const ym2 = Temporal.PlainYearMonth.from("2021-09");
+console.log(Temporal.PlainYearMonth.compare(ym1, ym2)); // -1
+
+const ym3 = Temporal.PlainYearMonth.from("2021-07");
+console.log(Temporal.PlainYearMonth.compare(ym1, ym3)); // 1
+```
+
+### Comparing year-months in different calendars
+
+```js
+const ym1 = Temporal.PlainYearMonth.from({ year: 2021, month: 8 });
+const ym2 = Temporal.PlainYearMonth.from({
+  year: 2021,
+  month: 8,
+  calendar: "islamic",
+});
+const ym3 = Temporal.PlainYearMonth.from({
+  year: 2021,
+  month: 8,
+  calendar: "hebrew",
+});
+console.log(ym1.toString()); // "2021-08"
+console.log(ym2.toString()); // "2582-12-18[u-ca=islamic]"
+console.log(ym3.toString()); // "-001739-04-06[u-ca=hebrew]"
+console.log(Temporal.PlainYearMonth.compare(ym1, ym2)); // -1
+console.log(Temporal.PlainYearMonth.compare(ym1, ym3)); // 1
+```
+
+### Sorting an array of year-months
+
+The purpose of this `compare()` function is to act as a comparator to be passed to {{jsxref("Array.prototype.sort()")}} and related functions.
+
+```js
+const months = [
+  Temporal.PlainYearMonth.from({ year: 2021, month: 8 }),
+  Temporal.PlainYearMonth.from({
+    year: 2021,
+    month: 8,
+    calendar: "islamic",
+  }),
+  Temporal.PlainYearMonth.from({ year: 2021, month: 8, calendar: "hebrew" }),
+];
+
+months.sort(Temporal.PlainYearMonth.compare);
+console.log(months.map((d) => d.toString()));
+// [ "-001739-04-06[u-ca=hebrew]", "2021-08", "2582-12-18[u-ca=islamic]" ]
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainYearMonth")}}
+- {{jsxref("Temporal/PlainYearMonth/equals", "Temporal.PlainYearMonth.prototype.equals()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/daysinmonth/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/daysinmonth/index.md
new file mode 100644
index 000000000000000..ba41b1405a21afb
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/daysinmonth/index.md
@@ -0,0 +1,44 @@
+---
+title: Temporal.PlainYearMonth.prototype.daysInMonth
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainYearMonth/daysInMonth
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainYearMonth.daysInMonth
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`daysInMonth`** accessor property of {{jsxref("Temporal.PlainYearMonth")}} instances returns a positive integer representing the number of days in the month of this date. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+The set accessor of `daysInMonth` is `undefined`. You cannot change this property directly.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/daysInMonth", "Temporal.PlainDate.prototype.daysInMonth")}}.
+
+## Examples
+
+### Using daysInMonth
+
+```js
+const ym = Temporal.PlainYearMonth.from("2021-07");
+console.log(ym.daysInMonth); // 31
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainYearMonth")}}
+- {{jsxref("Temporal/PlainYearMonth/with", "Temporal.PlainYearMonth.prototype.with()")}}
+- {{jsxref("Temporal/PlainYearMonth/add", "Temporal.PlainYearMonth.prototype.add()")}}
+- {{jsxref("Temporal/PlainYearMonth/subtract", "Temporal.PlainYearMonth.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainYearMonth/year", "Temporal.PlainYearMonth.prototype.year")}}
+- {{jsxref("Temporal/PlainYearMonth/month", "Temporal.PlainYearMonth.prototype.month")}}
+- {{jsxref("Temporal/PlainYearMonth/daysInYear", "Temporal.PlainYearMonth.prototype.daysInYear")}}
+- {{jsxref("Temporal/PlainDate/daysInMonth", "Temporal.PlainDate.prototype.daysInMonth")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/daysinyear/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/daysinyear/index.md
new file mode 100644
index 000000000000000..7a18c0fd8d325a5
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/daysinyear/index.md
@@ -0,0 +1,43 @@
+---
+title: Temporal.PlainYearMonth.prototype.daysInYear
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainYearMonth/daysInYear
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainYearMonth.daysInYear
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`daysInYear`** accessor property of {{jsxref("Temporal.PlainYearMonth")}} instances returns a positive integer representing the number of days in the year of this date. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+The set accessor of `daysInYear` is `undefined`. You cannot change this property directly.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/daysInYear", "Temporal.PlainDate.prototype.daysInYear")}}.
+
+## Examples
+
+### Using daysInYear
+
+```js
+const ym = Temporal.PlainYearMonth.from("2021-07");
+console.log(ym.daysInYear); // 365
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainYearMonth")}}
+- {{jsxref("Temporal/PlainYearMonth/with", "Temporal.PlainYearMonth.prototype.with()")}}
+- {{jsxref("Temporal/PlainYearMonth/add", "Temporal.PlainYearMonth.prototype.add()")}}
+- {{jsxref("Temporal/PlainYearMonth/subtract", "Temporal.PlainYearMonth.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainYearMonth/year", "Temporal.PlainYearMonth.prototype.year")}}
+- {{jsxref("Temporal/PlainYearMonth/daysInMonth", "Temporal.PlainYearMonth.prototype.daysInMonth")}}
+- {{jsxref("Temporal/PlainDate/daysInYear", "Temporal.PlainDate.prototype.daysInYear")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/equals/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/equals/index.md
new file mode 100644
index 000000000000000..660404fb65f9a66
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/equals/index.md
@@ -0,0 +1,58 @@
+---
+title: Temporal.PlainYearMonth.prototype.equals()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainYearMonth/equals
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainYearMonth.equals
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`equals()`** method of {{jsxref("Temporal.PlainYearMonth")}} instances returns `true` if this year-month is equivalent in value to another year-month (in a form convertible by {{jsxref("Temporal/PlainYearMonth/from", "Temporal.PlainYearMonth.from()")}}), and `false` otherwise. They are compared both by their underlying ISO date values and their calendars, so two year-months from different calendars may be considered equal by {{jsxref("Temporal/PlainYearMonth/compare", "Temporal.PlainYearMonth.compare()")}} but not by `equals()`.
+
+> **Note:** `PlainYearMonth` objects keep track of a reference ISO day, which is also used in the comparison. This day is automatically set when using the {{jsxref("Temporal/PlainYearMonth/from", "Temporal.PlainYearMonth.from()")}} method, but can be set manually using the {{jsxref("Temporal/PlainYearMonth/PlainYearMonth", "Temporal.PlainYearMonth()")}} constructor, causing two equivalent year-months to be considered different if they have different reference days. For this reason, you should avoid using the constructor directly and prefer the `from()` method.
+
+## Syntax
+
+```js-nolint
+equals(other)
+```
+
+### Parameters
+
+- `other`
+  - : A string, an object, or a {{jsxref("Temporal.PlainYearMonth")}} instance representing the other year-month to compare. It is converted to a `Temporal.PlainYearMonth` object using the same algorithm as {{jsxref("Temporal/PlainYearMonth/from", "Temporal.PlainYearMonth.from()")}}.
+
+### Return value
+
+`true` if this year-month is equal to `other` both in their date value and their calendar, `false` otherwise.
+
+## Examples
+
+### Using equals()
+
+```js
+const ym1 = Temporal.PlainYearMonth.from("2021-08");
+const ym2 = Temporal.PlainYearMonth.from({ year: 2021, month: 8 });
+console.log(ym1.equals(ym2)); // true
+
+const ym3 = Temporal.PlainYearMonth.from("2021-08-01[u-ca=japanese]");
+console.log(ym1.equals(ym3)); // false
+
+const ym4 = Temporal.PlainYearMonth.from("2021-09");
+console.log(ym1.equals(ym4)); // false
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainYearMonth")}}
+- {{jsxref("Temporal/PlainYearMonth/compare", "Temporal.PlainYearMonth.compare()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/era/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/era/index.md
new file mode 100644
index 000000000000000..b63cb4af63843ef
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/era/index.md
@@ -0,0 +1,46 @@
+---
+title: Temporal.PlainYearMonth.prototype.era
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainYearMonth/era
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainYearMonth.era
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`era`** accessor property of {{jsxref("Temporal.PlainYearMonth")}} instances returns a calendar-specific lowercase string representing the era of this year-month, or `undefined` if the calendar does not use eras (e.g. ISO 8601). `era` and `eraYear` together uniquely identify a year in a calendar, in the same way that `year` does. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+The set accessor of `era` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/PlainYearMonth/with", "with()")}} method to create a new `Temporal.PlainYearMonth` object with the desired new value.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/era", "Temporal.PlainDate.prototype.era")}}.
+
+## Examples
+
+### Using era
+
+```js
+const ym = Temporal.PlainYearMonth.from("2021-07"); // ISO 8601 calendar
+console.log(ym.era); // undefined
+
+const ym2 = Temporal.PlainYearMonth.from("2021-07-01[u-ca=gregory]");
+console.log(ym2.era); // gregory
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainYearMonth")}}
+- {{jsxref("Temporal/PlainYearMonth/with", "Temporal.PlainYearMonth.prototype.with()")}}
+- {{jsxref("Temporal/PlainYearMonth/add", "Temporal.PlainYearMonth.prototype.add()")}}
+- {{jsxref("Temporal/PlainYearMonth/subtract", "Temporal.PlainYearMonth.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainYearMonth/year", "Temporal.PlainYearMonth.prototype.year")}}
+- {{jsxref("Temporal/PlainYearMonth/eraYear", "Temporal.PlainYearMonth.prototype.eraYear")}}
+- {{jsxref("Temporal/PlainDate/era", "Temporal.PlainDate.prototype.era")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/erayear/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/erayear/index.md
new file mode 100644
index 000000000000000..138bb30c8980781
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/erayear/index.md
@@ -0,0 +1,52 @@
+---
+title: Temporal.PlainYearMonth.prototype.eraYear
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainYearMonth/eraYear
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainYearMonth.eraYear
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`eraYear`** accessor property of {{jsxref("Temporal.PlainYearMonth")}} instances returns a non-negative integer representing the year of this year-month within the era, or `undefined` if the calendar does not use eras (e.g. ISO 8601). The year index usually starts from 1 (more common) or 0, and years in an era can decrease with time (e.g. Gregorian BCE). `era` and `eraYear` together uniquely identify a year in a calendar, in the same way that `year` does. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+The set accessor of `eraYear` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/PlainYearMonth/with", "with()")}} method to create a new `Temporal.PlainYearMonth` object with the desired new value.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/eraYear", "Temporal.PlainDate.prototype.eraYear")}}.
+
+## Examples
+
+### Using eraYear
+
+```js
+const ym = Temporal.PlainYearMonth.from("2021-07"); // ISO 8601 calendar
+console.log(ym.eraYear); // undefined
+
+const ym2 = Temporal.PlainYearMonth.from("2021-07-01[u-ca=gregory]");
+console.log(ym2.eraYear); // 2021
+
+const ym3 = Temporal.PlainYearMonth.from("-002021-07-01[u-ca=gregory]");
+console.log(ym3.eraYear); // 2022; 0000 is used for the year 1 BC
+
+const ym4 = Temporal.PlainYearMonth.from("2021-07-01[u-ca=japanese]");
+console.log(ym4.eraYear); // 3
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainYearMonth")}}
+- {{jsxref("Temporal/PlainYearMonth/with", "Temporal.PlainYearMonth.prototype.with()")}}
+- {{jsxref("Temporal/PlainYearMonth/add", "Temporal.PlainYearMonth.prototype.add()")}}
+- {{jsxref("Temporal/PlainYearMonth/subtract", "Temporal.PlainYearMonth.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainYearMonth/year", "Temporal.PlainYearMonth.prototype.year")}}
+- {{jsxref("Temporal/PlainYearMonth/era", "Temporal.PlainYearMonth.prototype.era")}}
+- {{jsxref("Temporal/PlainDate/eraYear", "Temporal.PlainDate.prototype.eraYear")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/from/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/from/index.md
new file mode 100644
index 000000000000000..20d23a3ae7034b3
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/from/index.md
@@ -0,0 +1,139 @@
+---
+title: Temporal.PlainYearMonth.from()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainYearMonth/from
+page-type: javascript-static-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainYearMonth.from
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.PlainYearMonth.from()`** static method creates a new `Temporal.PlainYearMonth` object from another `Temporal.PlainYearMonth` object, an object with year and month properties, or an [RFC 9557](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainYearMonth#rfc_9557_format) string.
+
+## Syntax
+
+```js-nolint
+Temporal.PlainYearMonth.from(info)
+Temporal.PlainYearMonth.from(info, options)
+```
+
+### Parameters
+
+- `info`
+
+  - : One of the following:
+
+    - A {{jsxref("Temporal.PlainYearMonth")}} instance, which creates a copy of the instance.
+    - An [RFC 9557](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainYearMonth#rfc_9557_format) string containing a date and optionally a calendar. If the calendar is not `iso8601`, a day is required.
+    - An object containing the following properties (in the order they are retrieved and validated):
+      - `calendar` {{optional_inline}}
+        - : A string that corresponds to the {{jsxref("Temporal/PlainYearMonth/calendarId", "calendarId")}} property. Defaults to `"iso8601"`. All other properties are interpreted in this calendar system (unlike the {{jsxref("Temporal/PlainYearMonth/PlainYearMonth", "Temporal.PlainYearMonth()")}} constructor, which interprets the values in the ISO calendar system).
+      - `era` and `eraYear`
+        - : A string and an integer that correspond to the {{jsxref("Temporal/PlainYearMonth/era", "era")}} and {{jsxref("Temporal/PlainYearMonth/eraYear", "eraYear")}} properties. Are only used if the calendar system has eras. `era` and `eraYear` must be provided simultaneously. If they are not provided, then `year` must be provided. If all of `era`, `eraYear`, and `year` are provided, they must be consistent.
+      - `month`
+        - : Corresponds to the {{jsxref("Temporal/PlainYearMonth/month", "month")}} property. Must be positive regardless of the `overflow` option.
+      - `monthCode`
+        - : Corresponds to the {{jsxref("Temporal/PlainYearMonth/monthCode", "monthCode")}} property. If it is not provided, then `month` must be provided. If both `month` and `monthCode` are provided, they must be consistent.
+      - `year`
+        - : Corresponds to the {{jsxref("Temporal/PlainYearMonth/year", "year")}} property.
+
+- `options` {{optional_inline}}
+  - : An object containing the following property:
+    - `overflow` {{optional_inline}}
+      - : A string specifying the behavior when a date component is out of range (when using the object `info`). Possible values are:
+        - `"constrain"` (default)
+          - : The date component is [clamped](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate#invalid_date_clamping) to the valid range.
+        - `"reject"`
+          - : A {{jsxref("RangeError")}} is thrown if the date component is out of range.
+
+### Return value
+
+A new `Temporal.PlainYearMonth` object, representing the year and month specified by `info` in the specified `calendar`.
+
+Each `PlainYearMonth` stores a whole ISO 8601 date internally, which has the same year-month in the target calendar as what's exposed. The reference day is visible when stringifying with {{jsxref("Temporal/PlainYearMonth/toString", "toString()")}}, which outputs an ISO date. The reference day is chosen arbitrarily but consistently; that is, every `(year, month)` pair always maps to the same ISO reference day. It does not use the day provided in the input. Instead, the reference day is always chosen to be the first valid day of the month.
+
+This reference day canonicalization ensures that {{jsxref("Temporal/PlainYearMonth/equals", "equals()")}} can directly compare the underlying ISO dates without extra computation.
+
+### Exceptions
+
+- {{jsxref("TypeError")}}
+  - : Thrown in one of the following cases:
+    - `info` is not an object or a string.
+    - `options` is not an object or `undefined`.
+    - The provided properties are insufficient to unambiguously determine a date. You usually need to provide a `year` (or `era` and `eraYear`) and a `month` (or a `monthCode`).
+- {{jsxref("RangeError")}}
+  - : Thrown in one of the following cases:
+    - The provided properties that specify the same component are inconsistent.
+    - The provided non-numerical properties are not valid; for example, if `monthCode` is never a valid month code in this calendar.
+    - The provided numerical properties are out of range, and `options.overflow` is set to `"reject"`.
+
+## Examples
+
+### Creating a PlainYearMonth from an object
+
+```js
+// Year + month code
+const ym = Temporal.PlainYearMonth.from({ year: 2021, monthCode: "M05" });
+console.log(ym.toString()); // 2021-05
+
+// Year + month
+const ym2 = Temporal.PlainYearMonth.from({ year: 2021, month: 7 });
+console.log(ym2.toString()); // 2021-07
+
+// Year + month in a different calendar
+const ym3 = Temporal.PlainYearMonth.from({
+  year: 5730,
+  month: 6,
+  calendar: "hebrew",
+});
+console.log(ym3.toString()); // 1970-02-07[u-ca=hebrew]
+
+// Year + month code in a different calendar
+const ym4 = Temporal.PlainYearMonth.from({
+  year: 5730,
+  monthCode: "M05L",
+  calendar: "hebrew",
+});
+console.log(ym4.toString()); // 1970-02-07[u-ca=hebrew]
+```
+
+### Controlling overflow behavior
+
+By default, out-of-range values are clamped to the valid range.
+
+```js
+const ym1 = Temporal.PlainYearMonth.from({ year: 2021, month: 13 });
+console.log(ym1.toString()); // 2021-12
+
+// 5732 is not a Hebrew leap year, so a different monthCode is chosen
+const ym2 = Temporal.PlainYearMonth.from({
+  year: 5732,
+  monthCode: "M05L",
+  calendar: "hebrew",
+});
+console.log(ym2.toLocaleString("en-US", { calendar: "hebrew" })); // Adar 5732
+const underlyingDate = Temporal.PlainDate.from(ym2.toString());
+console.log(underlyingDate.year, underlyingDate.monthCode); // 5732 M06
+```
+
+You can change this behavior to throw an error instead:
+
+```js
+Temporal.PlainYearMonth.from({ year: 2021, month: 13 }, { overflow: "reject" });
+// RangeError: date value "month" not in 1..12: 13
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainYearMonth")}}
+- {{jsxref("Temporal/PlainYearMonth/PlainYearMonth", "Temporal.PlainYearMonth()")}}
+- {{jsxref("Temporal/PlainYearMonth/with", "Temporal.PlainYearMonth.prototype.with()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/index.md
new file mode 100644
index 000000000000000..e38091b26bcd56e
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/index.md
@@ -0,0 +1,117 @@
+---
+title: Temporal.PlainYearMonth
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainYearMonth
+page-type: javascript-class
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainYearMonth
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.PlainYearMonth`** object represents the year and month of a calendar date, without a day or time zone; for example, an event on a calendar that happens during the whole month. It is fundamentally represented as an ISO 8601 calendar date, with year, month, and day fields, and an associated calendar system. The day is used to disambiguate the year-month in non-ISO calendar systems.
+
+## Description
+
+A `PlainYearMonth` is essentially the year-month part of a {{jsxref("Temporal.PlainDate")}} object, without the day.
+
+### RFC 9557 format
+
+`PlainYearMonth` objects can be serialized and parsed using the [RFC 9557](https://datatracker.ietf.org/doc/html/rfc9557) format, an extension to the [ISO 8601 / RFC 3339](https://datatracker.ietf.org/doc/html/rfc3339) format. The string has the following form (spaces are only for readability and should not be present in the actual string):
+
+```plain
+YYYY-MM-DD [u-ca=calendar_id]
+```
+
+- `YYYY`
+  - : Either a four-digit number, or a six-digit number with a `+` or `-` sign.
+- `MM`
+  - : A two-digit number from `01` to `12`.
+- `DD` {{optional_inline}}
+  - : A two-digit number from `01` to `31`. It is required for non-ISO calendars, and optional otherwise. If omitted, the string looks like `YYYY-MM` or `YYYYMM`. Note that the reference day actually stored may be different from the one you provide, but the represented year-month is the same. See {{jsxref("Temporal/PlainYearMonth/from", "Temporal.PlainYearMonth.from()")}} for more information. The `YYYY`, `MM`, and `DD` components can be separated by `-` or nothing.
+- `[u-ca=calendar_id]` {{optional_inline}}
+  - : Replace `calendar_id` with the calendar to use. May have a _critical flag_ by prefixing the key with `!`: e.g., `[!u-ca=iso8601]`. This flag generally tells other systems that it cannot be ignored if they don't support it. The `Temporal` parser will throw an error if the annotations contain two or more calendar annotations and one of them is critical. Defaults to `[u-ca=iso8601]`. Note that the `YYYY-MM-DD` is always interpreted as an ISO 8601 calendar date and then converted to the specified calendar.
+
+As an input, you may optionally include the time, offset, and time zone identifier, in the same format as [`PlainDateTime`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime#rfc_9557_format), but they will be ignored. Other annotations in the `[key=value]` format are also ignored, and they must not have the critical flag.
+
+When serializing, you can configure whether to display the calendar ID, and whether to add a critical flag for it.
+
+## Constructor
+
+- {{jsxref("Temporal/PlainYearMonth/PlainYearMonth", "Temporal.PlainYearMonth()")}} {{experimental_inline}}
+  - : Creates a new `Temporal.PlainYearMonth` object by directly supplying the underlying data.
+
+## Static methods
+
+- {{jsxref("Temporal/PlainYearMonth/compare", "Temporal.PlainYearMonth.compare()")}} {{experimental_inline}}
+  - : Returns a number (-1, 0, or 1) indicating whether the first year-month comes before, is the same as, or comes after the second year-month. Equivalent to comparing their underlying ISO 8601 dates. Two year-months from different calendars may be considered equal if they start on the same ISO date.
+- {{jsxref("Temporal/PlainYearMonth/from", "Temporal.PlainYearMonth.from()")}} {{experimental_inline}}
+  - : Creates a new `Temporal.PlainYearMonth` object from another `Temporal.PlainYearMonth` object, an object with year and month properties, or an [RFC 9557](#rfc_9557_format) string.
+
+## Instance properties
+
+These properties are defined on `Temporal.PlainYearMonth.prototype` and shared by all `Temporal.PlainYearMonth` instances.
+
+- {{jsxref("Temporal/PlainYearMonth/calendarId", "Temporal.PlainYearMonth.prototype.calendarId")}} {{experimental_inline}}
+  - : Returns a string representing the [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars) used to interpret the internal ISO 8601 date.
+- {{jsxref("Object/constructor", "Temporal.PlainYearMonth.prototype.constructor")}}
+  - : The constructor function that created the instance object. For `Temporal.PlainYearMonth` instances, the initial value is the {{jsxref("Temporal/PlainYearMonth/PlainYearMonth", "Temporal.PlainYearMonth()")}} constructor.
+- {{jsxref("Temporal/PlainYearMonth/daysInMonth", "Temporal.PlainYearMonth.prototype.daysInMonth")}} {{experimental_inline}}
+  - : Returns a positive integer representing the number of days in the month of this date. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+- {{jsxref("Temporal/PlainYearMonth/daysInYear", "Temporal.PlainYearMonth.prototype.daysInYear")}} {{experimental_inline}}
+  - : Returns a positive integer representing the number of days in the year of this date. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. For the ISO 8601 calendar, this is 365, or 366 in a leap year.
+- {{jsxref("Temporal/PlainYearMonth/era", "Temporal.PlainYearMonth.prototype.era")}} {{experimental_inline}}
+  - : Returns a calendar-specific lowercase string representing the era of this year-month, or `undefined` if the calendar does not use eras (e.g. ISO 8601). `era` and `eraYear` together uniquely identify a year in a calendar, in the same way that `year` does. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. For Gregorian, it is either `"gregory"` or `"gregory-inverse"`.
+- {{jsxref("Temporal/PlainYearMonth/eraYear", "Temporal.PlainYearMonth.prototype.eraYear")}} {{experimental_inline}}
+  - : Returns a non-negative integer representing the year of this year-month within the era, or `undefined` if the calendar does not use eras (e.g. ISO 8601). The year index usually starts from 1 (more common) or 0, and years in an era can decrease with time (e.g. Gregorian BCE). `era` and `eraYear` together uniquely identify a year in a calendar, in the same way that `year` does. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+- {{jsxref("Temporal/PlainYearMonth/inLeapYear", "Temporal.PlainYearMonth.prototype.inLeapYear")}} {{experimental_inline}}
+  - : Returns a boolean indicating whether this year-month is in a leap year. A leap year is a year that has more days (due to a leap day or leap month) than a common year. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+- {{jsxref("Temporal/PlainYearMonth/month", "Temporal.PlainYearMonth.prototype.month")}} {{experimental_inline}}
+  - : Returns a positive integer representing the 1-based month index in the year of this year-month. The first month of this year is `1`, and the last month is the {{jsxref("Temporal/PlainYearMonth/monthsInYear", "monthsInYear")}}. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. Note that unlike {{jsxref("Date.prototype.getMonth()")}}, the index is 1-based. If the calendar has leap months, then the month with the same {{jsxref("Temporal/PlainDate/monthCode", "monthCode")}} may have different `month` indexes for different years.
+- {{jsxref("Temporal/PlainYearMonth/monthCode", "Temporal.PlainYearMonth.prototype.monthCode")}} {{experimental_inline}}
+  - : Returns a calendar-specific string representing the month of this year-month. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. Usually it is `M` plus a two-digit month number. For leap months, it is the previous month's code followed by `L`. If the leap month is the first month of the year, the code is `M00L`.
+- {{jsxref("Temporal/PlainYearMonth/monthsInYear", "Temporal.PlainYearMonth.prototype.monthsInYear")}} {{experimental_inline}}
+  - : Returns a positive integer representing the number of months in the year of this date. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. For the ISO 8601 calendar, this is always 12, but in other calendar systems it may differ.
+- {{jsxref("Temporal/PlainYearMonth/year", "Temporal.PlainYearMonth.prototype.year")}} {{experimental_inline}}
+  - : Returns an integer representing the number of years of this year-month relative to the start of a calendar-specific epoch year. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. Usually year 1 is either the first year of the latest era or the ISO 8601 year `0001`. If the epoch is in the middle of the year, that year will have the same value before and after the start date of the era.
+- `Temporal.PlainYearMonth.prototype[Symbol.toStringTag]`
+  - : The initial value of the [`[Symbol.toStringTag]`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol/toStringTag) property is the string `"Temporal.PlainYearMonth"`. This property is used in {{jsxref("Object.prototype.toString()")}}.
+
+## Instance methods
+
+- {{jsxref("Temporal/PlainYearMonth/add", "Temporal.PlainYearMonth.prototype.add()")}} {{experimental_inline}}
+  - : Returns a new `Temporal.PlainYearMonth` object representing this year-month moved forward by a given duration (in a form convertible by {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}).
+- {{jsxref("Temporal/PlainYearMonth/equals", "Temporal.PlainYearMonth.prototype.equals()")}} {{experimental_inline}}
+  - : Returns `true` if this year-month is equivalent in value to another year-month (in a form convertible by {{jsxref("Temporal/PlainYearMonth/from", "Temporal.PlainYearMonth.from()")}}), and `false` otherwise. They are compared both by their underlying ISO date values and their calendars, so two year-months from different calendars may be considered equal by {{jsxref("Temporal/PlainYearMonth/compare", "Temporal.PlainYearMonth.compare()")}} but not by `equals()`.
+- {{jsxref("Temporal/PlainYearMonth/since", "Temporal.PlainYearMonth.prototype.since()")}} {{experimental_inline}}
+  - : Returns a new {{jsxref("Temporal.Duration")}} object representing the duration from another year-month (in a form convertible by {{jsxref("Temporal/PlainYearMonth/from", "Temporal.PlainYearMonth.from()")}}) to this year-month. The duration is positive if the other month is before this month, and negative if after.
+- {{jsxref("Temporal/PlainYearMonth/subtract", "Temporal.PlainYearMonth.prototype.subtract()")}} {{experimental_inline}}
+  - : Returns a new `Temporal.PlainYearMonth` object representing this year-month moved backward by a given duration (in a form convertible by {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}).
+- {{jsxref("Temporal/PlainYearMonth/toJSON", "Temporal.PlainYearMonth.prototype.toJSON()")}} {{experimental_inline}}
+  - : Returns a string representing this year-month in the same [RFC 9557 format](#rfc_9557_format) as calling {{jsxref("Temporal/PlainYearMonth/toString", "toString()")}}. Intended to be implicitly called by {{jsxref("JSON.stringify()")}}.
+- {{jsxref("Temporal/PlainYearMonth/toLocaleString", "Temporal.PlainYearMonth.prototype.toLocaleString()")}} {{experimental_inline}}
+  - : Returns a string with a language-sensitive representation of this year-month.
+- {{jsxref("Temporal/PlainYearMonth/toPlainDate", "Temporal.PlainYearMonth.prototype.toPlainDate()")}} {{experimental_inline}}
+  - : Returns a new {{jsxref("Temporal.PlainDate")}} object representing this year-month and a supplied day in the same calendar system.
+- {{jsxref("Temporal/PlainYearMonth/toString", "Temporal.PlainYearMonth.prototype.toString()")}} {{experimental_inline}}
+  - : Returns a string representing this year-month in the [RFC 9557 format](#rfc_9557_format).
+- {{jsxref("Temporal/PlainYearMonth/until", "Temporal.PlainYearMonth.prototype.until()")}} {{experimental_inline}}
+  - : Returns a new {{jsxref("Temporal.Duration")}} object representing the duration from this year-month to another year-month (in a form convertible by {{jsxref("Temporal/PlainYearMonth/from", "Temporal.PlainYearMonth.from()")}}). The duration is positive if the other month is after this month, and negative if before.
+- {{jsxref("Temporal/PlainYearMonth/valueOf", "Temporal.PlainYearMonth.prototype.valueOf()")}} {{experimental_inline}}
+  - : Throws a {{jsxref("TypeError")}}, which prevents `Temporal.PlainYearMonth` instances from being [implicitly converted to primitives](/en-US/docs/Web/JavaScript/Data_structures#primitive_coercion) when used in arithmetic or comparison operations.
+- {{jsxref("Temporal/PlainYearMonth/with", "Temporal.PlainYearMonth.prototype.with()")}} {{experimental_inline}}
+  - : Returns a new `Temporal.PlainYearMonth` object representing this year-month with some fields replaced by new values.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal")}}
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal.PlainMonthDay")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/inleapyear/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/inleapyear/index.md
new file mode 100644
index 000000000000000..1c8a05e6b7d087b
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/inleapyear/index.md
@@ -0,0 +1,46 @@
+---
+title: Temporal.PlainYearMonth.prototype.inLeapYear
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainYearMonth/inLeapYear
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainYearMonth.inLeapYear
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`inLeapYear`** accessor property of {{jsxref("Temporal.PlainYearMonth")}} instances returns a boolean indicating whether this year-month is in a leap year. A leap year is a year that has more days (due to a leap day or leap month) than a common year. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+The set accessor of `inLeapYear` is `undefined`. You cannot change this property directly.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/inLeapYear", "Temporal.PlainDate.prototype.inLeapYear")}}.
+
+## Examples
+
+### Using inLeapYear
+
+```js
+const ym = Temporal.PlainYearMonth.from("2021-07");
+console.log(ym.inLeapYear); // false
+console.log(ym.daysInYear); // 365
+console.log(ym.monthsInYear); // 12
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainYearMonth")}}
+- {{jsxref("Temporal/PlainYearMonth/with", "Temporal.PlainYearMonth.prototype.with()")}}
+- {{jsxref("Temporal/PlainYearMonth/add", "Temporal.PlainYearMonth.prototype.add()")}}
+- {{jsxref("Temporal/PlainYearMonth/subtract", "Temporal.PlainYearMonth.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainYearMonth/year", "Temporal.PlainYearMonth.prototype.year")}}
+- {{jsxref("Temporal/PlainYearMonth/daysInYear", "Temporal.PlainYearMonth.prototype.daysInYear")}}
+- {{jsxref("Temporal/PlainYearMonth/monthsInYear", "Temporal.PlainYearMonth.prototype.monthsInYear")}}
+- {{jsxref("Temporal/PlainDate/inLeapYear", "Temporal.PlainDate.prototype.inLeapYear")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/month/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/month/index.md
new file mode 100644
index 000000000000000..a0724dea9777fef
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/month/index.md
@@ -0,0 +1,46 @@
+---
+title: Temporal.PlainYearMonth.prototype.month
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainYearMonth/month
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainYearMonth.month
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`month`** accessor property of {{jsxref("Temporal.PlainYearMonth")}} instances returns a positive integer representing the 1-based month index in the year of this year-month. The first month of this year is `1`, and the last month is the {{jsxref("Temporal/PlainYearMonth/monthsInYear", "monthsInYear")}}. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+The set accessor of `month` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/PlainYearMonth/with", "with()")}} method to create a new `Temporal.PlainYearMonth` object with the desired new value.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/month", "Temporal.PlainDate.prototype.month")}}.
+
+## Examples
+
+### Using month
+
+```js
+const ym = Temporal.PlainYearMonth.from("2021-07"); // ISO 8601 calendar
+console.log(ym.monthCode); // "M07"
+console.log(ym.month); // 7
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainYearMonth")}}
+- {{jsxref("Temporal/PlainYearMonth/with", "Temporal.PlainYearMonth.prototype.with()")}}
+- {{jsxref("Temporal/PlainYearMonth/add", "Temporal.PlainYearMonth.prototype.add()")}}
+- {{jsxref("Temporal/PlainYearMonth/subtract", "Temporal.PlainYearMonth.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainYearMonth/year", "Temporal.PlainYearMonth.prototype.year")}}
+- {{jsxref("Temporal/PlainYearMonth/monthCode", "Temporal.PlainYearMonth.prototype.monthCode")}}
+- {{jsxref("Temporal/PlainYearMonth/daysInMonth", "Temporal.PlainYearMonth.prototype.daysInMonth")}}
+- {{jsxref("Temporal/PlainYearMonth/monthsInYear", "Temporal.PlainYearMonth.prototype.monthsInYear")}}
+- {{jsxref("Temporal/PlainDate/month", "Temporal.PlainDate.prototype.month")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/monthcode/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/monthcode/index.md
new file mode 100644
index 000000000000000..39f5524081b18c1
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/monthcode/index.md
@@ -0,0 +1,48 @@
+---
+title: Temporal.PlainYearMonth.prototype.monthCode
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainYearMonth/monthCode
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainYearMonth.monthCode
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`monthCode`** accessor property of {{jsxref("Temporal.PlainYearMonth")}} instances returns a calendar-specific string representing the month of this year-month. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+Usually it is `M` plus a two-digit month number. For leap months, it is the previous month's code followed by `L` (even if it's conceptually a derivative of the following month; for example, in the Hebrew calendar, Adar I has code `M05L` but Adar II has code `M06`). If the leap month is the first month of the year, the code is `M00L`.
+
+The set accessor of `monthCode` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/PlainYearMonth/with", "with()")}} method to create a new `Temporal.PlainYearMonth` object with the desired new value.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/monthCode", "Temporal.PlainDate.prototype.monthCode")}}.
+
+## Examples
+
+### Using monthCode
+
+```js
+const date = Temporal.PlainYearMonth.from("2021-07-01"); // ISO 8601 calendar
+console.log(date.monthCode); // "M07"
+console.log(date.month); // 7
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainYearMonth")}}
+- {{jsxref("Temporal/PlainYearMonth/with", "Temporal.PlainYearMonth.prototype.with()")}}
+- {{jsxref("Temporal/PlainYearMonth/add", "Temporal.PlainYearMonth.prototype.add()")}}
+- {{jsxref("Temporal/PlainYearMonth/subtract", "Temporal.PlainYearMonth.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainYearMonth/year", "Temporal.PlainYearMonth.prototype.year")}}
+- {{jsxref("Temporal/PlainYearMonth/month", "Temporal.PlainYearMonth.prototype.month")}}
+- {{jsxref("Temporal/PlainYearMonth/daysInMonth", "Temporal.PlainYearMonth.prototype.daysInMonth")}}
+- {{jsxref("Temporal/PlainYearMonth/monthsInYear", "Temporal.PlainYearMonth.prototype.monthsInYear")}}
+- {{jsxref("Temporal/PlainDate/monthCode", "Temporal.PlainDate.prototype.monthCode")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/monthsinyear/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/monthsinyear/index.md
new file mode 100644
index 000000000000000..69992987bfa75e2
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/monthsinyear/index.md
@@ -0,0 +1,45 @@
+---
+title: Temporal.PlainYearMonth.prototype.monthsInYear
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainYearMonth/monthsInYear
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainYearMonth.monthsInYear
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`monthsInYear`** accessor property of {{jsxref("Temporal.PlainYearMonth")}} instances returns a positive integer representing the number of months in the year of this date. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+The set accessor of `monthsInYear` is `undefined`. You cannot change this property directly.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/monthsInYear", "Temporal.PlainDate.prototype.monthsInYear")}}.
+
+## Examples
+
+### Using monthsInYear
+
+```js
+const ym = Temporal.PlainYearMonth.from("2021-07");
+console.log(ym.monthsInYear); // 12
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainYearMonth")}}
+- {{jsxref("Temporal/PlainYearMonth/with", "Temporal.PlainYearMonth.prototype.with()")}}
+- {{jsxref("Temporal/PlainYearMonth/add", "Temporal.PlainYearMonth.prototype.add()")}}
+- {{jsxref("Temporal/PlainYearMonth/subtract", "Temporal.PlainYearMonth.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainYearMonth/year", "Temporal.PlainYearMonth.prototype.year")}}
+- {{jsxref("Temporal/PlainYearMonth/month", "Temporal.PlainYearMonth.prototype.month")}}
+- {{jsxref("Temporal/PlainYearMonth/monthCode", "Temporal.PlainYearMonth.prototype.monthCode")}}
+- {{jsxref("Temporal/PlainYearMonth/daysInMonth", "Temporal.PlainYearMonth.prototype.daysInMonth")}}
+- {{jsxref("Temporal/PlainDate/monthsInYear", "Temporal.PlainDate.prototype.monthsInYear")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/plainyearmonth/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/plainyearmonth/index.md
new file mode 100644
index 000000000000000..f524d5e828257f0
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/plainyearmonth/index.md
@@ -0,0 +1,91 @@
+---
+title: Temporal.PlainYearMonth()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainYearMonth/PlainYearMonth
+page-type: javascript-constructor
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainYearMonth.PlainYearMonth
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.PlainYearMonth()`** constructor creates {{jsxref("Temporal.PlainYearMonth")}} objects.
+
+This constructor allows you to create instances by directly supplying the underlying data. Like all other `Temporal` classes, you should usually construct `Temporal.PlainYearMonth` objects using the {{jsxref("Temporal/PlainYearMonth/from", "Temporal.PlainYearMonth.from()")}} static method, which can handle a variety of input types.
+
+## Syntax
+
+```js-nolint
+new Temporal.PlainYearMonth(year, month)
+new Temporal.PlainYearMonth(year, month, calendar)
+new Temporal.PlainYearMonth(year, month, calendar, referenceDay)
+```
+
+> **Note:** `Temporal.PlainYearMonth()` can only be constructed with [`new`](/en-US/docs/Web/JavaScript/Reference/Operators/new). Attempting to call it without `new` throws a {{jsxref("TypeError")}}.
+
+> [!WARNING]
+> Avoid using the `calendar` and `referenceDay` parameters, because {{jsxref("Temporal/PlainYearMonth/equals", "equals()")}} and {{jsxref("Temporal/PlainYearMonth/compare", "compare()")}} will consider the reference day for comparison, causing two equivalent year-months to be considered different if they have different reference days. To create a `Temporal.PlainYearMonth` object with a non-ISO calendar, use the {{jsxref("Temporal/PlainYearMonth/from", "Temporal.PlainYearMonth.from()")}} static method.
+
+### Parameters
+
+- `year` {{optional_inline}}
+  - : A number, truncated to an integer, representing the year in the ISO calendar system.
+- `month`
+  - : A number, truncated to an integer, representing the month in the ISO calendar system.
+- `calendar` {{optional_inline}}
+  - : A string representing the [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars) to use. Note that irrespective of the `calendar`, the `year`, `month`, and `referenceDay` must be in the ISO 8601 calendar system. Defaults to `"iso8601"`.
+- `referenceDay`
+  - : A number, truncated to an integer, representing the day of the month in the ISO calendar system. Defaults to `1`. The same ISO year-month can represent different months on different days with non-ISO calendars. For example, the days 2021-07-01 and 2021-07-31 may fall in different months in a non-Gregorian calendar, and just specifying "2021-07" is insufficient to unambiguously determine a month in the target calendar. Therefore, you virtually always want to specify a `referenceDay` when using a non-ISO calendar.
+
+### Return value
+
+A new `Temporal.PlainYearMonth` object, representing the year-month of the date specified by `year`, `month`, and `referenceDay` (in the ISO calendar), interpreted in the calendar system specified by `calendar`.
+
+### Exceptions
+
+- {{jsxref("TypeError")}}
+  - : Thrown if `calendar` is not a string or `undefined`.
+- {{jsxref("RangeError")}}
+  - : Thrown in one of the following cases:
+    - `year`, `month`, or `referenceDay` is not a finite number, or do not represent a valid date in the ISO calendar system.
+    - `calendar` is not a valid calendar identifier.
+
+## Examples
+
+### Using Temporal.PlainYearMonth()
+
+```js
+const ym = new Temporal.PlainYearMonth(2021, 7);
+console.log(ym.toString()); // 2021-07
+
+const ym2 = new Temporal.PlainYearMonth(2021, 7, "chinese");
+console.log(ym2.toString()); // 2021-07-01[u-ca=chinese]
+
+const ym3 = new Temporal.PlainYearMonth(2021, 7, "chinese", 31);
+console.log(ym3.toString()); // 2021-07-31[u-ca=chinese]
+```
+
+### Improper usage
+
+You should avoid using the `calendar` and `referenceDay` parameters, unless you know that the `referenceDay` is the canonical reference day that would be selected by `Temporal.PlainYearMonth.from()` for the same year-month.
+
+```js
+const ym = new Temporal.PlainYearMonth(2021, 7, "chinese", 1);
+const ym2 = Temporal.PlainYearMonth.from("2021-07-01[u-ca=chinese]");
+console.log(ym.equals(ym2)); // false
+console.log(ym.toString()); // 2021-07-01[u-ca=chinese]
+console.log(ym2.toString()); // 2021-06-10[u-ca=chinese]
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainYearMonth")}}
+- {{jsxref("Temporal/PlainYearMonth/from", "Temporal.PlainYearMonth.from()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/since/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/since/index.md
new file mode 100644
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--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/since/index.md
@@ -0,0 +1,100 @@
+---
+title: Temporal.PlainYearMonth.prototype.since()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainYearMonth/since
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainYearMonth.since
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`since()`** method of {{jsxref("Temporal.PlainYearMonth")}} instances returns a new {{jsxref("Temporal.Duration")}} object representing the duration from another year-month (in a form convertible by {{jsxref("Temporal/PlainYearMonth/from", "Temporal.PlainYearMonth.from()")}}) to this year-month. The duration is positive if the other month is before this month, and negative if after.
+
+This method does `this - other`. To do `other - this`, use the {{jsxref("Temporal/PlainYearMonth/until", "until()")}} method.
+
+## Syntax
+
+```js-nolint
+since(other)
+since(other, options)
+```
+
+### Parameters
+
+- `other`
+  - : A string, an object, or a {{jsxref("Temporal.PlainYearMonth")}} instance representing a year-month to subtract from this year-month. It is converted to a `Temporal.PlainYearMonth` object using the same algorithm as {{jsxref("Temporal/PlainYearMonth/from", "Temporal.PlainYearMonth.from()")}}. It must have the same calendar as `this`.
+- `options` {{optional_inline}}
+  - : An object containing the options for {{jsxref("Temporal/Duration/round", "Temporal.Duration.prototype.round()")}}, which includes `largestUnit`, `roundingIncrement`, `roundingMode`, and `smallestUnit`. `largestUnit` and `smallestUnit` only accept the units: `"year"`, `"month"`, or their plural forms. For `largestUnit`, the default value `"auto"` means `"year"`. For `smallestUnit`, the default value is `"month"`. The current date is used as the `relativeTo` option.
+
+### Return value
+
+A new {{jsxref("Temporal.Duration")}} object representing the duration _since_ `other` to this year-month. The duration is positive if `other` is before this year-month, and negative if after.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown in one of the following cases:
+    - `other` has a different calendar than `this`.
+    - Any of the options is invalid.
+
+## Examples
+
+### Using since()
+
+```js
+const lastUpdated = Temporal.PlainYearMonth.from("2022-01");
+const now = Temporal.Now.plainDateISO().toPlainYearMonth();
+const duration = now.since(lastUpdated);
+console.log(`Last updated ${duration.toLocaleString("en-US")} ago`);
+// Expected output: "Last updated [number] years, [number] months ago"
+
+const duration2 = now.since(lastUpdated, { largestUnit: "month" });
+console.log(`Last updated ${duration2.toLocaleString("en-US")} ago`);
+// Expected output: "Last updated [number] months ago"
+
+const duration3 = now.since(lastUpdated, { smallestUnit: "year" });
+console.log(`Last updated ${duration3.toLocaleString("en-US")} ago`);
+// Expected output: "Last updated [number] years ago"
+```
+
+### Rounding the result
+
+By default the fractional part of the `smallestUnit` is truncated. You can round it up using the `roundingIncrement` and `roundingMode` options.
+
+```js
+const ym1 = Temporal.PlainYearMonth.from("2022-01");
+const ym2 = Temporal.PlainYearMonth.from("2022-11");
+const duration = ym2.since(ym1, {
+  smallestUnit: "year",
+  roundingMode: "ceil",
+});
+console.log(duration.toString()); // "P1Y"
+```
+
+### Getting the result in days
+
+By default, the resulting duration never contains days, because `PlainYearMonth` does not offer day-level precision. You can get the result in days by converting it to a {{jsxref("Temporal.PlainDate")}} first with an unambiguous day.
+
+```js
+const ym1 = Temporal.PlainYearMonth.from("2022-01");
+const ym2 = Temporal.PlainYearMonth.from("2022-11");
+const duration = ym2.toPlainDate({ day: 1 }).since(ym1.toPlainDate({ day: 1 }));
+console.log(duration.toString()); // "P304D"
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainYearMonth")}}
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/PlainYearMonth/add", "Temporal.PlainYearMonth.prototype.add()")}}
+- {{jsxref("Temporal/PlainYearMonth/subtract", "Temporal.PlainYearMonth.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainYearMonth/until", "Temporal.PlainYearMonth.prototype.until()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/subtract/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/subtract/index.md
new file mode 100644
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--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/subtract/index.md
@@ -0,0 +1,70 @@
+---
+title: Temporal.PlainYearMonth.prototype.subtract()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainYearMonth/subtract
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainYearMonth.subtract
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`subtract()`** method of {{jsxref("Temporal.PlainYearMonth")}} instances returns a new `Temporal.PlainYearMonth` object representing this year-month moved backward by a given duration (in a form convertible by {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}).
+
+If you want to subtract two year-months and get a duration, use {{jsxref("Temporal/PlainYearMonth/since", "since()")}} or {{jsxref("Temporal/PlainYearMonth/until", "until()")}} instead.
+
+## Syntax
+
+```js-nolint
+subtract(duration)
+subtract(duration, options)
+```
+
+### Parameters
+
+- `duration`
+  - : A string, an object, or a {{jsxref("Temporal.Duration")}} instance representing a duration to subtract from this year-month. It is converted to a `Temporal.Duration` object using the same algorithm as {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}.
+- `options` {{optional_inline}}
+  - : An object containing the following property:
+    - `overflow` {{optional_inline}}
+      - : A string specifying the behavior when a date component is out of range. Possible values are:
+        - `"constrain"` (default)
+          - : The date component is [clamped](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate#invalid_date_clamping) to the valid range.
+        - `"reject"`
+          - : A {{jsxref("RangeError")}} is thrown if the date component is out of range.
+
+### Return value
+
+A new `Temporal.PlainYearMonth` object representing the year-month specified by the original `PlainYearMonth`, minus the duration.
+
+## Description
+
+Subtracting a duration is equivalent to [adding](Web/JavaScript/Reference/Global_Objects/Temporal/PlainYearMonth/add) its [negation](Web/JavaScript/Reference/Global_Objects/Temporal/Duration/negated), so all the same considerations apply. Subtracting a positive duration starts from the end of the year-month and moves backward, so any increment smaller than the month's length is ignored.
+
+## Examples
+
+### Subtracting a duration
+
+```js
+const start = Temporal.PlainYearMonth.from("2022-01");
+const end = start.subtract({ years: 1, months: 2, weeks: 3, days: 4 });
+console.log(end.toString()); // 2020-11
+```
+
+For more examples, see {{jsxref("Temporal/PlainYearMonth/add", "add()")}}.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainYearMonth")}}
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/PlainYearMonth/add", "Temporal.PlainYearMonth.prototype.add()")}}
+- {{jsxref("Temporal/PlainYearMonth/since", "Temporal.PlainYearMonth.prototype.since()")}}
+- {{jsxref("Temporal/PlainYearMonth/until", "Temporal.PlainYearMonth.prototype.until()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/tojson/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/tojson/index.md
new file mode 100644
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--- /dev/null
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@@ -0,0 +1,70 @@
+---
+title: Temporal.PlainYearMonth.prototype.toJSON()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainYearMonth/toJSON
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainYearMonth.toJSON
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toJSON()`** method of {{jsxref("Temporal.PlainYearMonth")}} instances returns a string representing this year-month in the same [RFC 9557 format](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainYearMonth#rfc_9557_format) as calling {{jsxref("Temporal/PlainYearMonth/toString", "toString()")}}. It is intended to be implicitly called by {{jsxref("JSON.stringify()")}}.
+
+## Syntax
+
+```js-nolint
+toJSON()
+```
+
+### Parameters
+
+None.
+
+### Return value
+
+A string representing the given date in the [RFC 9557 format](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainYearMonth#rfc_9557_format), with the calendar annotation included if it is not `"iso8601"`.
+
+## Description
+
+The `toJSON()` method is automatically called by {{jsxref("JSON.stringify()")}} when a `Temporal.PlainYearMonth` object is stringified. This method is generally intended to, by default, usefully serialize `Temporal.PlainYearMonth` objects during [JSON](/en-US/docs/Glossary/JSON) serialization, which can then be deserialized using the {{jsxref("Temporal/PlainYearMonth/from", "Temporal.PlainYearMonth.from()")}} function as the reviver of {{jsxref("JSON.parse()")}}.
+
+## Examples
+
+### Using toJSON()
+
+```js
+const ym = Temporal.PlainYearMonth.from({ year: 2021, month: 8 });
+const ymStr = ym.toJSON(); // '2021-08'
+const ym2 = Temporal.PlainYearMonth.from(ymStr);
+```
+
+### JSON serialization and parsing
+
+This example shows how `Temporal.PlainYearMonth` can be serialized as JSON without extra effort, and how to parse it back.
+
+```js
+const ym = Temporal.PlainYearMonth.from({ year: 2021, month: 8 });
+const ymStr = JSON.stringify({ event: ym }); // '{"event":"2021-08"}'
+const obj = JSON.parse(ymStr, (key, value) => {
+  if (key === "event") {
+    return Temporal.PlainYearMonth.from(value);
+  }
+  return value;
+});
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainYearMonth")}}
+- {{jsxref("Temporal/PlainYearMonth/from", "Temporal.PlainYearMonth.from()")}}
+- {{jsxref("Temporal/PlainYearMonth/toString", "Temporal.PlainYearMonth.prototype.toString()")}}
+- {{jsxref("Temporal/PlainYearMonth/toLocaleString", "Temporal.PlainYearMonth.prototype.toLocaleString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/tolocalestring/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/tolocalestring/index.md
new file mode 100644
index 000000000000000..2183e83814755da
--- /dev/null
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@@ -0,0 +1,103 @@
+---
+title: Temporal.PlainYearMonth.prototype.toLocaleString()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainYearMonth/toLocaleString
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainYearMonth.toLocaleString
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toLocaleString()`** method of {{jsxref("Temporal.PlainYearMonth")}} instances returns a string with a language-sensitive representation of this year-month. In implementations with [`Intl.DateTimeFormat` API](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat) support, this method delegates to `Intl.DateTimeFormat`.
+
+Every time `toLocaleString` is called, it has to perform a search in a big database of localization strings, which is potentially inefficient. When the method is called many times with the same arguments, it is better to create a {{jsxref("Intl.DateTimeFormat")}} object and use its {{jsxref("Intl/DateTimeFormat/format", "format()")}} method, because a `DateTimeFormat` object remembers the arguments passed to it and may decide to cache a slice of the database, so future `format` calls can search for localization strings within a more constrained context.
+
+## Syntax
+
+```js-nolint
+toLocaleString()
+toLocaleString(locales)
+toLocaleString(locales, options)
+```
+
+### Parameters
+
+The `locales` and `options` parameters customize the behavior of the function and let applications specify the language whose formatting conventions should be used.
+
+In implementations that support the [`Intl.DateTimeFormat` API](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat), these parameters correspond exactly to the [`Intl.DateTimeFormat()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat/DateTimeFormat) constructor's parameters. Implementations without `Intl.DateTimeFormat` support return the exact same string as {{jsxref("Temporal/PlainYearMonth/toString", "toString()")}}, ignoring both parameters.
+
+- `locales` {{optional_inline}}
+  - : A string with a BCP 47 language tag, or an array of such strings. Corresponds to the [`locales`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat/DateTimeFormat#locales) parameter of the `Intl.DateTimeFormat()` constructor.
+- `options` {{optional_inline}}
+
+  - : An object adjusting the output format. Corresponds to the [`options`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat/DateTimeFormat#options) parameter of the `Intl.DateTimeFormat()` constructor. The `calendar` option must be provided with the same value as this year-month's calendar. Regarding the [date-time component options](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat/DateTimeFormat#date-time_component_options) and the style shortcuts (`dateStyle` and `timeStyle`), the options should follow one of these forms:
+
+    - Provide none of them: `year` and `month` will default to `"numeric"`.
+    - Provide `dateStyle` only: it expands to `era`, `year`, and `month` formats.
+    - Provide some date-time component options, where at least one of them is `year` or `month`. Only the specified date components will be included in the output.
+
+See the [`Intl.DateTimeFormat()` constructor](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat/DateTimeFormat) for details on these parameters and how to use them.
+
+### Return value
+
+A string representing the given year-month according to language-specific conventions.
+
+In implementations with `Intl.DateTimeFormat`, this is equivalent to `new Intl.DateTimeFormat(locales, options).format(yearMonth)`, where `options` has been normalized as described above.
+
+> [!NOTE]
+> Most of the time, the formatting returned by `toLocaleString()` is consistent. However, the output may vary between implementations, even within the same locale — output variations are by design and allowed by the specification. It may also not be what you expect. For example, the string may use non-breaking spaces or be surrounded by bidirectional control characters. You should not compare the results of `toLocaleString()` to hardcoded constants.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown if any of the options is invalid.
+- {{jsxref("TypeError")}}
+  - : Thrown if any of the options is not of the expected type.
+
+## Examples
+
+### Using toLocaleString()
+
+Basic use of this method without specifying a `locale` returns a formatted string in the default locale and with default options.
+
+```js
+// Note that just specifying "2021-08" defaults to the ISO 8601 calendar,
+// which throws an error if the locale's default calendar is not ISO 8601.
+const ym = Temporal.PlainYearMonth.from("2021-08-01[u-ca=gregory]");
+
+console.log(ym.toLocaleString()); // 8/2021 (assuming en-US locale and Gregorian calendar)
+```
+
+If the year-month's calendar doesn't match the locale's default calendar, even when its calendar is `iso8601`, an explicit `calendar` option must be provided with the same value.
+
+```js
+const ym = Temporal.PlainYearMonth.from("2021-08");
+ym.toLocaleString("en-US", { calendar: "iso8601" }); // 2021-08
+```
+
+### Using toLocaleString() with options
+
+You can customize which parts of the year-month are included in the output by providing the `options` parameter.
+
+```js
+const ym = Temporal.PlainYearMonth.from("2021-08-01[u-ca=gregory]");
+ym.toLocaleString("en-US", { dateStyle: "full" }); // August 2021
+ym.toLocaleString("en-US", { year: "2-digit" }); // 21
+ym.toLocaleString("en-US", { month: "long" }); // August
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainYearMonth")}}
+- {{jsxref("Intl.DateTimeFormat")}}
+- {{jsxref("Temporal/PlainYearMonth/toJSON", "Temporal.PlainYearMonth.prototype.toJSON()")}}
+- {{jsxref("Temporal/PlainYearMonth/toString", "Temporal.PlainYearMonth.prototype.toString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/toplaindate/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/toplaindate/index.md
new file mode 100644
index 000000000000000..c6ddef349b5eae7
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/toplaindate/index.md
@@ -0,0 +1,64 @@
+---
+title: Temporal.PlainYearMonth.prototype.toPlainDate()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainYearMonth/toPlainDate
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainYearMonth.toPlainDate
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toPlainDate()`** method of {{jsxref("Temporal.PlainYearMonth")}} instances returns a new {{jsxref("Temporal.PlainDate")}} object representing this year-month and a supplied day in the same calendar system.
+
+## Syntax
+
+```js-nolint
+toPlainDate(dayInfo)
+```
+
+### Parameters
+
+- `dayInfo` {{optional_inline}}
+  - : An object representing the day component of the resulting `PlainDate`, containing the following property:
+    - `day`
+      - : Corresponds to the {{jsxref("Temporal/PlainDate/day", "day")}} property.
+
+### Return value
+
+A new `Temporal.PlainDate` object representing the date specified by this year-month and the day in `dayInfo`, interpreted in the calendar system of this year-month.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown if any of the options is invalid.
+- {{jsxref("TypeError")}}
+  - : Thrown if `dayInfo` is not an object.
+
+## Examples
+
+### Using toPlainDate()
+
+```js
+const ym = Temporal.PlainYearMonth.from("2021-07");
+const date = ym.toPlainDate({ day: 1 });
+console.log(date.toString()); // 2021-07-01
+
+const ym2 = Temporal.PlainYearMonth.from("2021-07-01[u-ca=chinese]");
+const date2 = ym2.toPlainDate({ day: 15 });
+console.log(date2.toString()); // 2021-06-24[u-ca=chinese]
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainYearMonth")}}
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal/PlainDate/toPlainYearMonth", "Temporal.PlainDate.prototype.toPlainYearMonth()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/tostring/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/tostring/index.md
new file mode 100644
index 000000000000000..3a08af1ae684db1
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/tostring/index.md
@@ -0,0 +1,95 @@
+---
+title: Temporal.PlainYearMonth.prototype.toString()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainYearMonth/toString
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainYearMonth.toString
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toString()`** method of {{jsxref("Temporal.PlainYearMonth")}} instances returns a string representing this year-month in the [RFC 9557 format](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainYearMonth#rfc_9557_format).
+
+## Syntax
+
+```js-nolint
+toString()
+toString(options)
+```
+
+### Parameters
+
+- `options` {{optional_inline}}
+  - : An object containing the following property:
+    - `calendarName` {{optional_inline}}
+      - : Whether to show the calendar annotation (`[u-ca=calendar_id]`) in the return value. Possible values are:
+        - `"auto"` (default)
+          - : Include the calendar annotation if the calendar is not `"iso8601"`. The reference day is included if the calendar is not `"iso8601"`.
+        - `"always"`
+          - : Always include the calendar annotation. The reference day is always included too.
+        - `"never"`
+          - : Never include the calendar annotation. This makes the returned string not recoverable to the same {{jsxref("Temporal.PlainYearMonth")}} instance, although the year-month value still remains the same. The reference day is included if the calendar is not `"iso8601"`.
+        - `"critical"`
+          - : Always include the calendar annotation, and add a critical flag: `[!u-ca=calendar_id]`. Useful when sending the string to certain systems, but not useful for Temporal itself. The reference day is always included too.
+
+### Return value
+
+A string in the [RFC 9557 format](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainYearMonth#rfc_9557_format) representing this year-month. The calendar annotation is included as specified. The reference day is included if a calendar annotation is included or if the calendar is not `"iso8601"`.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown if any of the options is invalid.
+- {{jsxref("TypeError")}}
+  - : Thrown if `options` is not an object or `undefined`.
+
+## Examples
+
+### Using toString()
+
+```js
+const ym = Temporal.PlainYearMonth.from({ year: 2021, month: 8 });
+console.log(ym.toString()); // '2021-08'
+
+const ym2 = Temporal.PlainYearMonth.from({
+  year: 4658,
+  monthCode: "M08",
+  calendar: "chinese",
+});
+console.log(ym2.toString()); // '2021-09-07[u-ca=chinese]'
+```
+
+### Using options
+
+```js
+const isoYM = Temporal.PlainYearMonth.from({ year: 2021, month: 8 });
+const ym = Temporal.PlainYearMonth.from({
+  year: 4658,
+  monthCode: "M08",
+  calendar: "chinese",
+});
+console.log(isoYM.toString({ calendarName: "auto" })); // '2021-08'
+console.log(ym.toString({ calendarName: "auto" })); // '2021-09-07[u-ca=chinese]'
+console.log(isoYM.toString({ calendarName: "always" })); // '2021-08-01[u-ca=iso8601]'
+console.log(ym.toString({ calendarName: "always" })); // '2021-09-07[u-ca=chinese]'
+console.log(isoYM.toString({ calendarName: "never" })); // '2021-08'
+console.log(ym.toString({ calendarName: "never" })); // '2021-09-07'
+console.log(isoYM.toString({ calendarName: "critical" })); // '2021-08-01[!u-ca=iso8601]'
+console.log(ym.toString({ calendarName: "critical" })); // '2021-09-07[!u-ca=chinese]'
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainYearMonth")}}
+- {{jsxref("Temporal/PlainYearMonth/from", "Temporal.PlainYearMonth.from()")}}
+- {{jsxref("Temporal/PlainYearMonth/toJSON", "Temporal.PlainYearMonth.prototype.toJSON()")}}
+- {{jsxref("Temporal/PlainYearMonth/toLocaleString", "Temporal.PlainYearMonth.prototype.toLocaleString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/until/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/until/index.md
new file mode 100644
index 000000000000000..3530eb93a893280
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/until/index.md
@@ -0,0 +1,68 @@
+---
+title: Temporal.PlainYearMonth.prototype.until()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainYearMonth/until
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainYearMonth.until
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`until()`** method of {{jsxref("Temporal.PlainYearMonth")}} instances returns a new {{jsxref("Temporal.Duration")}} object representing the duration from this year-month to another year-month (in a form convertible by {{jsxref("Temporal/PlainYearMonth/from", "Temporal.PlainYearMonth.from()")}}). The duration is positive if the other month is after this month, and negative if before.
+
+This method does `other - this`. To do `this - other`, use the {{jsxref("Temporal/PlainYearMonth/since", "since()")}} method.
+
+## Syntax
+
+```js-nolint
+until(other)
+until(other, options)
+```
+
+### Parameters
+
+- `other`
+  - : A string, an object, or a {{jsxref("Temporal.PlainYearMonth")}} instance representing a year-month to subtract this year-month from. It is converted to a `Temporal.PlainYearMonth` object using the same algorithm as {{jsxref("Temporal/PlainYearMonth/from", "Temporal.PlainYearMonth.from()")}}. It must have the same calendar as `this`.
+- `options` {{optional_inline}}
+  - : The same options as [`since()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainYearMonth/since#options).
+
+### Return value
+
+A new {{jsxref("Temporal.Duration")}} object representing the duration from this year-month _until_ `other`. The duration is positive if `other` is after this year-month, and negative if before.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown in one of the following cases:
+    - `other` has a different calendar than `this`.
+    - Any of the options is invalid.
+
+## Examples
+
+### Using until()
+
+```js
+const launch = Temporal.PlainYearMonth.from("2035-01");
+const now = Temporal.Now.plainDateISO().toPlainYearMonth();
+const duration = now.until(launch);
+console.log(`It will be ${duration.toLocaleString("en-US")} until the launch`);
+```
+
+For more examples, see [`since()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainYearMonth/since).
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainYearMonth")}}
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/PlainYearMonth/add", "Temporal.PlainYearMonth.prototype.add()")}}
+- {{jsxref("Temporal/PlainYearMonth/subtract", "Temporal.PlainYearMonth.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainYearMonth/since", "Temporal.PlainYearMonth.prototype.since()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/valueof/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/valueof/index.md
new file mode 100644
index 000000000000000..ab1fa90ed857310
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/valueof/index.md
@@ -0,0 +1,66 @@
+---
+title: Temporal.PlainYearMonth.prototype.valueOf()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainYearMonth/valueOf
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainYearMonth.valueOf
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`valueOf()`** method of {{jsxref("Temporal.PlainYearMonth")}} instances throws a {{jsxref("TypeError")}}, which prevents `Temporal.PlainYearMonth` instances from being [implicitly converted to primitives](/en-US/docs/Web/JavaScript/Data_structures#primitive_coercion) when used in arithmetic or comparison operations.
+
+## Syntax
+
+```js-nolint
+valueOf()
+```
+
+### Parameters
+
+None.
+
+### Return value
+
+None.
+
+### Exceptions
+
+- {{jsxref("TypeError")}}
+  - : Always thrown.
+
+## Description
+
+Because both [primitive conversion](/en-US/docs/Web/JavaScript/Data_structures#primitive_coercion) and [number conversion](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number#number_coercion) call `valueOf()` before `toString()`, if `valueOf()` is absent, then an expression like `yearMonth1 > yearMonth2` would implicitly compare them as strings, which may have unexpected results. By throwing a `TypeError`, `Temporal.PlainYearMonth` instances prevent such implicit conversions. You need to explicitly convert them to strings using {{jsxref("Temporal/PlainYearMonth/toString", "Temporal.PlainYearMonth.prototype.toString()")}}, or use the {{jsxref("Temporal/PlainYearMonth/compare", "Temporal.PlainYearMonth.compare()")}} static method to compare them.
+
+## Examples
+
+### Arithmetic and comparison operations on Temporal.PlainYearMonth
+
+All arithmetic and comparison operations on `Temporal.PlainYearMonth` instances should use the dedicated methods or convert them to primitives explicitly.
+
+```js
+const ym1 = Temporal.PlainYearMonth.from("2021-01");
+const ym2 = Temporal.PlainYearMonth.from("2021-07");
+ym1 > ym2; // TypeError: can't convert PlainYearMonth to primitive type
+Temporal.PlainYearMonth.compare(ym1, ym2); // -1
+
+ym2 - ym1; // TypeError: can't convert PlainYearMonth to primitive type
+ym2.since(ym1).toString(); // "P6M"
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainYearMonth")}}
+- {{jsxref("Temporal/PlainYearMonth/toString", "Temporal.PlainYearMonth.prototype.toString()")}}
+- {{jsxref("Temporal/PlainYearMonth/toJSON", "Temporal.PlainYearMonth.prototype.toJSON()")}}
+- {{jsxref("Temporal/PlainYearMonth/toLocaleString", "Temporal.PlainYearMonth.prototype.toLocaleString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/with/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/with/index.md
new file mode 100644
index 000000000000000..3a1f62bc2173086
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/with/index.md
@@ -0,0 +1,75 @@
+---
+title: Temporal.PlainYearMonth.prototype.with()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainYearMonth/with
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainYearMonth.with
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`with()`** method of {{jsxref("Temporal.PlainYearMonth")}} instances returns a new `Temporal.PlainYearMonth` object representing this year-month with some fields replaced by new values. Because all `Temporal` objects are designed to be immutable, this method essentially functions as the setter for the year-month's fields.
+
+There's no obvious way to create a new `Temporal.PlainYearMonth` object that represents the same year-month in a different calendar, so to replace its `calendarId` property, you need to convert it to a {{jsxref("Temporal.PlainDate")}} object first using {{jsxref("Temporal/PlainYearMonth/toPlainDate", "toPlainDate()")}}, change the calendar, and then convert it back.
+
+## Syntax
+
+```js-nolint
+with(info)
+with(info, options)
+```
+
+### Parameters
+
+- `info`
+  - : An object containing at least one of the properties recognized by {{jsxref("Temporal/PlainYearMonth/from", "Temporal.PlainYearMonth.from()")}} (except `calendar`): `era` and `eraYear`, `month`, `monthCode`, `year`. Unspecified properties use the values from the original year-month. You only need to provide one of `month` or `monthCode`, and one of `era` and `eraYear` or `year`, and the other will be updated accordingly.
+- `options` {{optional_inline}}
+  - : An object containing the following property:
+    - `overflow` {{optional_inline}}
+      - : A string specifying the behavior when a date component is out of range. Possible values are:
+        - `"constrain"` (default)
+          - : The date component is [clamped](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate#invalid_date_clamping) to the valid range.
+        - `"reject"`
+          - : A {{jsxref("RangeError")}} is thrown if the date component is out of range.
+
+### Return value
+
+A new `Temporal.PlainYearMonth` object, where the fields specified in `info` that are not `undefined` are replaced by the corresponding values, and the rest of the fields are copied from the original date.
+
+### Exceptions
+
+- {{jsxref("TypeError")}}
+  - : Thrown in one of the following cases:
+    - `info` is not an object.
+    - `options` is not an object or `undefined`.
+- {{jsxref("RangeError")}}
+  - : Thrown in one of the following cases:
+    - The provided properties that specify the same component are inconsistent.
+    - The provided non-numerical properties are not valid; for example, if `monthCode` is never a valid month code in this calendar.
+    - The provided numerical properties are out of range, and `options.overflow` is set to `"reject"`.
+
+## Examples
+
+### Using with()
+
+```js
+const ym = Temporal.PlainYearMonth.from("2021-07");
+const newYM = ym.with({ year: 2024 });
+console.log(newYM.toString()); // "2024-07"
+```
+
+For more examples, see the documentation for the individual properties that can be set using `with()`.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainYearMonth")}}
+- {{jsxref("Temporal/PlainYearMonth/from", "Temporal.PlainYearMonth.from()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/year/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/year/index.md
new file mode 100644
index 000000000000000..56c7641c928e654
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/plainyearmonth/year/index.md
@@ -0,0 +1,44 @@
+---
+title: Temporal.PlainYearMonth.prototype.year
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/PlainYearMonth/year
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.PlainYearMonth.year
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`year`** accessor property of {{jsxref("Temporal.PlainYearMonth")}} instances returns an integer representing the number of years of this year-month relative to the start of a calendar-specific epoch year. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+The set accessor of `year` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/PlainYearMonth/with", "with()")}} method to create a new `Temporal.PlainYearMonth` object with the desired new value.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/year", "Temporal.PlainDate.prototype.year")}}.
+
+## Examples
+
+### Using year
+
+```js
+const ym = Temporal.PlainYearMonth.from("2021-07"); // ISO 8601 calendar
+console.log(ym.year); // 2021
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.PlainYearMonth")}}
+- {{jsxref("Temporal/PlainYearMonth/with", "Temporal.PlainYearMonth.prototype.with()")}}
+- {{jsxref("Temporal/PlainYearMonth/add", "Temporal.PlainYearMonth.prototype.add()")}}
+- {{jsxref("Temporal/PlainYearMonth/subtract", "Temporal.PlainYearMonth.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainYearMonth/era", "Temporal.PlainYearMonth.prototype.era")}}
+- {{jsxref("Temporal/PlainYearMonth/eraYear", "Temporal.PlainYearMonth.prototype.eraYear")}}
+- {{jsxref("Temporal/PlainYearMonth/month", "Temporal.PlainYearMonth.prototype.month")}}
+- {{jsxref("Temporal/PlainDate/year", "Temporal.PlainDate.prototype.year")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/add/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/add/index.md
new file mode 100644
index 000000000000000..6a2b20c9d76ef4d
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/add/index.md
@@ -0,0 +1,93 @@
+---
+title: Temporal.ZonedDateTime.prototype.add()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/add
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.add
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`add()`** method of {{jsxref("Temporal.ZonedDateTime")}} instances returns a new `Temporal.ZonedDateTime` object representing this date-time moved forward by a given duration (in a form convertible by {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}).
+
+## Syntax
+
+```js-nolint
+add(duration)
+add(duration, options)
+```
+
+### Parameters
+
+- `duration`
+  - : A string, an object, or a {{jsxref("Temporal.Duration")}} instance representing a duration to add to this date-time. It is converted to a `Temporal.Duration` object using the same algorithm as {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}.
+- `options` {{optional_inline}}
+  - : An object containing the following property:
+    - `overflow` {{optional_inline}}
+      - : A string specifying the behavior when a date component is out of range. Possible values are:
+        - `"constrain"` (default)
+          - : The date component is [clamped](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate#invalid_date_clamping) to the valid range.
+        - `"reject"`
+          - : A {{jsxref("RangeError")}} is thrown if the date component is out of range.
+
+### Return value
+
+A new `Temporal.ZonedDateTime` object representing the date-time specified by the original `ZonedDateTime`, plus the duration.
+
+## Description
+
+For how [calendar durations](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#calendar_durations) are added, see {{jsxref("Temporal/PlainDate/add", "Temporal.PlainDate.prototype.add()")}}.
+
+Addition and subtraction are performed according to rules defined in [RFC 5545 (iCalendar)](https://datatracker.ietf.org/doc/html/rfc5545):
+
+- Add/subtract the date portion of a duration using calendar arithmetic; in other words, add the date portion to its `PlainDateTime` using {{jsxref("Temporal/PlainDateTime/add", "Temporal.PlainDateTime.prototype.add()")}}, and then interpret the result in the same time zone. The result will automatically adjust for daylight saving time using the rules of this instance's `timeZone` field. For example, `2024-11-03T01:00:00-04:00[America/New_York]` plus one day is `2024-11-04T01:00:00-05:00[America/New_York]`, as if the day has 25 hours.
+  - If the date-time is [ambiguous](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#ambiguity_and_gaps_from_local_time_to_utc_time) or invalid due to a time zone offset transition, it is resolved using the `disambiguation: "compatible"` behavior: the later of the two possible instants will be used for time-skipped transitions and the earlier of the two possible instants will be used for time-repeated transitions. For example, `2024-03-09T02:05:00-05:00[America/New_York]` plus one day is supposedly `2024-03-10T02:05:00-05:00[America/New_York]`, but this time doesn't exist, so the wall-clock time one hour after, `2024-03-10T03:05:00-04:00[America/New_York]`, is returned.
+  - If the [offset is ambiguous](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#offset_ambiguity), it is resolved using the `offset: "prefer"` behavior: the offset is used if it's valid for the time zone and the local time, and recalculated otherwise. For example, `2024-11-02T01:00:00-04:00[America/New_York]` plus one day is `2024-11-03T01:00:00-04:00[America/New_York]`, while `2024-11-04T01:00:00-05:00[America/New_York]` minus one day is `2024-11-03T01:00:00-05:00[America/New_York]`.
+  - If the resulting date-time's components are out of bounds, they are resolved using the `overflow` option. For example, `2024-08-31` plus one month is `2024-09-31` which doesn't exist, so it is clamped to `2024-09-30` by default.
+- Add/subtract the time portion of a duration using real-world time; in other words, add the time portion to its `Instant` using {{jsxref("Temporal/Instant/add", "Temporal.Instant.prototype.add()")}}, and then interpret the result in the same time zone. For example, `2024-11-03T01:00:00-04:00[America/New_York]` plus one hour is `2024-11-03T01:00:00-05:00[America/New_York]`.
+
+These rules make arithmetic with `Temporal.ZonedDateTime` "DST-safe", which means that the results most closely match the expectations of both real-world users and implementers of other standards-compliant calendar applications. These expectations include:
+
+- Adding or subtracting days should keep clock time consistent across DST transitions. For example, if you have an appointment on Saturday at 1:00PM and you ask to reschedule it 1 day later, you would expect the reschedule appointment to still be at 1:00PM, even if there was a DST transition overnight.
+- Adding or subtracting the time portion of a duration should ignore DST transitions. For example, a friend you've asked to meet in in 2 hours will be annoyed if you show up 1 hour or 3 hours later. There should be a consistent and relatively-unsurprising order of operations.
+- If results are at or near a DST transition, ambiguities should be handled automatically (no crashing) and deterministically.
+
+Adding a duration is equivalent to [subtracting](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/subtract) its [negation](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration/negated).
+
+## Examples
+
+### Adding a duration
+
+```js
+const start = Temporal.ZonedDateTime.from(
+  "2021-11-01T12:34:56-04:00[America/New_York]",
+);
+const end = start.add({
+  years: 1,
+  months: 2,
+  weeks: 3,
+  days: 4,
+  hours: 5,
+  minutes: 6,
+  seconds: 7,
+  milliseconds: 8,
+});
+console.log(end.toString()); // 2023-01-26T17:41:03.008-05:00[America/New_York]
+```
+
+For more examples, especially with how different calendars and the `overflow` option interact with calendar durations, see {{jsxref("Temporal/PlainDate/add", "Temporal.PlainDate.prototype.add()")}}.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/ZonedDateTime/subtract", "Temporal.ZonedDateTime.prototype.subtract()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/calendarid/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/calendarid/index.md
new file mode 100644
index 000000000000000..82aa16426769fb5
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/calendarid/index.md
@@ -0,0 +1,47 @@
+---
+title: Temporal.ZonedDateTime.prototype.calendarId
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/calendarId
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.calendarId
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`calendarId`** accessor property of {{jsxref("Temporal.ZonedDateTime")}} instances returns a string representing the [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars) used to interpret the internal ISO 8601 date.
+
+For a list of commonly supported values, see {{jsxref("Intl/Locale/getCalendars", "Intl.Locale.prototype.getCalendars()")}}.
+
+The set accessor of `calendarId` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/ZonedDateTime/withCalendar", "withCalendar()")}} method to create a new `Temporal.ZonedDateTime` object with the desired new value.
+
+## Examples
+
+### Using calendarId
+
+```js
+const dt = Temporal.ZonedDateTime.from(
+  "2021-07-01T08:00:00-04:00[America/New_York]",
+);
+console.log(dt.calendarId); // "iso8601"; default
+
+const dt2 = Temporal.ZonedDateTime.from(
+  "2021-07-01T08:00:00+08:00[Asia/Shanghai][u-ca=chinese]",
+);
+console.log(dt2.calendarId); // "chinese"
+
+const dt3 = dt2.withCalendar("hebrew");
+console.log(dt3.calendarId); // "hebrew"
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/compare/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/compare/index.md
new file mode 100644
index 000000000000000..b287845fc0d8a62
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/compare/index.md
@@ -0,0 +1,87 @@
+---
+title: Temporal.ZonedDateTime.compare()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/compare
+page-type: javascript-static-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.compare
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.ZonedDateTime.compare()`** static method returns a number (-1, 0, or 1) indicating whether the first date-time comes before, is the same as, or comes after the second date-time. It is equivalent to comparing the {{jsxref("Temporal/ZonedDateTime/epochNanoseconds", "epochNanoseconds")}} of the two datetimes.
+
+## Syntax
+
+```js-nolint
+Temporal.ZonedDateTime.compare(dateTime1, dateTime2)
+```
+
+### Parameters
+
+- `dateTime1`
+  - : A string, an object, or a {{jsxref("Temporal.ZonedDateTime")}} instance representing the first date-time to compare. It is converted to a `Temporal.ZonedDateTime` object using the same algorithm as {{jsxref("Temporal/ZonedDateTime/from", "Temporal.ZonedDateTime.from()")}}.
+- `dateTime2`
+  - : The second date-time to compare, converted to a `Temporal.ZonedDateTime` object using the same algorithm as `dateTime1`.
+
+### Return value
+
+Returns `-1` if `dateTime1` comes before `dateTime2`, `0` if they are the same, and `1` if `dateTime2` comes after. They are compared by their underlying instant values, ignoring their calendars or time zones.
+
+## Examples
+
+### Using Temporal.ZonedDateTime.compare()
+
+```js
+const dt1 = Temporal.ZonedDateTime.from("2021-08-01T01:00:00[Europe/London]");
+const dt2 = Temporal.ZonedDateTime.from("2021-08-02T00:00:00[Europe/London]");
+console.log(Temporal.ZonedDateTime.compare(dt1, dt2)); // -1
+
+const dt3 = Temporal.ZonedDateTime.from("2021-08-01T00:00:00[Europe/London]");
+console.log(Temporal.ZonedDateTime.compare(dt1, dt3)); // 1
+```
+
+### Sorting an array of date-times
+
+The purpose of this `compare()` function is to act as a comparator to be passed to {{jsxref("Array.prototype.sort()")}} and related functions.
+
+```js
+const dateTimes = [
+  Temporal.ZonedDateTime.from("2021-08-01T00:00:00[America/New_York]"),
+  Temporal.ZonedDateTime.from("2021-08-01T00:00:00[Asia/Hong_Kong]"),
+  Temporal.ZonedDateTime.from("2021-08-01T00:00:00[Europe/London]"),
+];
+
+dateTimes.sort(Temporal.ZonedDateTime.compare);
+console.log(dateTimes.map((d) => d.toString()));
+// [ "2021-08-01T00:00:00+08:00[Asia/Hong_Kong]", "2021-08-01T00:00:00+01:00[Europe/London]", "2021-08-01T00:00:00-04:00[America/New_York]" ]
+```
+
+Note that they are compared by their instant values. In the very rare case where you want to compare them by their wall-clock times, convert them to `PlainDateTime` first.
+
+```js
+const dateTimes = [
+  Temporal.ZonedDateTime.from("2021-08-01T00:00:00[America/New_York]"),
+  Temporal.ZonedDateTime.from("2021-08-01T00:00:00[Asia/Hong_Kong]"),
+  Temporal.ZonedDateTime.from("2021-08-01T00:00:00[Europe/London]"),
+];
+
+dateTimes.sort((a, b) =>
+  Temporal.PlainDateTime.compare(a.toPlainDateTime(), b.toPlainDateTime()),
+);
+console.log(dateTimes.map((d) => d.toString()));
+// [ "2021-08-01T00:00:00-04:00[America/New_York]", "2021-08-01T00:00:00+08:00[Asia/Hong_Kong]", "2021-08-01T00:00:00+01:00[Europe/London]" ]
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/equals", "Temporal.ZonedDateTime.prototype.equals()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/day/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/day/index.md
new file mode 100644
index 000000000000000..b6b14944a7d76f4
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/day/index.md
@@ -0,0 +1,63 @@
+---
+title: Temporal.ZonedDateTime.prototype.day
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/day
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.day
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`day`** accessor property of {{jsxref("Temporal.ZonedDateTime")}} instances returns a positive integer representing the 1-based day index in the month of this date, which is the same day number you would see on a calendar. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+The set accessor of `day` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/ZonedDateTime/with", "with()")}} method to create a new `Temporal.ZonedDateTime` object with the desired new value.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/day", "Temporal.PlainDate.prototype.day")}}.
+
+For `PlainDate`, `day` can only be non-continuous if the calendar skips days. For `ZonedDateTime`, `day` can also be non-continuous if the time zone changes its offset by 24 hours; this actually happened. See the example below.
+
+## Examples
+
+### Using day
+
+```js
+const dt = Temporal.ZonedDateTime.from("2021-07-01[America/New_York]"); // ISO 8601 calendar
+console.log(dt.day); // 1
+```
+
+### Non-continuous day
+
+To better align times with its trading partners in Asia, the country of Samoa [changed its time zone](https://en.wikipedia.org/wiki/Time_in_Samoa) to the other side of the International Date Line, shifting its offset from -10:00 to +14:00 (daylight saving time). This resulted in a 24-hour abrupt change in the local time, therefore skipping the day December 30, 2011 entirely. `2011-12-29T23:59:59-10:00[Pacific/Apia]` is immediately followed by `2011-12-31T00:00:00+14:00[Pacific/Apia]`.
+
+```js
+const dt = Temporal.ZonedDateTime.from(
+  "2011-12-29T23:59:59-10:00[Pacific/Apia]",
+);
+console.log(dt.day); // 29
+const nextDay = dt.add({ seconds: 1 });
+console.log(nextDay.day); // 31
+```
+
+For this reason, you should always prefer {{jsxref("Temporal/ZonedDateTime/add", "add()")}} and {{jsxref("Temporal/ZonedDateTime/subtract", "subtract()")}} to manipulate dates and times, rather than directly changing the `day` property.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/with", "Temporal.ZonedDateTime.prototype.with()")}}
+- {{jsxref("Temporal/ZonedDateTime/add", "Temporal.ZonedDateTime.prototype.add()")}}
+- {{jsxref("Temporal/ZonedDateTime/subtract", "Temporal.ZonedDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/ZonedDateTime/year", "Temporal.ZonedDateTime.prototype.year")}}
+- {{jsxref("Temporal/ZonedDateTime/month", "Temporal.ZonedDateTime.prototype.month")}}
+- {{jsxref("Temporal/ZonedDateTime/daysInMonth", "Temporal.ZonedDateTime.prototype.daysInMonth")}}
+- {{jsxref("Temporal/ZonedDateTime/dayOfWeek", "Temporal.ZonedDateTime.prototype.dayOfWeek")}}
+- {{jsxref("Temporal/ZonedDateTime/dayOfYear", "Temporal.ZonedDateTime.prototype.dayOfYear")}}
+- {{jsxref("Temporal/PlainDate/day", "Temporal.PlainDate.prototype.day")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/dayofweek/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/dayofweek/index.md
new file mode 100644
index 000000000000000..4deea2f59108e5b
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/dayofweek/index.md
@@ -0,0 +1,46 @@
+---
+title: Temporal.ZonedDateTime.prototype.dayOfWeek
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/dayOfWeek
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.dayOfWeek
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`dayOfWeek`** accessor property of {{jsxref("Temporal.ZonedDateTime")}} instances returns a positive integer representing the 1-based day index in the week of this date. Days in a week are numbered sequentially from `1` to {{jsxref("Temporal/ZonedDateTime/daysInWeek", "daysInWeek")}}, with each number mapping to its name. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+The set accessor of `dayOfWeek` is `undefined`. You cannot change this property directly. To create a new `Temporal.ZonedDateTime` object with the desired new `dayOfWeek` value, use the {{jsxref("Temporal/ZonedDateTime/add", "add()")}} or {{jsxref("Temporal/ZonedDateTime/subtract", "subtract()")}} method with the appropriate number of `days`.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/dayOfWeek", "Temporal.PlainDate.prototype.dayOfWeek")}}.
+
+## Examples
+
+### Using dayOfWeek
+
+```js
+const dt = Temporal.ZonedDateTime.from("2021-07-01[America/New_York]");
+console.log(dt.dayOfWeek); // 4; Thursday
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/with", "Temporal.ZonedDateTime.prototype.with()")}}
+- {{jsxref("Temporal/ZonedDateTime/add", "Temporal.ZonedDateTime.prototype.add()")}}
+- {{jsxref("Temporal/ZonedDateTime/subtract", "Temporal.ZonedDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/ZonedDateTime/day", "Temporal.ZonedDateTime.prototype.day")}}
+- {{jsxref("Temporal/ZonedDateTime/dayOfYear", "Temporal.ZonedDateTime.prototype.dayOfYear")}}
+- {{jsxref("Temporal/ZonedDateTime/daysInWeek", "Temporal.ZonedDateTime.prototype.daysInWeek")}}
+- {{jsxref("Temporal/ZonedDateTime/weekOfYear", "Temporal.ZonedDateTime.prototype.weekOfYear")}}
+- {{jsxref("Temporal/ZonedDateTime/yearOfWeek", "Temporal.ZonedDateTime.prototype.yearOfWeek")}}
+- {{jsxref("Temporal/PlainDate/dayOfWeek", "Temporal.PlainDate.prototype.dayOfWeek")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/dayofyear/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/dayofyear/index.md
new file mode 100644
index 000000000000000..4d67b7ad9ef6b35
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/dayofyear/index.md
@@ -0,0 +1,45 @@
+---
+title: Temporal.ZonedDateTime.prototype.dayOfYear
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/dayOfYear
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.dayOfYear
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`dayOfYear`** accessor property of {{jsxref("Temporal.ZonedDateTime")}} instances returns a positive integer representing the 1-based day index in the year of this date. The first day of this year is `1`, and the last day is the {{jsxref("Temporal/ZonedDateTime/daysInYear", "daysInYear")}}. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+The set accessor of `dayOfYear` is `undefined`. You cannot change this property directly. To create a new `Temporal.ZonedDateTime` object with the desired new `dayOfYear` value, use the {{jsxref("Temporal/ZonedDateTime/add", "add()")}} or {{jsxref("Temporal/ZonedDateTime/subtract", "subtract()")}} method with the appropriate number of `days`.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/dayOfYear", "Temporal.PlainDate.prototype.dayOfYear")}}.
+
+## Examples
+
+### Using dayOfYear
+
+```js
+const dt = Temporal.ZonedDateTime.from("2021-07-01[America/New_York]");
+console.log(dt.dayOfYear); // 182
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/with", "Temporal.ZonedDateTime.prototype.with()")}}
+- {{jsxref("Temporal/ZonedDateTime/add", "Temporal.ZonedDateTime.prototype.add()")}}
+- {{jsxref("Temporal/ZonedDateTime/subtract", "Temporal.ZonedDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/ZonedDateTime/year", "Temporal.ZonedDateTime.prototype.year")}}
+- {{jsxref("Temporal/ZonedDateTime/day", "Temporal.ZonedDateTime.prototype.day")}}
+- {{jsxref("Temporal/ZonedDateTime/dayOfWeek", "Temporal.ZonedDateTime.prototype.dayOfWeek")}}
+- {{jsxref("Temporal/ZonedDateTime/daysInYear", "Temporal.ZonedDateTime.prototype.daysInYear")}}
+- {{jsxref("Temporal/PlainDate/dayOfYear", "Temporal.PlainDate.prototype.dayOfYear")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/daysinmonth/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/daysinmonth/index.md
new file mode 100644
index 000000000000000..02823ef5f2df75b
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/daysinmonth/index.md
@@ -0,0 +1,46 @@
+---
+title: Temporal.ZonedDateTime.prototype.daysInMonth
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/daysInMonth
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.daysInMonth
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`daysInMonth`** accessor property of {{jsxref("Temporal.ZonedDateTime")}} instances returns a positive integer representing the number of days in the month of this date. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+The set accessor of `daysInMonth` is `undefined`. You cannot change this property directly.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/daysInMonth", "Temporal.PlainDate.prototype.daysInMonth")}}.
+
+## Examples
+
+### Using daysInMonth
+
+```js
+const dt = Temporal.ZonedDateTime.from("2021-07-01[America/New_York]");
+console.log(dt.daysInMonth); // 31
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/with", "Temporal.ZonedDateTime.prototype.with()")}}
+- {{jsxref("Temporal/ZonedDateTime/add", "Temporal.ZonedDateTime.prototype.add()")}}
+- {{jsxref("Temporal/ZonedDateTime/subtract", "Temporal.ZonedDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/ZonedDateTime/year", "Temporal.ZonedDateTime.prototype.year")}}
+- {{jsxref("Temporal/ZonedDateTime/month", "Temporal.ZonedDateTime.prototype.month")}}
+- {{jsxref("Temporal/ZonedDateTime/day", "Temporal.ZonedDateTime.prototype.day")}}
+- {{jsxref("Temporal/ZonedDateTime/daysInWeek", "Temporal.ZonedDateTime.prototype.daysInWeek")}}
+- {{jsxref("Temporal/ZonedDateTime/daysInYear", "Temporal.ZonedDateTime.prototype.daysInYear")}}
+- {{jsxref("Temporal/PlainDate/daysInMonth", "Temporal.PlainDate.prototype.daysInMonth")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/daysinweek/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/daysinweek/index.md
new file mode 100644
index 000000000000000..35ccceddd8c0343
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/daysinweek/index.md
@@ -0,0 +1,46 @@
+---
+title: Temporal.ZonedDateTime.prototype.daysInWeek
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/daysInWeek
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.daysInWeek
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`daysInWeek`** accessor property of {{jsxref("Temporal.ZonedDateTime")}} instances returns a positive integer representing the number of days in the week of this date. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+The set accessor of `daysInWeek` is `undefined`. You cannot change this property directly.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/daysInWeek", "Temporal.PlainDate.prototype.daysInWeek")}}.
+
+## Examples
+
+### Using daysInWeek
+
+```js
+const dt = Temporal.ZonedDateTime.from("2021-07-01[America/New_York]");
+console.log(dt.daysInWeek); // 7
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/with", "Temporal.ZonedDateTime.prototype.with()")}}
+- {{jsxref("Temporal/ZonedDateTime/add", "Temporal.ZonedDateTime.prototype.add()")}}
+- {{jsxref("Temporal/ZonedDateTime/subtract", "Temporal.ZonedDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/ZonedDateTime/yearOfWeek", "Temporal.ZonedDateTime.prototype.yearOfWeek")}}
+- {{jsxref("Temporal/ZonedDateTime/weekOfYear", "Temporal.ZonedDateTime.prototype.weekOfYear")}}
+- {{jsxref("Temporal/ZonedDateTime/dayOfWeek", "Temporal.ZonedDateTime.prototype.dayOfWeek")}}
+- {{jsxref("Temporal/ZonedDateTime/daysInMonth", "Temporal.ZonedDateTime.prototype.daysInMonth")}}
+- {{jsxref("Temporal/ZonedDateTime/daysInYear", "Temporal.ZonedDateTime.prototype.daysInYear")}}
+- {{jsxref("Temporal/PlainDate/daysInWeek", "Temporal.PlainDate.prototype.daysInWeek")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/daysinyear/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/daysinyear/index.md
new file mode 100644
index 000000000000000..5d50dc9e718c459
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/daysinyear/index.md
@@ -0,0 +1,45 @@
+---
+title: Temporal.ZonedDateTime.prototype.daysInYear
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/daysInYear
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.daysInYear
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`daysInYear`** accessor property of {{jsxref("Temporal.ZonedDateTime")}} instances returns a positive integer representing the number of days in the year of this date. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+The set accessor of `daysInYear` is `undefined`. You cannot change this property directly.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/daysInYear", "Temporal.PlainDate.prototype.daysInYear")}}.
+
+## Examples
+
+### Using daysInYear
+
+```js
+const dt = Temporal.ZonedDateTime.from("2021-07-01[America/New_York]");
+console.log(dt.daysInYear); // 365
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/with", "Temporal.ZonedDateTime.prototype.with()")}}
+- {{jsxref("Temporal/ZonedDateTime/add", "Temporal.ZonedDateTime.prototype.add()")}}
+- {{jsxref("Temporal/ZonedDateTime/subtract", "Temporal.ZonedDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/ZonedDateTime/year", "Temporal.ZonedDateTime.prototype.year")}}
+- {{jsxref("Temporal/ZonedDateTime/dayOfYear", "Temporal.ZonedDateTime.prototype.dayOfYear")}}
+- {{jsxref("Temporal/ZonedDateTime/daysInMonth", "Temporal.ZonedDateTime.prototype.daysInMonth")}}
+- {{jsxref("Temporal/ZonedDateTime/daysInWeek", "Temporal.ZonedDateTime.prototype.daysInWeek")}}
+- {{jsxref("Temporal/PlainDate/daysInYear", "Temporal.PlainDate.prototype.daysInYear")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/epochmilliseconds/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/epochmilliseconds/index.md
new file mode 100644
index 000000000000000..b513d58215c25e2
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/epochmilliseconds/index.md
@@ -0,0 +1,59 @@
+---
+title: Temporal.ZonedDateTime.prototype.epochMilliseconds
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/epochMilliseconds
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.epochMilliseconds
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`epochMilliseconds`** accessor property of {{jsxref("Temporal.ZonedDateTime")}} instances returns an integer representing the number of milliseconds elapsed since the Unix epoch (midnight at the beginning of January 1, 1970, UTC) to this instant. It is equivalent to dividing `epochNanoseconds` by `1e6` and flooring the result.
+
+The set accessor of `epochMilliseconds` is `undefined`. You cannot change this property directly. To create a new `Temporal.ZonedDateTime` object with the desired new `epochMilliseconds` value, use the {{jsxref("Temporal/ZonedDateTime/add", "add()")}} or {{jsxref("Temporal/ZonedDateTime/subtract", "subtract()")}} method with the appropriate duration.
+
+## Examples
+
+### Using epochMilliseconds
+
+```js
+const instant = Temporal.ZonedDateTime.from("2021-08-01T12:34:56.789Z[UTC]");
+console.log(instant.epochMilliseconds); // 1627821296789
+
+const instant2 = Temporal.ZonedDateTime.from("1969-08-01T12:34:56.789Z[UTC]");
+console.log(instant2.epochMilliseconds); // -13173903211
+```
+
+### Creating a ZonedDateTime object from an epochMilliseconds value
+
+You can create a `Temporal.ZonedDateTime` object from an `epochMilliseconds` value by first constructing a `Temporal.Instant` object using {{jsxref("Temporal/Instant/fromEpochMilliseconds", "Temporal.Instant.fromEpochMilliseconds()")}}, and then converting it to a `Temporal.ZonedDateTime` object using {{jsxref("Temporal/Instant/toZonedDateTimeISO", "Temporal.Instant.prototype.toZonedDateTimeISO()")}}:
+
+```js
+const epochMilliseconds = 1627821296789;
+const instant = Temporal.Instant.fromEpochMilliseconds(epochMilliseconds);
+const zdt = instant.toZonedDateTimeISO("UTC");
+console.log(zdt.toString()); // 2021-08-01T12:34:56.789+00:00[UTC]
+```
+
+Alternatively, use the {{jsxref("Temporal/ZonedDateTime/ZonedDateTime", "Temporal.ZonedDateTime()")}} constructor, but convert the milliseconds to nanoseconds first:
+
+```js
+const epochMilliseconds = 1627821296789;
+const epochNanoseconds = BigInt(epochMilliseconds) * 1e6n;
+const zdt = new Temporal.ZonedDateTime(epochNanoseconds, "UTC");
+console.log(zdt.toString()); // 2021-08-01T12:34:56.789+00:00[UTC]
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/epochNanoseconds", "Temporal.ZonedDateTime.prototype.epochNanoseconds")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/epochnanoseconds/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/epochnanoseconds/index.md
new file mode 100644
index 000000000000000..fcf3d1f65b91f26
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/epochnanoseconds/index.md
@@ -0,0 +1,51 @@
+---
+title: Temporal.ZonedDateTime.prototype.epochNanoseconds
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/epochNanoseconds
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.epochNanoseconds
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`epochNanoseconds`** accessor property of {{jsxref("Temporal.ZonedDateTime")}} instances returns a {{jsxref("BigInt")}} representing the number of nanoseconds elapsed since the Unix epoch (midnight at the beginning of January 1, 1970, UTC) to this instant.
+
+The set accessor of `epochNanoseconds` is `undefined`. You cannot change this property directly. To create a new `Temporal.ZonedDateTime` object with the desired new `epochNanoseconds` value, use the {{jsxref("Temporal/ZonedDateTime/add", "add()")}} or {{jsxref("Temporal/ZonedDateTime/subtract", "subtract()")}} method with the appropriate duration.
+
+An instant can only represent ±10<sup>8</sup> days (about ±273,972.6 years) around the epoch, which is ±8.64e21 nanoseconds. Attempting to set `epochNanosecond` beyond this boundary throws a {{jsxref("RangeError")}}.
+
+## Examples
+
+### Using epochNanoseconds
+
+```js
+const instant = Temporal.ZonedDateTime.from("2021-08-01T12:34:56.789Z[UTC]");
+console.log(instant.epochNanoseconds); // 1627821296789000000n
+
+const instant2 = Temporal.ZonedDateTime.from("1969-08-01T12:34:56.789Z[UTC]");
+console.log(instant2.epochNanoseconds); // -13173903211000000n
+```
+
+### Creating a ZonedDateTime object from an epochNanoseconds value
+
+You can create a `Temporal.ZonedDateTime` object from an `epochNanoseconds` value using the {{jsxref("Temporal/ZonedDateTime/ZonedDateTime", "Temporal.ZonedDateTime()")}} constructor.
+
+```js
+const epochNanoseconds = 1627821296789000000n;
+const zdt = new Temporal.ZonedDateTime(epochNanoseconds, "UTC");
+console.log(zdt.toString()); // 2021-08-01T12:34:56.789+00:00[UTC]
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/epochMilliseconds", "Temporal.ZonedDateTime.prototype.epochMilliseconds")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/equals/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/equals/index.md
new file mode 100644
index 000000000000000..6dcd2730cd97d58
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/equals/index.md
@@ -0,0 +1,88 @@
+---
+title: Temporal.ZonedDateTime.prototype.equals()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/equals
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.equals
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`equals()`** method of {{jsxref("Temporal.ZonedDateTime")}} instances returns `true` if this date-time is equivalent in value to another date-time (in a form convertible by {{jsxref("Temporal/ZonedDateTime/from", "Temporal.ZonedDateTime.from()")}}), and `false` otherwise. They are compared both by their instant values, time zones, and their calendars, so two date-times from different calendars or time zones may be considered equal by {{jsxref("Temporal/ZonedDateTime/compare", "Temporal.ZonedDateTime.compare()")}} but not by `equals()`.
+
+## Syntax
+
+```js-nolint
+equals(other)
+```
+
+### Parameters
+
+- `other`
+  - : A string, an object, or a {{jsxref("Temporal.ZonedDateTime")}} instance representing the other date-time to compare. It is converted to a `Temporal.ZonedDateTime` object using the same algorithm as {{jsxref("Temporal/ZonedDateTime/from", "Temporal.ZonedDateTime.from()")}}.
+
+### Return value
+
+`true` if this date-time is equal to `other` both in their instant value, time zone, and their calendar, `false` otherwise.
+
+Note that the time zones are canonicalized before comparison, so if their [time zone IDs](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#time_zones_and_offsets) are both named and identify the same time zone, then they would be considered the same even when the exact names may be aliases of each other. Offset identifiers are compared by the offset values they represent. Offset identifiers never compare equal to named identifiers even when the named identifier's time zone always uses that offset.
+
+## Examples
+
+### Using equals()
+
+```js
+// Asia/Kolkata and Asia/Calcutta are aliases of each other
+const dt1 = Temporal.ZonedDateTime.from(
+  "2021-07-01T12:34:56+05:30[Asia/Kolkata]",
+);
+const dt2 = Temporal.ZonedDateTime.from(
+  "2021-07-01T12:34:56+05:30[Asia/Calcutta]",
+);
+console.log(dt1.equals(dt2)); // true
+
+const dt3 = Temporal.ZonedDateTime.from("2021-07-01T12:34:56+05:30[+05:30]");
+console.log(dt1.equals(dt3)); // false
+
+const dt4 = Temporal.ZonedDateTime.from(
+  "2021-07-01T12:34:56+05:30[Asia/Kolkata][u-ca=buddhist]",
+);
+console.log(dt1.equals(dt4)); // false
+```
+
+### Testing if two time zone identifiers are equivalent
+
+```js
+function sameTimeZone(timeZone1, timeZone2) {
+  const dt1 = Temporal.ZonedDateTime.from({
+    year: 2021,
+    month: 7,
+    day: 1,
+    timeZone: timeZone1,
+  });
+  const dt2 = Temporal.ZonedDateTime.from({
+    year: 2021,
+    month: 7,
+    day: 1,
+    timeZone: timeZone2,
+  });
+  return dt1.equals(dt2);
+}
+
+console.log(sameTimeZone("Asia/Kolkata", "Asia/Calcutta")); // true
+console.log(sameTimeZone("Asia/Shanghai", "Asia/Taipei")); // false
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/compare", "Temporal.ZonedDateTime.compare()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/era/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/era/index.md
new file mode 100644
index 000000000000000..5ba3a6fc006c63d
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/era/index.md
@@ -0,0 +1,48 @@
+---
+title: Temporal.ZonedDateTime.prototype.era
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/era
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.era
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`era`** accessor property of {{jsxref("Temporal.ZonedDateTime")}} instances returns a calendar-specific lowercase string representing the era of this date, or `undefined` if the calendar does not use eras (e.g. ISO 8601). `era` and `eraYear` together uniquely identify a year in a calendar, in the same way that `year` does. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+The set accessor of `era` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/ZonedDateTime/with", "with()")}} method to create a new `Temporal.ZonedDateTime` object with the desired new value.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/era", "Temporal.PlainDate.prototype.era")}}.
+
+## Examples
+
+### Using era
+
+```js
+const dt = Temporal.ZonedDateTime.from("2021-07-01[America/New_York]"); // ISO 8601 calendar
+console.log(dt.era); // undefined
+
+const dt2 = Temporal.ZonedDateTime.from(
+  "2021-07-01[America/New_York][u-ca=gregory]",
+);
+console.log(dt2.era); // gregory
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/with", "Temporal.ZonedDateTime.prototype.with()")}}
+- {{jsxref("Temporal/ZonedDateTime/add", "Temporal.ZonedDateTime.prototype.add()")}}
+- {{jsxref("Temporal/ZonedDateTime/subtract", "Temporal.ZonedDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/ZonedDateTime/year", "Temporal.ZonedDateTime.prototype.year")}}
+- {{jsxref("Temporal/ZonedDateTime/eraYear", "Temporal.ZonedDateTime.prototype.eraYear")}}
+- {{jsxref("Temporal/PlainDate/era", "Temporal.PlainDate.prototype.era")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/erayear/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/erayear/index.md
new file mode 100644
index 000000000000000..3b28b05e834ecac
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/erayear/index.md
@@ -0,0 +1,58 @@
+---
+title: Temporal.ZonedDateTime.prototype.eraYear
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/eraYear
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.eraYear
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`eraYear`** accessor property of {{jsxref("Temporal.ZonedDateTime")}} instances returns a non-negative integer representing the year of this date within the era, or `undefined` if the calendar does not use eras (e.g. ISO 8601). The year index usually starts from 1 (more common) or 0, and years in an era can decrease with time (e.g. Gregorian BCE). `era` and `eraYear` together uniquely identify a year in a calendar, in the same way that `year` does. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+The set accessor of `eraYear` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/ZonedDateTime/with", "with()")}} method to create a new `Temporal.ZonedDateTime` object with the desired new value.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/eraYear", "Temporal.PlainDate.prototype.eraYear")}}.
+
+## Examples
+
+### Using eraYear
+
+```js
+const dt = Temporal.ZonedDateTime.from("2021-07-01[America/New_York]"); // ISO 8601 calendar
+console.log(dt.eraYear); // undefined
+
+const dt2 = Temporal.ZonedDateTime.from(
+  "2021-07-01[America/New_York][u-ca=gregory]",
+);
+console.log(dt2.eraYear); // 2021
+
+const dt3 = Temporal.ZonedDateTime.from(
+  "-002021-07-01[America/New_York][u-ca=gregory]",
+);
+console.log(dt3.eraYear); // 2022; 0000 is used for the year 1 BC
+
+const dt4 = Temporal.ZonedDateTime.from(
+  "2021-07-01[America/New_York][u-ca=japanese]",
+);
+console.log(dt4.eraYear); // 3
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/with", "Temporal.ZonedDateTime.prototype.with()")}}
+- {{jsxref("Temporal/ZonedDateTime/add", "Temporal.ZonedDateTime.prototype.add()")}}
+- {{jsxref("Temporal/ZonedDateTime/subtract", "Temporal.ZonedDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/ZonedDateTime/year", "Temporal.ZonedDateTime.prototype.year")}}
+- {{jsxref("Temporal/ZonedDateTime/era", "Temporal.ZonedDateTime.prototype.era")}}
+- {{jsxref("Temporal/PlainDate/eraYear", "Temporal.PlainDate.prototype.eraYear")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/from/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/from/index.md
new file mode 100644
index 000000000000000..1c83636c972c38a
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/from/index.md
@@ -0,0 +1,163 @@
+---
+title: Temporal.ZonedDateTime.from()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/from
+page-type: javascript-static-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.from
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.ZonedDateTime.from()`** static method creates a new `Temporal.ZonedDateTime` object from another `Temporal.ZonedDateTime` object, an object with date, time, and time zone properties, or an [RFC 9557](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#rfc_9557_format) string.
+
+## Syntax
+
+```js-nolint
+Temporal.ZonedDateTime.from(info)
+Temporal.ZonedDateTime.from(info, options)
+```
+
+### Parameters
+
+- `info`
+  - : One of the following:
+    - A {{jsxref("Temporal.ZonedDateTime")}} instance, which creates a copy of the instance.
+    - An [RFC 9557 format](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#rfc_9557_format) string containing a date, optionally a time, optionally an offset, a time zone annotation, and optionally a calendar.
+    - An object containing properties that are accepted by either {{jsxref("Temporal/PlainDate/from", "Temporal.PlainDate.from()")}} (`calendar`, `era`, `eraYear`, `year`, `month`, `monthCode`, `day`) or {{jsxref("Temporal/PlainTime/from", "Temporal.PlainTime.from()")}} (`hour`, `minute`, `second`, `millisecond`, `microsecond`, `nanosecond`). The info should explicitly specify a year (as `year` or as `era` and `eraYear`), a month (as `month` or `monthCode`), and a day; others are optional and will be set to their default values. The following properties should be provided too:
+      - `timeZone`
+        - : Either a string or a {{jsxref("Temporal.ZonedDateTime")}} instance representing the time zone to use. If a `Temporal.ZonedDateTime` instance, its time zone is used. If a string, it can be a named time zone identifier, an offset time zone identifier, or a date-time string containing a time zone identifier or an offset (see [time zones and offsets](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#time_zones_and_offsets) for more information). The time properties are interpreted in this time zone.
+      - `offset` {{optional_inline}}
+        - : A offset string, in the same format as the [RFC 9557](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#rfc_9557_format) offset (`±HH:mm:ss.sssssssss`), representing the offset from UTC. If omitted, it will be calculated from the time zone and the date-time. `"Z"` is not allowed.
+- `options` {{optional_inline}}
+  - : An object containing some or all of the following properties (in the order they are retrieved and validated):
+    - `disambiguation` {{optional_inline}}
+      - : What to do if the local date-time is ambiguous in the given time zone (there are more than one instants with such local time, or the local time does not exist). Possible values are `"compatible"`, `"earlier"`, `"later"`, and `"reject"`. Defaults to `"compatible"`. For more information about these values, see [ambiguity and gaps from local time to UTC time](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#ambiguity_and_gaps_from_local_time_to_utc_time).
+    - `offset` {{optional_inline}}
+      - : What to do if the offset is explicitly provided in `info` but the offset is invalid for the given time zone in the given local time. Possible values are `"use"`, `"ignore"`, `"reject"`, and `"prefer"`. Defaults to `"reject"`. For more information about these values, see [offset ambiguity](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#offset_ambiguity).
+    - `overflow` {{optional_inline}}
+      - : A string specifying the behavior when a date component is out of range (when using the object `info`). Possible values are:
+        - `"constrain"` (default)
+          - : The date component is [clamped](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate#invalid_date_clamping) to the valid range.
+        - `"reject"`
+          - : A {{jsxref("RangeError")}} is thrown if the date component is out of range.
+
+### Return value
+
+A new `Temporal.ZonedDateTime` object, representing the date and time specified by `info` in the specified `calendar` and `timeZone`.
+
+### Exceptions
+
+- {{jsxref("TypeError")}}
+  - : Thrown in one of the following cases:
+    - `info` is not an object or a string.
+    - `options` is not an object or `undefined`.
+    - The provided properties are insufficient to unambiguously determine a date. You usually need to provide a `year` (or `era` and `eraYear`), a `month` (or `monthCode`), and a `day`.
+- {{jsxref("RangeError")}}
+  - : Thrown in one of the following cases:
+    - The provided properties that specify the same component are inconsistent.
+    - The provided non-numerical properties are not valid; for example, if `monthCode` is never a valid month code in this calendar.
+    - The provided numerical properties are out of range, and `options.overflow` is set to `"reject"`.
+
+## Examples
+
+### Creating a ZonedDateTime from an object
+
+```js
+// Year + month + day + hour + minute + second
+const zdt = Temporal.ZonedDateTime.from({
+  timeZone: "America/New_York",
+  year: 2021,
+  month: 7,
+  day: 1,
+  hour: 12,
+  minute: 34,
+  second: 56,
+});
+console.log(zdt.toString()); // "2021-07-01T12:34:56-04:00[America/New_York]"
+```
+
+### Creating a ZonedDateTime from a string
+
+```js
+const zdt = Temporal.ZonedDateTime.from(
+  "2021-07-01T12:34:56-04:00[America/New_York]",
+);
+console.log(zdt.toLocaleString()); // "7/1/2021, 12:34:56 PM EDT" (assuming en-US locale)
+
+// Time given as UTC, and converted to local
+const zdt2 = Temporal.ZonedDateTime.from(
+  "2021-07-01T12:34:56Z[America/New_York]",
+);
+console.log(zdt2.toString()); // "2021-07-01T08:34:56-04:00[America/New_York]"
+```
+
+### Creating a ZonedDateTime from an ISO 8601 / RFC 3339 string
+
+Note that `Temporal.ZonedDateTime.from()` rejects ISO 8601 strings, which do not include a time zone identifier. This is to ensure that the time zone is always known and can be used to derive different offsets as the local time changes.
+
+If you want to parse an ISO 8601 string, first construct a {{jsxref("Temporal.Instant")}} object and then convert it to a `Temporal.ZonedDateTime` object. You can provide any time zone, even if it doesn't match the offset originally given in the string, and the local time will be adjusted accordingly.
+
+```js
+const isoString = "2021-07-01T12:34:56+02:00";
+const instant = Temporal.Instant.from(isoString);
+const zdt = instant.toZonedDateTimeISO("America/New_York");
+console.log(zdt.toString()); // "2021-07-01T06:34:56-04:00[America/New_York]"
+```
+
+### Local time disambiguation
+
+See [ambiguity and gaps from local time to UTC time](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#ambiguity_and_gaps_from_local_time_to_utc_time) for an introduction to this situation.
+
+```js
+const localTimeNotExist = "2024-03-10T02:05:00[America/New_York]";
+// For non-existent times, "compatible" is equivalent to "later"
+const zdt = Temporal.ZonedDateTime.from(localTimeNotExist);
+console.log(zdt.toString()); // "2024-03-10T03:05:00-04:00[America/New_York]"
+
+const zdt2 = Temporal.ZonedDateTime.from(localTimeNotExist, {
+  disambiguation: "earlier",
+});
+console.log(zdt2.toString()); // "2024-03-10T01:05:00-05:00[America/New_York]"
+
+const localTimeAmbiguous = "2024-11-03T01:05:00[America/New_York]";
+// For ambiguous times, "compatible" is equivalent to "earlier"
+const zdt3 = Temporal.ZonedDateTime.from(localTimeAmbiguous);
+console.log(zdt3.toString()); // "2024-11-03T01:05:00-04:00[America/New_York]"
+
+const zdt4 = Temporal.ZonedDateTime.from(localTimeAmbiguous, {
+  disambiguation: "later",
+});
+console.log(zdt4.toString()); // "2024-11-03T01:05:00-05:00[America/New_York]"
+```
+
+### Resolving offset ambiguity
+
+See [offset ambiguity](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#offset_ambiguity) for an introduction to this situation.
+
+```js
+const offsetAmbiguous = "2019-12-23T12:00:00-02:00[America/Sao_Paulo]";
+
+Temporal.ZonedDateTime.from(offsetAmbiguous);
+// RangeError: date-time can't be represented in the given time zone
+Temporal.ZonedDateTime.from(offsetAmbiguous, { offset: "use" }).toString();
+// "2019-12-23T11:00:00-03:00[America/Sao_Paulo]"
+Temporal.ZonedDateTime.from(offsetAmbiguous, { offset: "ignore" }).toString();
+// "2019-12-23T12:00:00-03:00[America/Sao_Paulo]"
+```
+
+For more examples, especially regarding different calendars and overflow settings, see {{jsxref("Temporal/PlainDate/from", "Temporal.PlainDate.from()")}} and {{jsxref("Temporal/PlainTime/from", "Temporal.PlainTime.from()")}}.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/ZonedDateTime", "Temporal.ZonedDateTime()")}}
+- {{jsxref("Temporal/ZonedDateTime/with", "Temporal.ZonedDateTime.prototype.with()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/gettimezonetransition/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/gettimezonetransition/index.md
new file mode 100644
index 000000000000000..1e77c3f8f1211bc
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/gettimezonetransition/index.md
@@ -0,0 +1,76 @@
+---
+title: Temporal.ZonedDateTime.prototype.getTimeZoneTransition()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/getTimeZoneTransition
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.getTimeZoneTransition
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`getTimeZoneTransition()`** method of {{jsxref("Temporal.ZonedDateTime")}} instances returns a {{jsxref("Temporal.ZonedDateTime")}} object representing the closest instant after or before this instant at which the time zone's UTC offset changes (the returned instant is the first instant after the change), or `null` if there is no such transition. This is useful for finding out the offset rules of a time zone, such as its daylight saving time pattern.
+
+Note that instants returned about the future may be unreliable, for example due to changes to the time zone definitions.
+
+## Syntax
+
+```js-nolint
+getTimeZoneTransition(direction)
+getTimeZoneTransition(options)
+```
+
+### Parameters
+
+- `direction`
+  - : A string representing the [`direction`](#direction_2) option. This is a convenience overload, so `getTimeZoneTransition(direction)` is equivalent to `round({ direction })`, where `direction` is a string.
+- `options`
+  - : An object containing the following property:
+    - `direction`
+      - : Whether to search before or after the current instant. Must be one of `"next"` or `"previous"`.
+
+### Return value
+
+A {{jsxref("Temporal.ZonedDateTime")}} object with instant `t`, such that:
+
+- The time zone offset at `t` is different from the offset one nanosecond before `t`.
+- `t < this.epochNanoseconds` if `direction` is `"previous"`, or `t > this.epochNanoseconds` if `direction` is `"next"`.
+- For all instants between `this.epochNanoseconds` and `t`, exclusive, the offset is constant.
+
+If there is no such transition, `null` is returned.
+
+## Examples
+
+### Finding the next time zone transition
+
+```js
+const dt = Temporal.ZonedDateTime.from("2024-01-01T00-05:00[America/New_York]");
+const transition = dt.getTimeZoneTransition("next");
+console.log(transition.toString()); // "2024-03-10T03:00:00-04:00[America/New_York]"
+
+const transition2 = transition.getTimeZoneTransition("next");
+console.log(transition2.toString()); // "2024-11-03T01:00:00-05:00[America/New_York]"
+
+const transition3 = dt.getTimeZoneTransition("previous");
+console.log(transition3.toString()); // "2023-11-05T01:00:00-05:00[America/New_York]"
+
+const dt2 = Temporal.ZonedDateTime.from("2024-01-01T00Z[UTC]");
+console.log(dt2.getTimeZoneTransition("next")); // null
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/with", "Temporal.ZonedDateTime.prototype.with()")}}
+- {{jsxref("Temporal/ZonedDateTime/add", "Temporal.ZonedDateTime.prototype.add()")}}
+- {{jsxref("Temporal/ZonedDateTime/subtract", "Temporal.ZonedDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/ZonedDateTime/timeZoneId", "Temporal.ZonedDateTime.prototype.timeZoneId")}}
+- {{jsxref("Temporal/ZonedDateTime/offset", "Temporal.ZonedDateTime.prototype.offset")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/hour/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/hour/index.md
new file mode 100644
index 000000000000000..096c0f7330a6de0
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/hour/index.md
@@ -0,0 +1,69 @@
+---
+title: Temporal.ZonedDateTime.prototype.hour
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/hour
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.hour
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`hour`** accessor property of {{jsxref("Temporal.ZonedDateTime")}} instances returns a integer from 0 to 23 representing the hour component of this time.
+
+The set accessor of `hour` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/ZonedDateTime/with", "with()")}} method to create a new `Temporal.ZonedDateTime` object with the desired new value.
+
+For general information and more examples, see {{jsxref("Temporal/PlainTime/hour", "Temporal.PlainTime.prototype.hour")}}.
+
+For `ZonedDateTime`, `hour` can be non-continuous due to offset changes such as daylight saving time transitions. In this case, the hour may be repeated or skipped.
+
+## Examples
+
+### Using hour
+
+```js
+const dt = Temporal.ZonedDateTime.from(
+  "2021-07-01T12:34:56.123456789-04:00[America/New_York]",
+);
+console.log(dt.hour); // 12
+```
+
+### Non-continuous hour
+
+Non-continuous hour is very common due to daylight saving time transitions, which is explained more in [Ambiguity and gaps from local time to UTC time](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#ambiguity_and_gaps_from_local_time_to_utc_time).
+
+```js
+const dt = Temporal.ZonedDateTime.from(
+  "2024-11-03T01:59:00-04:00[America/New_York]",
+);
+console.log(dt.hour); // 1
+const dt2 = dt.add({ minutes: 1 });
+console.log(dt2.hour); // 1
+console.log(dt2.toString()); // 2024-11-03T01:00:00-05:00[America/New_York]
+
+const dt3 = Temporal.ZonedDateTime.from(
+  "2024-03-10T01:59:00-05:00[America/New_York]",
+);
+console.log(dt3.hour); // 1
+const dt4 = dt3.add({ minutes: 1 });
+console.log(dt4.hour); // 3
+console.log(dt4.toString()); // 2024-03-10T03:00:00-04:00[America/New_York]
+```
+
+For this reason, you should always prefer {{jsxref("Temporal/ZonedDateTime/add", "add()")}} and {{jsxref("Temporal/ZonedDateTime/subtract", "subtract()")}} to manipulate dates and times, rather than directly changing the `hour` property.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/with", "Temporal.ZonedDateTime.prototype.with()")}}
+- {{jsxref("Temporal/ZonedDateTime/add", "Temporal.ZonedDateTime.prototype.add()")}}
+- {{jsxref("Temporal/ZonedDateTime/subtract", "Temporal.ZonedDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainTime/hour", "Temporal.PlainTime.prototype.hour")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/hoursinday/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/hoursinday/index.md
new file mode 100644
index 000000000000000..d564d457cf84673
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/hoursinday/index.md
@@ -0,0 +1,56 @@
+---
+title: Temporal.ZonedDateTime.prototype.hoursInDay
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/hoursInDay
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.hoursInDay
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`hoursInDay`** accessor property of {{jsxref("Temporal.ZonedDateTime")}} instances returns a positive integer representing the number of hours in the day of this date in the time zone. It may be more or less than 24 in the case of offset changes such as daylight saving time.
+
+Because `ZonedDateTime` is the only class that's time zone-aware, and hours in a day can only change by offset changes, all other classes assume 24-hour days.
+
+The set accessor of `hoursInDay` is `undefined`. You cannot change this property directly.
+
+## Examples
+
+### Using hoursInDay
+
+```js
+const dt = Temporal.ZonedDateTime.from(
+  "2024-03-10T01:58:00-05:00[America/New_York]",
+);
+console.log(dt.hoursInDay); // 23; this is the day of transition into DST
+
+const dt2 = Temporal.ZonedDateTime.from(
+  "2024-11-03T01:58:00-04:00[America/New_York]",
+);
+console.log(dt2.hoursInDay); // 25; this is the day of transition out of DST
+
+const dt3 = Temporal.ZonedDateTime.from(
+  "2024-11-04T01:58:00-05:00[America/New_York]",
+);
+console.log(dt3.hoursInDay); // 24
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/with", "Temporal.ZonedDateTime.prototype.with()")}}
+- {{jsxref("Temporal/ZonedDateTime/add", "Temporal.ZonedDateTime.prototype.add()")}}
+- {{jsxref("Temporal/ZonedDateTime/subtract", "Temporal.ZonedDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/ZonedDateTime/hour", "Temporal.ZonedDateTime.prototype.hour")}}
+- {{jsxref("Temporal/ZonedDateTime/dayOfYear", "Temporal.ZonedDateTime.prototype.dayOfYear")}}
+- {{jsxref("Temporal/ZonedDateTime/daysInMonth", "Temporal.ZonedDateTime.prototype.daysInMonth")}}
+- {{jsxref("Temporal/ZonedDateTime/daysInWeek", "Temporal.ZonedDateTime.prototype.daysInWeek")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/index.md
new file mode 100644
index 000000000000000..12730d179dec147
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/index.md
@@ -0,0 +1,303 @@
+---
+title: Temporal.ZonedDateTime
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime
+page-type: javascript-class
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.ZonedDateTime`** object represents a date and time with a time zone. It is fundamentally represented as a combination of an [instant](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Instant), a time zone, and a calendar system.
+
+## Description
+
+A `ZonedDateTime` functions as a bridge between an exact time and a wall-clock time: it simultaneously represents an instant in history (like a {{jsxref("Temporal.Instant")}}) and a local, wall-clock time (like a {{jsxref("Temporal.PlainDateTime")}}). It does so by storing the instant, the time zone, and the calendar system. The time zone is used to convert between the instant and the local time, and the calendar system is used to interpret the local time.
+
+`ZonedDateTime` is the only `Temporal` class that is time zone-aware. The addition of a time zone makes `ZonedDateTime` objects have important behavior differences from {{jsxref("Temporal.PlainDateTime")}} objects. Namely, you can no longer assume that "the time 1 minute afterwards" is the same every day, or that a day has 24 hours. In the worst case, an entire day may be missing from the local calendar. Below, we offer a quick overview of time zones and offsets and how they affect conversion between UTC time and local time.
+
+### Time zones and offsets
+
+All times in JavaScript have one golden standard: the UTC time, which increments continuously and uniformly as physical time progresses. By contrast, users are more interested in their local time, which is the time they read on their calendars and clocks. The process of converting between UTC time and local time involves a time zone _offset_, which is calculated as:
+
+```plain
+local time = UTC time + offset
+```
+
+For example, if the UTC time is 1970-01-01T00:00:00, and the offset is "-05:00", then the local time is:
+
+```plain
+1970-01-01T00:00:00 + -05:00 = 1969-12-31T19:00:00
+```
+
+By suffixing this local time with the offset, thus expressing this time as "1969-12-31T19:00:00-05:00", it can now be unambiguously understood as an instant in history.
+
+To know the offset, we need two pieces of information, the _time zone_, and the _instant_. The time zone is a region on Earth where the same offset is used at all times. Two clocks in the same time zone will always show the same time simultaneously, but the offset is not necessarily constant: that is, these clocks' times may change abruptly. This commonly happens during daylight saving time transitions, where the offset changes by an hour, which happens twice a year. Offsets can also change permanently due to political changes, e.g., a country switching time zones.
+
+The time zones are stored in the [IANA Time Zone Database](https://www.iana.org/time-zones). Each IANA time zone has:
+
+- A _primary time zone identifier_ that uniquely identifies the time zone. It usually refers to a geographic area anchored by a city (e.g. `Europe/Paris` or `Africa/Kampala`), but can also denote single-offset time zones like `UTC` (a consistent `+00:00` offset) or `Etc/GMT+5` (which for historical reasons is a negative offset `-05:00`). For historical reasons, the primary name for the UTC time zone is `UTC`, though in IANA it is `Etc/UTC`.
+- A _time zone definition_ in the form of a table that maps UTC date/time ranges (including future ranges) to specific offsets.
+- Zero or more _non-primary time zone identifiers_ that are aliases to the primary time zone identifier. These are usually historical names that are no longer in use, but are kept for compatibility reasons. See below for more information.
+
+As input, named identifiers are matched case-insensitively. Internally, they are stored in their preferred case, and non-primary identifiers will _not_ be converted to their primary identifier.
+
+> [!NOTE]
+> When setting the time zone name, you rarely want to set it to `"UTC"`. `ZonedDateTime` is intended to be displayed to users, but no human lives in the "UTC" time zone. If you don't know the time zone at construction time but know the wall-clock time, use a {{jsxref("Temporal.PlainDateTime")}}. If you know the exact instant, use a {{jsxref("Temporal.Instant")}}.
+
+When a `Temporal` API accepts a _time zone identifier_, in addition to primary time zone identifiers and non-primary time zone identifiers, it also accepts an _offset time zone identifier_, which is in the same form as the offset, except subminute precision is not allowed. For example, `+05:30`, `-08`, `+0600` are all valid offsets identifiers. Internally, offset identifiers are stored in the `±HH:mm` form.
+
+> [!NOTE]
+> Avoid using offset identifiers if there is a named time zone you can use instead. Even if a region has always used a single offset, it is better to use the named identifier to guard against future political changes to the offset.
+>
+> If a region uses (or has used) multiple offsets, then using its named time zone is even more important. This is because `Temporal.ZonedDateTime` can use methods like `add` or `with` to create new instances at a different instant. If those derived instances correspond to an instant that uses a different offset (for example, after a Daylight Saving Time transition) then your calculations will have an incorrect local time. Using a named time zone ensures that local dates and times are always adjusted for the correct offset for that instant.
+
+For convenience, when providing a time zone identifier to `Temporal` APIs such as `Temporal.ZonedDateTime.prototype.withTimeZone()` and the `timeZoneId` option of `Temporal.ZonedDateTime.from()`, you can provide it in a few other forms:
+
+- As another `ZonedDateTime` instance, whose `timeZoneId` will be used.
+- As an [RFC 9557 string](#rfc_9557_format) with a time zone annotation, whose time zone identifier will be used.
+- As an ISO 8601 / RFC 3339 string containing an offset, whose offset will be used as an offset identifier; or, if using `Z`, then the `"UTC"` time zone is used. This usage is generally not recommended, because as discussed above, offset identifiers lack the ability to safely derive other `Temporal.ZonedDateTime` instances across an offset transition like when daylight saving time starts or ends. Instead, consider just using `Temporal.Instant` or fetching the user's actual named time zone.
+
+The IANA time zone database changes from time to time, usually to add new time zones in response to political changes. However, on rare occasions, IANA time zone identifiers are renamed to match updated English translation of a city name or to update outdated naming conventions. For example, here are a few notable name changes:
+
+| Current IANA primary identifier  | Old, now non-primary identifier |
+| -------------------------------- | ------------------------------- |
+| `America/Argentina/Buenos_Aires` | `America/Buenos_Aires`          |
+| `Asia/Kolkata`                   | `Asia/Calcutta`                 |
+| `Asia/Ho_Chi_Minh`               | `Asia/Saigon`                   |
+| `Europe/Kyiv`                    | `Europe/Kiev`                   |
+
+Historically, these renames caused problems for programmers because the the Unicode [CLDR database](https://github.com/unicode-org/cldr-json/blob/main/cldr-json/cldr-bcp47/bcp47/timezone.json) (a library used by browsers rely on to supply time zone identifiers and data) did not follow IANA's renaming for [stability reasons](https://unicode.org/reports/tr35/#Time_Zone_Identifiers). As a result, some browsers like Chrome and Safari reported CLDR's outdated identifiers, while other browsers like Firefox overrode CLDR's defaults and reported the up-to-date primary identifiers.
+
+With the introduction of Temporal, this behavior is now more standardized:
+
+- [CLDR data](https://github.com/unicode-org/cldr-json/blob/main/cldr-json/cldr-bcp47/bcp47/timezone.json) now includes an `"_iana"` attribute that indicates the most up-to-date identifier if the older, stable identifier has been renamed. Browsers can use this new attribute to provide up-to-date identifiers to callers.
+- Time zone identifiers provided by the programmer will never be replaced with an alias. For example, if the caller provides `Asia/Calcutta` or `Asia/Kolkata` as the identifier input to `Temporal.ZonedDateTime.from()`, then the same identifier is returned in the resulting instance's `timeZoneId`. Note that the letter case of outputs are normalized to match IANA, so that `ASIA/calCuTTa` as input generates a `timeZoneId` of `Asia/Calcutta` as output.
+- When a time zone identifier is not provided by a caller but is instead sourced from the system itself (for example, when using `Temporal.Now.timeZoneId()`), modern identifiers are returned in all browsers. For city renames, there is a two-year lag before these system-provided-identifier APIs expose the new name, thereby giving other components (like a Node server) time to update their copies of the IANA database to recognize the new name.
+
+Note that the attribution of primary identifiers preserves the country code: for example, the IANA database records `Atlantic/Reykjavik` as an alias for `Africa/Abidjan`, but because they correspond to different countries (Iceland and Côte d'Ivoire, respectively), they are treated as distinct primary identifiers.
+
+This standardization applies outside of `Temporal` as well. For example, the `timeZone` option returned by {{jsxref("Intl/DateTimeFormat/resolvedOptions", "Intl.DateTimeFormat.prototype.resolvedOptions()")}} is also never replaced with an alias, though browsers have traditionally canonicalized these identifiers prior to standardization by Temporal. On the other hand, {{jsxref("Intl/Locale/getTimeZones", "Intl.Locale.prototype.getTimeZones()")}} and {{jsxref("Intl.supportedValuesOf()")}} (`timeZone` option) will return the most up-to-date identifier, while some browsers used to return the old, non-primary identifier.
+
+### RFC 9557 format
+
+`ZonedDateTime` objects can be serialized and parsed using the [RFC 9557](https://datatracker.ietf.org/doc/html/rfc9557) format, an extension to the [ISO 8601 / RFC 3339](https://datatracker.ietf.org/doc/html/rfc3339) format. The string has the following form (spaces are only for readability and should not be present in the actual string):
+
+```plain
+YYYY-MM-DD T HH:mm:ss.sssssssss Z/±HH:mm:ss.sssssssss [time_zone_id] [u-ca=calendar_id]
+```
+
+- `YYYY`
+  - : Either a four-digit number, or a six-digit number with a `+` or `-` sign.
+- `MM`
+  - : A two-digit number from `01` to `12`.
+- `DD`
+  - : A two-digit number from `01` to `31`. The `YYYY`, `MM`, and `DD` components can be separated by `-` or nothing.
+- `T` {{optional_inline}}
+  - : The date-time separator, which can be `T`, `t`, or a space. Present if and only if `HH` is present.
+- `HH` {{optional_inline}}
+  - : A two-digit number from `00` to `23`. Defaults to `00`.
+- `mm` {{optional_inline}}
+  - : A two-digit number from `00` to `59`. Defaults to `00`.
+- `ss.sssssssss` {{optional_inline}}
+  - : A two-digit number from `00` to `59`. May optionally be followed by a `.` or `,` and one to nine digits. Defaults to `00`. The `HH`, `mm`, and `ss` components can be separated by `:` or nothing. You can omit either just `ss` or both `ss` and `mm`, so the time can be one of three forms: `HH`, `HH:mm`, or `HH:mm:ss.sssssssss`.
+- `Z/±HH:mm:ss.sssssssss` {{optional_inline}}
+  - : Either the UTC designator `Z` or `z`, or an offset from UTC in the form `+` or `-` followed by the same format as the time component. Note that subminute precision may be unsupported by other systems. If omitted, the offset is derived from the time zone identifier. If present, then the time must be provided too. `Z` is not the same as `+00:00`: the former means that the time is given in UTC form regardless of the time zone identifier, while the latter means that the time is given in local time which happens to be UTC+0, and will be validated against the time zone identifier via the [`offset` option](#offset_ambiguity).
+- `[time_zone_id]`
+  - : Replace `time_zone_id` with the time zone identifier (named or offset) as described above. May have a _critical flag_ by prefixing the identifier with `!`: e.g., `[!America/New_York]`. This flag generally tells other systems that it cannot be ignored if they don't support it. Note that it is required for `Temporal.ZonedDateTime.from()`: omitting it causes a `RangeError`. If you want to parse ISO 8601 / RFC 3339 strings without time zone identifier annotations, use {{jsxref("Temporal/Instant/from", "Temporal.Instant.from()")}} instead.
+- `[u-ca=calendar_id]` {{optional_inline}}
+  - : Replace `calendar_id` with the calendar to use. May have a _critical flag_ by prefixing the key with `!`: e.g., `[!u-ca=iso8601]`. This flag generally tells other systems that it cannot be ignored if they don't support it. The `Temporal` parser will throw an error if the annotations contain two or more calendar annotations and one of them is critical. Defaults to `[u-ca=iso8601]`. Note that the `YYYY-MM-DD` is always interpreted as an ISO 8601 calendar date and then converted to the specified calendar.
+
+As an input, other annotations in the `[key=value]` format are ignored, and they must not have the critical flag.
+
+When serializing, you can configure the fractional second digits, whether to display the offset/time zone ID/calendar ID, and whether to add a critical flag for the annotations.
+
+### Ambiguity and gaps from local time to UTC time
+
+Given a time zone, conversion from UTC to local time is straightforward: you first get the offset using the time zone name and the instant, then add the offset to the instant. The reverse is not true: conversion from local time to UTC time, without an explicit offset, is ambiguous, because one local time can correspond to zero, one, or many UTC times. Consider the most common cause: daylight saving time transitions. Take New York as an example. Its standard offset is UTC-5, but during DST, all clocks are set forward by an hour, so the offset becomes UTC-4. In the US, transitions happen at 2:00 AM local time, so consider these two transition days:
+
+| UTC time             | New York time             |
+| -------------------- | ------------------------- |
+| 2024-03-10T06:58:00Z | 2024-03-10T01:58:00-05:00 |
+| 2024-03-10T06:59:00Z | 2024-03-10T01:59:00-05:00 |
+| 2024-03-10T07:00:00Z | 2024-03-10T03:00:00-04:00 |
+| ---                  | ---                       |
+| 2024-11-03T05:58:00Z | 2024-11-03T01:58:00-04:00 |
+| 2024-11-03T05:59:00Z | 2024-11-03T01:59:00-04:00 |
+| 2024-11-03T06:00:00Z | 2024-11-03T01:00:00-05:00 |
+
+As you can see, in March, one hour disappeared from the local time, and in November, we have two hours that have the same wall-clock time. Suppose that we stored a `PlainDateTime` that says "2024-03-10T02:05:00", and we want to interpret it in the `America/New_York` time zone, there will be no time that corresponds to it, while a `PlainDateTime` that says "2024-11-03T01:05:00" can correspond to two different instants.
+
+When constructing a `ZonedDateTime` from a local time (using {{jsxref("Temporal/ZonedDateTime/from", "Temporal.ZonedDateTime.from()")}}, {{jsxref("Temporal/ZonedDateTime/with", "Temporal.ZonedDateTime.prototype.with()")}}, {{jsxref("Temporal/PlainDateTime/toZonedDateTime", "Temporal.PlainDateTime.prototype.toZonedDateTime()")}}), the behavior for ambiguity and gaps is configurable via the `disambiguation` option:
+
+- `earlier`
+  - : If there are two possible instants, choose the earlier one. If there is a gap, go back by the gap duration.
+- `later`
+  - : If there are two possible instants, choose the later one. If there is a gap, go forward by the gap duration.
+- `compatible` (default)
+  - : Same behavior as {{jsxref("Date")}}: use `later` for gaps and `earlier` for ambiguities.
+- `reject`
+  - : Throw a `RangeError` whenever there is an ambiguity or a gap.
+
+There are several cases where there's no ambiguity when constructing a `ZonedDateTime`:
+
+- If the time is specified in UTC via the `Z` offset.
+- If the offset is explicitly provided and used (see below).
+
+### Offset ambiguity
+
+We already demonstrated how ambiguity may arise from interpreting a local time in a time zone, without providing an explicit offset. However, if you provide an explicit offset, then another conflict arises: between the offset as specified, and the offset as calculated from the time zone and the local time. This is an unavoidable real-world issue: if you store a time in the future, with an anticipated offset, then before that time comes, the time zone definition may have changed due to political reasons. For example, suppose in 2018, we set a reminder at the time `2019-12-23T12:00:00-02:00[America/Sao_Paulo]` (which is a daylight saving time; Brazil is in the southern hemisphere, so it enters DST in October and exits in February). But before that time comes, in early 2019, Brazil decides to stop observing DST, so the real offset becomes `-03:00`. Should the reminder now still fire at noon (keeping the local time), or should it fire at 11:00 AM (keeping the exact time)?
+
+When constructing a `ZonedDateTime` with {{jsxref("Temporal/ZonedDateTime/from", "Temporal.ZonedDateTime.from()")}} or when updating it using the {{jsxref("Temporal/ZonedDateTime/with", "with()")}} method, the behavior for offset ambiguity is configurable via the `offset` option:
+
+- `use`
+  - : Use the offset to calculate the exact time. This option "uses" the offset when determining the instant represented by the string, which will be the same instant originally calculated when we stored the time, even if the offset at that instant has changed. The time zone identifier is still used to then infer the (possibly updated) offset and use that offset to convert the exact time to local time.
+- `ignore`
+  - : Use the time zone identifier to re-calculate the offset, ignoring the offset that's specified in the string. This option keeps the same local time as originally calculated when we stored the time, but may correspond to a different instant. Note that this option may cause the same local time interpretation ambiguity as demonstrated above, which is resolved using the `disambiguation` option.
+- `reject`
+  - : Throw a `RangeError` whenever there is a conflict between the offset and the time zone identifier. This is the default for {{jsxref("Temporal/ZonedDateTime/from", "Temporal.ZonedDateTime.from()")}}.
+- `prefer`
+  - : Use the offset if it's valid, otherwise calculate the offset from the time zone identifier. This is the default for {{jsxref("Temporal/ZonedDateTime/with", "Temporal.ZonedDateTime.prototype.with()")}} (see the method for more details). This is different from `ignore` because in the case of local time ambiguity, the offset is used to resolve it rather than the `disambiguation` option.
+
+Note that the `Z` offset does not mean `+00:00`; it is always considered valid regardless of the time zone. The time is interpreted as a UTC time, and the time zone identifier is then used to convert it to local time. In other words, `Z` enforces the same behavior as the `ignore` option and its results can never be ambiguous.
+
+> [!NOTE]
+> Although {{jsxref("Temporal/Instant/from", "Temporal.Instant.from()")}} also takes an [RFC 9557](#rfc_9557_format) string in the same form, there is no ambiguity because it always ignores the time zone identifier and reads the offset only.
+
+## Constructor
+
+- {{jsxref("Temporal/ZonedDateTime/ZonedDateTime", "Temporal.ZonedDateTime()")}} {{experimental_inline}}
+  - : Creates a new `Temporal.ZonedDateTime` object by directly supplying the underlying data.
+
+## Static methods
+
+- {{jsxref("Temporal/ZonedDateTime/compare", "Temporal.ZonedDateTime.compare()")}} {{experimental_inline}}
+  - : Returns a number (-1, 0, or 1) indicating whether the first date-time comes before, is the same as, or comes after the second date-time. Equivalent to comparing the {{jsxref("Temporal/ZonedDateTime/epochNanoseconds", "epochNanoseconds")}} of the two datetimes.
+- {{jsxref("Temporal/ZonedDateTime/from", "Temporal.ZonedDateTime.from()")}} {{experimental_inline}}
+  - : Creates a new `Temporal.ZonedDateTime` object from another `Temporal.ZonedDateTime` object, an object with date, time, and time zone properties, or an [RFC 9557](#rfc_9557_format) string.
+
+## Instance properties
+
+These properties are defined on `Temporal.ZonedDateTime.prototype` and shared by all `Temporal.ZonedDateTime` instances.
+
+- {{jsxref("Temporal/ZonedDateTime/calendarId", "Temporal.ZonedDateTime.prototype.calendarId")}} {{experimental_inline}}
+  - : Returns a string representing the [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars) used to interpret the internal ISO 8601 date.
+- {{jsxref("Object/constructor", "Temporal.ZonedDateTime.prototype.constructor")}}
+  - : The constructor function that created the instance object. For `Temporal.ZonedDateTime` instances, the initial value is the {{jsxref("Temporal/ZonedDateTime/ZonedDateTime", "Temporal.ZonedDateTime()")}} constructor.
+- {{jsxref("Temporal/ZonedDateTime/day", "Temporal.ZonedDateTime.prototype.day")}} {{experimental_inline}}
+  - : Returns a positive integer representing the 1-based day index in the month of this date, which is the same day number you would see on a calendar. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. Generally starts at 1 and is continuous, but not always.
+- {{jsxref("Temporal/ZonedDateTime/dayOfWeek", "Temporal.ZonedDateTime.prototype.dayOfWeek")}} {{experimental_inline}}
+  - : Returns a positive integer representing the 1-based day index in the week of this date. Days in a week are numbered sequentially from `1` to {{jsxref("Temporal/ZonedDateTime/daysInWeek", "daysInWeek")}}, with each number mapping to its name. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. 1 usually represents Monday in the calendar, even when locales using the calendar may consider a different day as the first day of the week (see {{jsxref("Intl/Locale/getWeekInfo", "Intl.Locale.prototype.getWeekInfo()")}}).
+- {{jsxref("Temporal/ZonedDateTime/dayOfYear", "Temporal.ZonedDateTime.prototype.dayOfYear")}} {{experimental_inline}}
+  - : Returns a positive integer representing the 1-based day index in the year of this date. The first day of this year is `1`, and the last day is the {{jsxref("Temporal/ZonedDateTime/daysInYear", "daysInYear")}}. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+- {{jsxref("Temporal/ZonedDateTime/daysInMonth", "Temporal.ZonedDateTime.prototype.daysInMonth")}} {{experimental_inline}}
+  - : Returns a positive integer representing the number of days in the month of this date. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+- {{jsxref("Temporal/ZonedDateTime/daysInWeek", "Temporal.ZonedDateTime.prototype.daysInWeek")}} {{experimental_inline}}
+  - : Returns a positive integer representing the number of days in the week of this date. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. For the ISO 8601 calendar, this is always 7, but in other calendar systems it may differ from week to week.
+- {{jsxref("Temporal/ZonedDateTime/daysInYear", "Temporal.ZonedDateTime.prototype.daysInYear")}} {{experimental_inline}}
+  - : Returns a positive integer representing the number of days in the year of this date. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. For the ISO 8601 calendar, this is 365, or 366 in a leap year.
+- {{jsxref("Temporal/ZonedDateTime/epochMilliseconds", "Temporal.ZonedDateTime.prototype.epochMilliseconds")}} {{experimental_inline}}
+  - : Returns an integer representing the number of milliseconds elapsed since the Unix epoch (midnight at the beginning of January 1, 1970, UTC) to this instant. Equivalent to dividing `epochNanoseconds` by `1e6` and flooring the result.
+- {{jsxref("Temporal/ZonedDateTime/epochNanoseconds", "Temporal.ZonedDateTime.prototype.epochNanoseconds")}} {{experimental_inline}}
+  - : Returns a {{jsxref("BigInt")}} representing the number of nanoseconds elapsed since the Unix epoch (midnight at the beginning of January 1, 1970, UTC) to this instant.
+- {{jsxref("Temporal/ZonedDateTime/era", "Temporal.ZonedDateTime.prototype.era")}} {{experimental_inline}}
+  - : Returns a calendar-specific lowercase string representing the era of this date, or `undefined` if the calendar does not use eras (e.g. ISO 8601). `era` and `eraYear` together uniquely identify a year in a calendar, in the same way that `year` does. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. For Gregorian, it is either `"gregory"` or `"gregory-inverse"`.
+- {{jsxref("Temporal/ZonedDateTime/eraYear", "Temporal.ZonedDateTime.prototype.eraYear")}} {{experimental_inline}}
+  - : Returns a non-negative integer representing the year of this date within the era, or `undefined` if the calendar does not use eras (e.g. ISO 8601). The year index usually starts from 1 (more common) or 0, and years in an era can decrease with time (e.g. Gregorian BCE). `era` and `eraYear` together uniquely identify a year in a calendar, in the same way that `year` does. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+- {{jsxref("Temporal/ZonedDateTime/hour", "Temporal.ZonedDateTime.prototype.hour")}} {{experimental_inline}}
+  - : Returns a integer from 0 to 23 representing the hour component of this time.
+- {{jsxref("Temporal/ZonedDateTime/hoursInDay", "Temporal.ZonedDateTime.prototype.hoursInDay")}} {{experimental_inline}}
+  - : Returns a positive integer representing the number of hours in the day of this date in the time zone. It may be more or less than 24 in the case of offset changes such as daylight saving time.
+- {{jsxref("Temporal/ZonedDateTime/inLeapYear", "Temporal.ZonedDateTime.prototype.inLeapYear")}} {{experimental_inline}}
+  - : Returns a boolean indicating whether this date is in a leap year. A leap year is a year that has more days (due to a leap day or leap month) than a common year. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+- {{jsxref("Temporal/ZonedDateTime/microsecond", "Temporal.ZonedDateTime.prototype.microsecond")}} {{experimental_inline}}
+  - : Returns a integer from 0 to 999 representing the microsecond (10<sup>-6</sup> second) component of this time.
+- {{jsxref("Temporal/ZonedDateTime/millisecond", "Temporal.ZonedDateTime.prototype.millisecond")}} {{experimental_inline}}
+  - : Returns a integer from 0 to 999 representing the millisecond (10<sup>-3</sup> second) component of this time.
+- {{jsxref("Temporal/ZonedDateTime/minute", "Temporal.ZonedDateTime.prototype.minute")}} {{experimental_inline}}
+  - : Returns a integer from 0 to 59 representing the minute component of this time.
+- {{jsxref("Temporal/ZonedDateTime/month", "Temporal.ZonedDateTime.prototype.month")}} {{experimental_inline}}
+  - : Returns a positive integer representing the 1-based month index in the year of this date. The first month of this year is `1`, and the last month is the {{jsxref("Temporal/ZonedDateTime/monthsInYear", "monthsInYear")}}. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. Note that unlike {{jsxref("Date.prototype.getMonth()")}}, the index is 1-based. If the calendar has leap months, then the month with the same {{jsxref("Temporal/ZonedDateTime/monthCode", "monthCode")}} may have different `month` indexes for different years.
+- {{jsxref("Temporal/ZonedDateTime/monthCode", "Temporal.ZonedDateTime.prototype.monthCode")}} {{experimental_inline}}
+  - : Returns a calendar-specific string representing the month of this date. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. Usually it is `M` plus a two-digit month number. For leap months, it is the previous month's code followed by `L`. If the leap month is the first month of the year, the code is `M00L`.
+- {{jsxref("Temporal/ZonedDateTime/monthsInYear", "Temporal.ZonedDateTime.prototype.monthsInYear")}} {{experimental_inline}}
+  - : Returns a positive integer representing the number of months in the year of this date. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. For the ISO 8601 calendar, this is always 12, but in other calendar systems it may differ.
+- {{jsxref("Temporal/ZonedDateTime/nanosecond", "Temporal.ZonedDateTime.prototype.nanosecond")}} {{experimental_inline}}
+  - : Returns a integer from 0 to 999 representing the nanosecond (10<sup>-9</sup> second) component of this time.
+- {{jsxref("Temporal/ZonedDateTime/offset", "Temporal.ZonedDateTime.prototype.offset")}} {{experimental_inline}}
+  - : Returns a string representing the [offset](#time_zones_and_offsets) used to interpret the internal instant, in the form `±HH:mm` (or `±HH:mm:ss.sssssssss` with as much subminute precision as necessary).
+- {{jsxref("Temporal/ZonedDateTime/offsetNanoseconds", "Temporal.ZonedDateTime.prototype.offsetNanoseconds")}} {{experimental_inline}}
+  - : Returns an integer representing the [offset](#time_zones_and_offsets) used to interpret the internal instant, as a number of nanoseconds (positive or negative).
+- {{jsxref("Temporal/ZonedDateTime/second", "Temporal.ZonedDateTime.prototype.second")}} {{experimental_inline}}
+  - : Returns a integer from 0 to 59 representing the second component of this time.
+- {{jsxref("Temporal/ZonedDateTime/timeZoneId", "Temporal.ZonedDateTime.prototype.timeZoneId")}} {{experimental_inline}}
+  - : Returns a string representing the [time zone identifier](#time_zones_and_offsets) used to interpret the internal instant. It uses the same string used when constructing the `Temporal.ZonedDateTime` object, which is either an IANA time zone name or a fixed offset.
+- {{jsxref("Temporal/ZonedDateTime/weekOfYear", "Temporal.ZonedDateTime.prototype.weekOfYear")}} {{experimental_inline}}
+  - : Returns a positive integer representing the 1-based week index in the {{jsxref("Temporal/ZonedDateTime/yearOfWeek", "yearOfWeek")}} of this date, or `undefined` if the calendar does not have a well-defined week system. The first week of the year is `1`. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. Note that for ISO 8601, the first and last few days of the year may be attributed to the last week of the previous year or the first week of the next year.
+- {{jsxref("Temporal/ZonedDateTime/year", "Temporal.ZonedDateTime.prototype.year")}} {{experimental_inline}}
+  - : Returns an integer representing the number of years of this date relative to the start of a calendar-specific epoch year. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. Usually year 1 is either the first year of the latest era or the ISO 8601 year `0001`. If the epoch is in the middle of the year, that year will have the same value before and after the start date of the era.
+- {{jsxref("Temporal/ZonedDateTime/yearOfWeek", "Temporal.ZonedDateTime.prototype.yearOfWeek")}} {{experimental_inline}}
+  - : Returns an integer representing the year to be paired with the {{jsxref("Temporal/ZonedDateTime/weekOfYear", "weekOfYear")}} of this date, or `undefined` if the calendar does not have a well-defined week system. [Calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent. Usually this is the year of the date, but for ISO 8601, the first and last few days of the year may be attributed to the last week of the previous year or the first week of the next year, causing the `yearOfWeek` to differ by 1.
+- `Temporal.ZonedDateTime.prototype[Symbol.toStringTag]`
+  - : The initial value of the [`[Symbol.toStringTag]`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol/toStringTag) property is the string `"Temporal.ZonedDateTime"`. This property is used in {{jsxref("Object.prototype.toString()")}}.
+
+## Instance methods
+
+- {{jsxref("Temporal/ZonedDateTime/add", "Temporal.ZonedDateTime.prototype.add()")}} {{experimental_inline}}
+  - : Returns a new `Temporal.ZonedDateTime` object representing this date-time moved forward by a given duration (in a form convertible by {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}).
+- {{jsxref("Temporal/ZonedDateTime/equals", "Temporal.ZonedDateTime.prototype.equals()")}} {{experimental_inline}}
+  - : Returns `true` if this date-time is equivalent in value to another date-time (in a form convertible by {{jsxref("Temporal/ZonedDateTime/from", "Temporal.ZonedDateTime.from()")}}), and `false` otherwise. They are compared both by their instant values, time zones, and their calendars, so two date-times from different calendars or time zones may be considered equal by {{jsxref("Temporal/ZonedDateTime/compare", "Temporal.ZonedDateTime.compare()")}} but not by `equals()`.
+- {{jsxref("Temporal/ZonedDateTime/getTimeZoneTransition", "Temporal.ZonedDateTime.prototype.getTimeZoneTransition()")}} {{experimental_inline}}
+  - : Returns a `Temporal.ZonedDateTime` object representing the first instant after or before this instant at which the time zone's UTC offset changes, or `null` if there is no such transition. This is useful for finding out the offset rules of a time zone, such as its daylight saving time pattern.
+- {{jsxref("Temporal/ZonedDateTime/round", "Temporal.ZonedDateTime.prototype.round()")}} {{experimental_inline}}
+  - : Returns a new `Temporal.ZonedDateTime` object representing this date-time rounded to the given unit.
+- {{jsxref("Temporal/ZonedDateTime/since", "Temporal.ZonedDateTime.prototype.since()")}} {{experimental_inline}}
+  - : Returns a new {{jsxref("Temporal.Duration")}} object representing the duration from another date-time (in a form convertible by {{jsxref("Temporal/ZonedDateTime/from", "Temporal.ZonedDateTime.from()")}}) to this date-time. The duration is positive if the other date-time is before this date-time, and negative if after.
+- {{jsxref("Temporal/ZonedDateTime/startOfDay", "Temporal.ZonedDateTime.prototype.startOfDay()")}} {{experimental_inline}}
+  - : Returns a `Temporal.ZonedDateTime` object representing the first instant of this date in the time zone. It usually has a time of `00:00:00`, but may be different if the midnight doesn't exist due to offset changes, in which case the first time that exists is returned.
+- {{jsxref("Temporal/ZonedDateTime/subtract", "Temporal.ZonedDateTime.prototype.subtract()")}} {{experimental_inline}}
+  - : Returns a new `Temporal.ZonedDateTime` object representing this date-time moved backward by a given duration (in a form convertible by {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}).
+- {{jsxref("Temporal/ZonedDateTime/toInstant", "Temporal.ZonedDateTime.prototype.toInstant()")}} {{experimental_inline}}
+  - : Returns a new {{jsxref("Temporal.Instant")}} object representing the instant of this date-time.
+- {{jsxref("Temporal/ZonedDateTime/toJSON", "Temporal.ZonedDateTime.prototype.toJSON()")}} {{experimental_inline}}
+  - : Returns a string representing this date-time in the same [RFC 9557 format](#rfc_9557_format) as calling {{jsxref("Temporal/ZonedDateTime/toString", "toString()")}}. Intended to be implicitly called by {{jsxref("JSON.stringify()")}}.
+- {{jsxref("Temporal/ZonedDateTime/toLocaleString", "Temporal.ZonedDateTime.prototype.toLocaleString()")}} {{experimental_inline}}
+  - : Returns a string with a language-sensitive representation of this date-time.
+- {{jsxref("Temporal/ZonedDateTime/toPlainDate", "Temporal.ZonedDateTime.prototype.toPlainDate()")}} {{experimental_inline}}
+  - : Returns a new {{jsxref("Temporal.PlainDate")}} object representing the date portion of this date-time.
+- {{jsxref("Temporal/ZonedDateTime/toPlainDateTime", "Temporal.ZonedDateTime.prototype.toPlainDateTime()")}} {{experimental_inline}}
+  - : Returns a new {{jsxref("Temporal.PlainDateTime")}} object representing the date and time portions of this date-time. Only the time zone information is removed.
+- {{jsxref("Temporal/ZonedDateTime/toPlainTime", "Temporal.ZonedDateTime.prototype.toPlainTime()")}} {{experimental_inline}}
+  - : Returns a new {{jsxref("Temporal.PlainTime")}} object representing the time portion of this date-time.
+- {{jsxref("Temporal/ZonedDateTime/toString", "Temporal.ZonedDateTime.prototype.toString()")}} {{experimental_inline}}
+  - : Returns a string representing this date-time in the [RFC 9557 format](#rfc_9557_format).
+- {{jsxref("Temporal/ZonedDateTime/until", "Temporal.ZonedDateTime.prototype.until()")}} {{experimental_inline}}
+  - : Returns a new {{jsxref("Temporal.Duration")}} object representing the duration from this date-time to another date-time (in a form convertible by {{jsxref("Temporal/ZonedDateTime/from", "Temporal.ZonedDateTime.from()")}}). The duration is positive if the other date-time is after this date-time, and negative if before.
+- {{jsxref("Temporal/ZonedDateTime/valueOf", "Temporal.ZonedDateTime.prototype.valueOf()")}} {{experimental_inline}}
+  - : Throws a {{jsxref("TypeError")}}, which prevents `Temporal.ZonedDateTime` instances from being [implicitly converted to primitives](/en-US/docs/Web/JavaScript/Data_structures#primitive_coercion) when used in arithmetic or comparison operations.
+- {{jsxref("Temporal/ZonedDateTime/with", "Temporal.ZonedDateTime.prototype.with()")}} {{experimental_inline}}
+  - : Returns a new `Temporal.ZonedDateTime` object representing this date-time with some fields replaced by new values.
+- {{jsxref("Temporal/ZonedDateTime/withCalendar", "Temporal.ZonedDateTime.prototype.withCalendar()")}} {{experimental_inline}}
+  - : Returns a new `Temporal.ZonedDateTime` object representing this date-time interpreted in the new calendar system.
+- {{jsxref("Temporal/ZonedDateTime/withPlainTime", "Temporal.ZonedDateTime.prototype.withPlainTime()")}} {{experimental_inline}}
+  - : Returns a new `Temporal.ZonedDateTime` object representing this date-time with the time part entirely replaced by the new time (in a form convertible by {{jsxref("Temporal/PlainTime/from", "Temporal.PlainTime.from()")}})
+- {{jsxref("Temporal/ZonedDateTime/withTimeZone", "Temporal.ZonedDateTime.prototype.withTimeZone()")}} {{experimental_inline}}
+  - : Returns a new `Temporal.ZonedDateTime` object representing the same instant as this date-time but in the new time zone.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal")}}
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal.Instant")}}
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal.PlainTime")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/inleapyear/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/inleapyear/index.md
new file mode 100644
index 000000000000000..6ba0e5951dd7a28
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/inleapyear/index.md
@@ -0,0 +1,46 @@
+---
+title: Temporal.ZonedDateTime.prototype.inLeapYear
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/inLeapYear
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.inLeapYear
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`inLeapYear`** accessor property of {{jsxref("Temporal.ZonedDateTime")}} instances returns a boolean indicating whether this date is in a leap year. A leap year is a year that has more days (due to a leap day or leap month) than a common year. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+The set accessor of `inLeapYear` is `undefined`. You cannot change this property directly.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/inLeapYear", "Temporal.PlainDate.prototype.inLeapYear")}}.
+
+## Examples
+
+### Using inLeapYear
+
+```js
+const dt = Temporal.ZonedDateTime.from("2021-07-01[America/New_York]");
+console.log(dt.inLeapYear); // false
+console.log(dt.daysInYear); // 365
+console.log(dt.monthsInYear); // 12
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/with", "Temporal.ZonedDateTime.prototype.with()")}}
+- {{jsxref("Temporal/ZonedDateTime/add", "Temporal.ZonedDateTime.prototype.add()")}}
+- {{jsxref("Temporal/ZonedDateTime/subtract", "Temporal.ZonedDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/ZonedDateTime/year", "Temporal.ZonedDateTime.prototype.year")}}
+- {{jsxref("Temporal/ZonedDateTime/daysInYear", "Temporal.ZonedDateTime.prototype.daysInYear")}}
+- {{jsxref("Temporal/ZonedDateTime/monthsInYear", "Temporal.ZonedDateTime.prototype.monthsInYear")}}
+- {{jsxref("Temporal/PlainDate/inLeapYear", "Temporal.PlainDate.prototype.inLeapYear")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/microsecond/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/microsecond/index.md
new file mode 100644
index 000000000000000..3231a40a40c90b5
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/microsecond/index.md
@@ -0,0 +1,46 @@
+---
+title: Temporal.ZonedDateTime.prototype.microsecond
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/microsecond
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.microsecond
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`microsecond`** accessor property of {{jsxref("Temporal.ZonedDateTime")}} instances returns a integer from 0 to 999 representing the microsecond (10<sup>-6</sup> second) component of this time.
+
+The set accessor of `microsecond` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/ZonedDateTime/with", "with()")}} method to create a new `Temporal.ZonedDateTime` object with the desired new value.
+
+For general information and more examples, see {{jsxref("Temporal/PlainTime/microsecond", "Temporal.PlainTime.prototype.microsecond")}}.
+
+## Examples
+
+### Using microsecond
+
+```js
+const dt = Temporal.ZonedDateTime.from(
+  "2021-07-01T12:34:56.123456789-04:00[America/New_York]",
+);
+console.log(dt.microsecond); // 456
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/with", "Temporal.ZonedDateTime.prototype.with()")}}
+- {{jsxref("Temporal/ZonedDateTime/add", "Temporal.ZonedDateTime.prototype.add()")}}
+- {{jsxref("Temporal/ZonedDateTime/subtract", "Temporal.ZonedDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/ZonedDateTime/second", "Temporal.ZonedDateTime.prototype.second")}}
+- {{jsxref("Temporal/ZonedDateTime/millisecond", "Temporal.ZonedDateTime.prototype.millisecond")}}
+- {{jsxref("Temporal/ZonedDateTime/nanosecond", "Temporal.ZonedDateTime.prototype.nanosecond")}}
+- {{jsxref("Temporal/PlainTime/microsecond", "Temporal.PlainTime.prototype.microsecond")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/millisecond/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/millisecond/index.md
new file mode 100644
index 000000000000000..789b3e65e9aa5f2
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/millisecond/index.md
@@ -0,0 +1,46 @@
+---
+title: Temporal.ZonedDateTime.prototype.millisecond
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/millisecond
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.millisecond
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`millisecond`** accessor property of {{jsxref("Temporal.ZonedDateTime")}} instances returns a integer from 0 to 999 representing the millisecond (10<sup>-3</sup> second) component of this time.
+
+The set accessor of `millisecond` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/ZonedDateTime/with", "with()")}} method to create a new `Temporal.ZonedDateTime` object with the desired new value.
+
+For general information and more examples, see {{jsxref("Temporal/PlainTime/millisecond", "Temporal.PlainTime.prototype.millisecond")}}.
+
+## Examples
+
+### Using millisecond
+
+```js
+const dt = Temporal.ZonedDateTime.from(
+  "2021-07-01T12:34:56.123456789-04:00[America/New_York]",
+);
+console.log(dt.millisecond); // 123
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/with", "Temporal.ZonedDateTime.prototype.with()")}}
+- {{jsxref("Temporal/ZonedDateTime/add", "Temporal.ZonedDateTime.prototype.add()")}}
+- {{jsxref("Temporal/ZonedDateTime/subtract", "Temporal.ZonedDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/ZonedDateTime/second", "Temporal.ZonedDateTime.prototype.second")}}
+- {{jsxref("Temporal/ZonedDateTime/microsecond", "Temporal.ZonedDateTime.prototype.microsecond")}}
+- {{jsxref("Temporal/ZonedDateTime/nanosecond", "Temporal.ZonedDateTime.prototype.nanosecond")}}
+- {{jsxref("Temporal/PlainTime/millisecond", "Temporal.PlainTime.prototype.millisecond")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/minute/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/minute/index.md
new file mode 100644
index 000000000000000..764c92237c779fc
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/minute/index.md
@@ -0,0 +1,73 @@
+---
+title: Temporal.ZonedDateTime.prototype.minute
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/minute
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.minute
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`minute`** accessor property of {{jsxref("Temporal.ZonedDateTime")}} instances returns a integer from 0 to 59 representing the minute component of this time.
+
+The set accessor of `minute` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/ZonedDateTime/with", "with()")}} method to create a new `Temporal.ZonedDateTime` object with the desired new value.
+
+For general information and more examples, see {{jsxref("Temporal/PlainTime/minute", "Temporal.PlainTime.prototype.minute")}}.
+
+For `ZonedDateTime`, `minute` can be non-continuous due to offset changes. While much rarer than `hour` changes (because daylight saving time shifts are usually by whole hours), it can still happen.
+
+## Examples
+
+### Using minute
+
+```js
+const dt = Temporal.ZonedDateTime.from(
+  "2021-07-01T12:34:56.123456789-04:00[America/New_York]",
+);
+console.log(dt.minute); // 34
+```
+
+### Non-continuous minute
+
+Typically, `minute` always goes from 0 to 59 and then back to 0, even when passing through a daylight saving time transition. There's one particular case where DST has a 30-minute offset: Lord Howe Island in Australia, which shifts between +10:30 and +11:00. In this case, the minute can be non-continuous.
+
+```js
+const dt = Temporal.ZonedDateTime.from(
+  "2021-10-03T01:59:00+10:30[Australia/Lord_Howe]",
+);
+console.log(dt.minute); // 59
+const dt2 = dt.add({ minutes: 1 });
+console.log(dt2.minute); // 30
+console.log(dt2.toString()); // 2021-10-03T02:30:00+11:00[Australia/Lord_Howe]
+```
+
+There's a second peculiar case where the minute can be non-continuous: the standardization of hourly time zones. In the early 20th century, most countries were using their own time zones which were often not a whole hour offset from UTC. For example, Paris used to have an offset of UTC+0:09:21, which was changed to UTC+0 on March 11, 1911.
+
+```js
+const dt = Temporal.ZonedDateTime.from(
+  "1911-03-10T23:59:00+00:09:21[Europe/Paris]",
+);
+console.log(dt.minute); // 59
+const dt2 = dt.add({ minutes: 1 });
+console.log(dt2.minute); // 50
+console.log(dt2.toString()); // 1911-03-10T23:50:39+00:00[Europe/Paris]
+```
+
+For this reason, you should always prefer {{jsxref("Temporal/ZonedDateTime/add", "add()")}} and {{jsxref("Temporal/ZonedDateTime/subtract", "subtract()")}} to manipulate dates and times, rather than directly changing the `minute` property.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/with", "Temporal.ZonedDateTime.prototype.with()")}}
+- {{jsxref("Temporal/ZonedDateTime/add", "Temporal.ZonedDateTime.prototype.add()")}}
+- {{jsxref("Temporal/ZonedDateTime/subtract", "Temporal.ZonedDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/PlainTime/minute", "Temporal.ZonedDateTime.prototype.minute")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/month/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/month/index.md
new file mode 100644
index 000000000000000..532fb236def8586
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/month/index.md
@@ -0,0 +1,47 @@
+---
+title: Temporal.ZonedDateTime.prototype.month
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/month
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.month
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`month`** accessor property of {{jsxref("Temporal.ZonedDateTime")}} instances returns a positive integer representing the 1-based month index in the year of this date. The first month of this year is `1`, and the last month is the {{jsxref("Temporal/ZonedDateTime/monthsInYear", "monthsInYear")}}. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+The set accessor of `month` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/ZonedDateTime/with", "with()")}} method to create a new `Temporal.ZonedDateTime` object with the desired new value.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/month", "Temporal.PlainDate.prototype.month")}}.
+
+## Examples
+
+### Using month
+
+```js
+const dt = Temporal.ZonedDateTime.from("2021-07-01[America/New_York]"); // ISO 8601 calendar
+console.log(dt.monthCode); // "M07"
+console.log(dt.month); // 7
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/with", "Temporal.ZonedDateTime.prototype.with()")}}
+- {{jsxref("Temporal/ZonedDateTime/add", "Temporal.ZonedDateTime.prototype.add()")}}
+- {{jsxref("Temporal/ZonedDateTime/subtract", "Temporal.ZonedDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/ZonedDateTime/year", "Temporal.ZonedDateTime.prototype.year")}}
+- {{jsxref("Temporal/ZonedDateTime/day", "Temporal.ZonedDateTime.prototype.day")}}
+- {{jsxref("Temporal/ZonedDateTime/monthCode", "Temporal.ZonedDateTime.prototype.monthCode")}}
+- {{jsxref("Temporal/ZonedDateTime/daysInMonth", "Temporal.ZonedDateTime.prototype.daysInMonth")}}
+- {{jsxref("Temporal/ZonedDateTime/monthsInYear", "Temporal.ZonedDateTime.prototype.monthsInYear")}}
+- {{jsxref("Temporal/PlainDate/month", "Temporal.PlainDate.prototype.month")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/monthcode/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/monthcode/index.md
new file mode 100644
index 000000000000000..e400dfba185defa
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/monthcode/index.md
@@ -0,0 +1,48 @@
+---
+title: Temporal.ZonedDateTime.prototype.monthCode
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/monthCode
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.monthCode
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`monthCode`** accessor property of {{jsxref("Temporal.ZonedDateTime")}} instances returns a calendar-specific string representing the month of this date. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+Usually it is `M` plus a two-digit month number. For leap months, it is the previous month's code followed by `L` (even if it's conceptually a derivative of the following month; for example, in the Hebrew calendar, Adar I has code `M05L` but Adar II has code `M06`). If the leap month is the first month of the year, the code is `M00L`.
+
+The set accessor of `monthCode` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/ZonedDateTime/with", "with()")}} method to create a new `Temporal.ZonedDateTime` object with the desired new value.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/monthCode", "Temporal.PlainDate.prototype.monthCode")}}.
+
+## Examples
+
+### Using monthCode
+
+```js
+const date = Temporal.ZonedDateTime.from("2021-07-01[America/New_York]"); // ISO 8601 calendar
+console.log(date.monthCode); // "M07"
+console.log(date.month); // 7
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/with", "Temporal.ZonedDateTime.prototype.with()")}}
+- {{jsxref("Temporal/ZonedDateTime/add", "Temporal.ZonedDateTime.prototype.add()")}}
+- {{jsxref("Temporal/ZonedDateTime/subtract", "Temporal.ZonedDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/ZonedDateTime/year", "Temporal.ZonedDateTime.prototype.year")}}
+- {{jsxref("Temporal/ZonedDateTime/month", "Temporal.ZonedDateTime.prototype.month")}}
+- {{jsxref("Temporal/ZonedDateTime/daysInMonth", "Temporal.ZonedDateTime.prototype.daysInMonth")}}
+- {{jsxref("Temporal/ZonedDateTime/monthsInYear", "Temporal.ZonedDateTime.prototype.monthsInYear")}}
+- {{jsxref("Temporal/PlainDate/monthCode", "Temporal.PlainDate.prototype.monthCode")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/monthsinyear/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/monthsinyear/index.md
new file mode 100644
index 000000000000000..625dce74eb151e5
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/monthsinyear/index.md
@@ -0,0 +1,45 @@
+---
+title: Temporal.ZonedDateTime.prototype.monthsInYear
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/monthsInYear
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.monthsInYear
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`monthsInYear`** accessor property of {{jsxref("Temporal.ZonedDateTime")}} instances returns a positive integer representing the number of months in the year of this date. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+The set accessor of `monthsInYear` is `undefined`. You cannot change this property directly.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/monthsInYear", "Temporal.PlainDate.prototype.monthsInYear")}}.
+
+## Examples
+
+### Using monthsInYear
+
+```js
+const dt = Temporal.ZonedDateTime.from("2021-07-01[America/New_York]");
+console.log(dt.monthsInYear); // 12
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/with", "Temporal.ZonedDateTime.prototype.with()")}}
+- {{jsxref("Temporal/ZonedDateTime/add", "Temporal.ZonedDateTime.prototype.add()")}}
+- {{jsxref("Temporal/ZonedDateTime/subtract", "Temporal.ZonedDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/ZonedDateTime/year", "Temporal.ZonedDateTime.prototype.year")}}
+- {{jsxref("Temporal/ZonedDateTime/month", "Temporal.ZonedDateTime.prototype.month")}}
+- {{jsxref("Temporal/ZonedDateTime/monthCode", "Temporal.ZonedDateTime.prototype.monthCode")}}
+- {{jsxref("Temporal/ZonedDateTime/daysInMonth", "Temporal.ZonedDateTime.prototype.daysInMonth")}}
+- {{jsxref("Temporal/PlainDate/monthsInYear", "Temporal.PlainDate.prototype.monthsInYear")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/nanosecond/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/nanosecond/index.md
new file mode 100644
index 000000000000000..3149f233fda8739
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/nanosecond/index.md
@@ -0,0 +1,46 @@
+---
+title: Temporal.ZonedDateTime.prototype.nanosecond
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/nanosecond
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.nanosecond
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`nanosecond`** accessor property of {{jsxref("Temporal.ZonedDateTime")}} instances returns a integer from 0 to 999 representing the nanosecond (10<sup>-9</sup> second) component of this time.
+
+The set accessor of `nanosecond` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/ZonedDateTime/with", "with()")}} method to create a new `Temporal.ZonedDateTime` object with the desired new value.
+
+For general information and more examples, see {{jsxref("Temporal/PlainTime/nanosecond", "Temporal.PlainTime.prototype.nanosecond")}}.
+
+## Examples
+
+### Using nanosecond
+
+```js
+const dt = Temporal.ZonedDateTime.from(
+  "2021-07-01T12:34:56.123456789-04:00[America/New_York]",
+);
+console.log(dt.nanosecond); // 789
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/with", "Temporal.ZonedDateTime.prototype.with()")}}
+- {{jsxref("Temporal/ZonedDateTime/add", "Temporal.ZonedDateTime.prototype.add()")}}
+- {{jsxref("Temporal/ZonedDateTime/subtract", "Temporal.ZonedDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/ZonedDateTime/second", "Temporal.ZonedDateTime.prototype.second")}}
+- {{jsxref("Temporal/ZonedDateTime/millisecond", "Temporal.ZonedDateTime.prototype.millisecond")}}
+- {{jsxref("Temporal/ZonedDateTime/microsecond", "Temporal.ZonedDateTime.prototype.microsecond")}}
+- {{jsxref("Temporal/PlainTime/nanosecond", "Temporal.PlainTime.prototype.nanosecond")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/offset/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/offset/index.md
new file mode 100644
index 000000000000000..7d7726eebf6b688
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/offset/index.md
@@ -0,0 +1,64 @@
+---
+title: Temporal.ZonedDateTime.prototype.offset
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/offset
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.offset
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`offset`** accessor property of {{jsxref("Temporal.ZonedDateTime")}} instances returns a string representing the [offset](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#time_zones_and_offsets) used to interpret the internal instant, in the form `±HH:mm` (or `±HH:mm:ss.sssssssss` with as much subminute precision as necessary). This offset is guaranteed to be valid for the given instant and time zone at construction time.
+
+The set accessor of `offset` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/ZonedDateTime/with", "with()")}} method to create a new `Temporal.ZonedDateTime` object with the desired new value (usually also changing the date/time), or use the {{jsxref("Temporal/ZonedDateTime/withTimeZone", "withTimeZone()")}} method to create a new `Temporal.ZonedDateTime` object in another time zone.
+
+## Examples
+
+### Using offset
+
+```js
+const dt = Temporal.ZonedDateTime.from(
+  "2021-07-01T12:00:00-07:00[America/Los_Angeles]",
+);
+console.log(dt.offset); // "-07:00"
+
+const dt2 = Temporal.ZonedDateTime.from("2021-07-01T12:00:00-07[-07]");
+console.log(dt2.offset); // "-07:00"
+
+const dt3 = Temporal.ZonedDateTime.from(
+  "1900-01-01T00:00:00+00:09:21[Europe/Paris]",
+);
+console.log(dt3.offset); // "+00:09:21"
+
+const dt4 = Temporal.ZonedDateTime.from("2021-07-01T12:00:00Z[Asia/Shanghai]");
+console.log(dt4.offset); // "+08:00"
+```
+
+### Changing offset
+
+If the local time happens to have two valid offsets, such as within a DST transition, you can change the offset without changing anything else:
+
+```js
+const zdt = Temporal.ZonedDateTime.from(
+  "2024-11-03T01:05:00-04:00[America/New_York]",
+);
+const newZDT = zdt.with({ offset: "-05:00" });
+console.log(newZDT.toString()); // "2024-11-03T01:05:00-05:00[America/New_York]"
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/with", "Temporal.ZonedDateTime.prototype.with()")}}
+- {{jsxref("Temporal/ZonedDateTime/withTimeZone", "Temporal.ZonedDateTime.prototype.withTimeZone()")}}
+- {{jsxref("Temporal/ZonedDateTime/timeZoneId", "Temporal.ZonedDateTime.prototype.timeZoneId")}}
+- {{jsxref("Temporal/ZonedDateTime/offsetNanoseconds", "Temporal.ZonedDateTime.prototype.offsetNanoseconds")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/offsetnanoseconds/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/offsetnanoseconds/index.md
new file mode 100644
index 000000000000000..235c98aac3786bf
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/offsetnanoseconds/index.md
@@ -0,0 +1,71 @@
+---
+title: Temporal.ZonedDateTime.prototype.offsetNanoseconds
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/offsetNanoseconds
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.offsetNanoseconds
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`offsetNanoseconds`** accessor property of {{jsxref("Temporal.ZonedDateTime")}} instances returns an integer representing the [offset](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#time_zones_and_offsets) used to interpret the internal instant, as a number of nanoseconds (positive or negative). The value is a safe integer because it's less than a day, which is 8.64e15 nanoseconds.
+
+The set accessor of `offsetNanoseconds` is `undefined`. You cannot change this property directly. Change {{jsxref("Temporal/ZonedDateTime/offset", "offset")}} to change this property too.
+
+## Examples
+
+### Using offsetNanoseconds
+
+```js
+const dt = Temporal.ZonedDateTime.from(
+  "2021-07-01T12:00:00-07:00[America/Los_Angeles]",
+);
+console.log(dt.offsetNanoseconds); // -25200000000000
+
+const dt2 = Temporal.ZonedDateTime.from(
+  "2021-07-01T12:00:00+08:00[Asia/Shanghai]",
+);
+console.log(dt2.offsetNanoseconds); // 28800000000000
+
+const dt3 = Temporal.ZonedDateTime.from(
+  "1900-01-01T00:00:00+00:09:21[Europe/Paris]",
+);
+console.log(dt3.offsetNanoseconds); // 561000000000
+```
+
+Here's one way to get a `ZonedDateTime` representing the same wall-clock time in UTC:
+
+```js
+const dt = Temporal.ZonedDateTime.from(
+  "2021-07-01T12:00:00-07:00[America/Los_Angeles]",
+);
+const dtInUTC = dt.add({ nanoseconds: dt.offsetNanoseconds });
+console.log(dtInUTC.withTimeZone("UTC").toString()); // "2021-07-01T12:00:00+00:00[UTC]"
+```
+
+Here's a better way to get the same result:
+
+```js
+const dt = Temporal.ZonedDateTime.from(
+  "2021-07-01T12:00:00-07:00[America/Los_Angeles]",
+);
+const dtInUTC = dt.toPlainDateTime().toZonedDateTime("UTC");
+console.log(dtInUTC.toString()); // "2021-07-01T12:00:00+00:00[UTC]"
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/with", "Temporal.ZonedDateTime.prototype.with()")}}
+- {{jsxref("Temporal/ZonedDateTime/withTimeZone", "Temporal.ZonedDateTime.prototype.withTimeZone()")}}
+- {{jsxref("Temporal/ZonedDateTime/offset", "Temporal.ZonedDateTime.prototype.offset")}}
+- {{jsxref("Temporal/ZonedDateTime/timeZoneId", "Temporal.ZonedDateTime.prototype.timeZoneId")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/round/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/round/index.md
new file mode 100644
index 000000000000000..4edc79315d555b0
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/round/index.md
@@ -0,0 +1,91 @@
+---
+title: Temporal.ZonedDateTime.prototype.round()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/round
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.round
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`round()`** method of {{jsxref("Temporal.ZonedDateTime")}} instances returns a new `Temporal.ZonedDateTime` object representing this date-time rounded to the given unit.
+
+## Syntax
+
+```js-nolint
+round(smallestUnit)
+round(options)
+```
+
+### Parameters
+
+- `smallestUnit`
+  - : A string representing the [`smallestUnit`](#smallestunit_2) option. This is a convenience overload, so `round(smallestUnit)` is equivalent to `round({ smallestUnit })`, where `smallestUnit` is a string.
+- `options`
+  - : An object containing some or all of the following properties (in the order they are retrieved and validated):
+    - `roundingIncrement` {{optional_inline}}
+      - : A number (truncated to an integer) representing the rounding increment in the given `smallestUnit`. Defaults to `1`. For all values of `smallestUnit` except `"day"`, the increment must be a divisor of the maximum value of the unit; for example, if the unit is hours, the increment must be a divisor of 24 and must not be 24 itself, which means it can be 1, 2, 3, 4, 6, 8, or 12. For `"day"`, the increment must be 1.
+    - `roundingMode` {{optional_inline}}
+      - : A string specifying how to round off the fractional part of `smallestUnit`. See [`Intl.NumberFormat()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/NumberFormat/NumberFormat#roundingmode). Defaults to `"halfExpand"`.
+    - `smallestUnit`
+      - : A string representing the smallest unit to include in the output. The value must be one of the following: `"day"`, `"hour"`, `"minute"`, `"second"`, `"millisecond"`, `"microsecond"`, `"nanosecond"`, or their plural forms. For units larger than `"nanosecond"`, fractional parts of the `smallestUnit` will be rounded according to the `roundingIncrement` and `roundingMode` settings.
+
+### Return value
+
+A new {{jsxref("Temporal.ZonedDateTime")}} object representing this date-time rounded to the given unit, where all units smaller than `smallestUnit` are zeroed out.
+
+If `smallestUnit` is `"day"`, the returned date-time will be the [start of day](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/startOfDay) of this date or the next day, depending on the `roundingMode` and the distance to these two instants. Otherwise, the rounding is first performed on its `PlainDateTime` (same as {{jsxref("Temporal/PlainDateTime/round", "Temporal.PlainDateTime.prototype.round()")}}), and then re-interpreted in the same time zone, with `disambiguation: "compatible", offset: "prefer"`. See [ambiguity and gaps from local time to UTC time](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#ambiguity_and_gaps_from_local_time_to_utc_time) and [offset ambiguity](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#offset_ambiguity).
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown if any of the options is invalid.
+
+## Examples
+
+### Rounding off small units
+
+```js
+const zdt = Temporal.ZonedDateTime.from(
+  "2021-07-01T12:34:56.123456789[America/New_York]",
+);
+const nearestMillisecond = zdt.round("millisecond");
+console.log(nearestMillisecond.toString()); // 2021-07-01T12:34:56.123-04:00[America/New_York]
+
+const nearestHalfHour = zdt.round({
+  smallestUnit: "minute",
+  roundingIncrement: 30,
+});
+console.log(nearestHalfHour.toString()); // 2021-07-01T12:30:00-04:00[America/New_York]
+
+const nextDay = zdt.round({ smallestUnit: "day", roundingMode: "ceil" });
+console.log(nextDay.toString()); // 2021-07-02T00:00:00-04:00[America/New_York]
+```
+
+### Ambiguity after rounding
+
+It's possible that the rounded date-time is ambiguous in the given time zone. The ambiguity is always resolved using `disambiguation: "compatible", offset: "prefer"`. Here's a quick example:
+
+```js
+const zdt = Temporal.ZonedDateTime.from(
+  "2024-03-10T01:00:00-05:00[America/New_York]",
+);
+const rounded = zdt.round({ smallestUnit: "hour", roundingIncrement: 2 });
+// The result is supposed to be 2024-03-10T02:00:00-05:00[America/New_York],
+// but this time does not exist. `disambiguation: "compatible"` tells us to move
+// forward by 1 hour.
+console.log(rounded.toString()); // 2024-03-10T03:00:00-04:00[America/New_York]
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/second/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/second/index.md
new file mode 100644
index 000000000000000..b61fb3f0f481747
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/second/index.md
@@ -0,0 +1,64 @@
+---
+title: Temporal.ZonedDateTime.prototype.second
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/second
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.second
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`second`** accessor property of {{jsxref("Temporal.ZonedDateTime")}} instances returns a integer from 0 to 59 representing the second component of this time.
+
+The set accessor of `second` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/ZonedDateTime/with", "with()")}} method to create a new `Temporal.ZonedDateTime` object with the desired new value.
+
+For general information and more examples, see {{jsxref("Temporal/PlainTime/second", "Temporal.PlainTime.prototype.second")}}.
+
+For `ZonedDateTime`, `second` can be non-continuous due to offset changes. While much rarer than `hour` or `minute` changes (because daylight saving time shifts are usually by whole hours), it can still happen.
+
+## Examples
+
+### Using second
+
+```js
+const dt = Temporal.ZonedDateTime.from(
+  "2021-07-01T12:34:56.123456789-04:00[America/New_York]",
+);
+console.log(dt.second); // 56
+```
+
+### Non-continuous second
+
+Typically, `second` always goes from 0 to 59 and then back to 0, even when passing through a daylight saving time transition. There's a peculiar case where the second can be non-continuous: the standardization of hourly time zones. In the early 20th century, most countries were using their own time zones which were often not a whole hour offset from UTC. For example, Paris used to have an offset of UTC+0:09:21, which was changed to UTC+0 on March 11, 1911.
+
+```js
+const dt = Temporal.ZonedDateTime.from(
+  "1911-03-10T23:59:59+00:09:21[Europe/Paris]",
+);
+console.log(dt.second); // 59
+const dt2 = dt.add({ seconds: 1 });
+console.log(dt2.second); // 39
+console.log(dt2.toString()); // 1911-03-10T23:50:39+00:00[Europe/Paris]
+```
+
+For this reason, you should always prefer {{jsxref("Temporal/ZonedDateTime/add", "add()")}} and {{jsxref("Temporal/ZonedDateTime/subtract", "subtract()")}} to manipulate dates and times, rather than directly changing the `second` property.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/with", "Temporal.ZonedDateTime.prototype.with()")}}
+- {{jsxref("Temporal/ZonedDateTime/add", "Temporal.ZonedDateTime.prototype.add()")}}
+- {{jsxref("Temporal/ZonedDateTime/subtract", "Temporal.ZonedDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/ZonedDateTime/millisecond", "Temporal.ZonedDateTime.prototype.millisecond")}}
+- {{jsxref("Temporal/ZonedDateTime/microsecond", "Temporal.ZonedDateTime.prototype.microsecond")}}
+- {{jsxref("Temporal/ZonedDateTime/nanosecond", "Temporal.ZonedDateTime.prototype.nanosecond")}}
+- {{jsxref("Temporal/PlainTime/second", "Temporal.PlainTime.prototype.second")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/since/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/since/index.md
new file mode 100644
index 000000000000000..05eed7ada053784
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/since/index.md
@@ -0,0 +1,110 @@
+---
+title: Temporal.ZonedDateTime.prototype.since()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/since
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.since
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`since()`** method of {{jsxref("Temporal.ZonedDateTime")}} instances returns a new {{jsxref("Temporal.Duration")}} object representing the duration from another date-time (in a form convertible by {{jsxref("Temporal/ZonedDateTime/from", "Temporal.ZonedDateTime.from()")}}) to this date-time. The duration is positive if the other date-time is before this date-time, and negative if after.
+
+This method does `this - other`. To do `other - this`, use the {{jsxref("Temporal/ZonedDateTime/until", "until()")}} method.
+
+## Syntax
+
+```js-nolint
+since(other)
+since(other, options)
+```
+
+### Parameters
+
+- `other`
+  - : A string, an object, or a {{jsxref("Temporal.ZonedDateTime")}} instance representing a date-time to subtract from this date-time. It is converted to a `Temporal.ZonedDateTime` object using the same algorithm as {{jsxref("Temporal/ZonedDateTime/from", "Temporal.ZonedDateTime.from()")}}. It must have the same calendar as `this`.
+- `options` {{optional_inline}}
+  - : An object containing the options for {{jsxref("Temporal/Duration/round", "Temporal.Duration.prototype.round()")}}, which includes `largestUnit`, `roundingIncrement`, `roundingMode`, and `smallestUnit`. `largestUnit` and `smallestUnit` accept all possible units. For `largestUnit`, the default value `"auto"` means `"hour"` or `smallestUnit`, whichever is greater. For `smallestUnit`, the default value is `"nanosecond"`. The current date is used as the `relativeTo` option. Note that using [units larger than `"hour"`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Duration#calendar_durations) may make the duration not portable to other calendars, dates, or time zones.
+
+### Return value
+
+A new {{jsxref("Temporal.Duration")}} object representing the duration _since_ `other` to this date-time. The duration is positive if `other` is before this date-time, and negative if after.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown in one of the following cases:
+    - `other` has a different calendar than `this`.
+    - Any of the options is invalid.
+    - `other` has a different time zone than `this`, and `largestUnit` is `"day"` or above.
+
+## Description
+
+The duration returned is a "hybrid" duration. This means that the duration's date portion represents full calendar days like {{jsxref("Temporal/PlainDateTime/since", "Temporal.PlainDateTime.prototype.since()")}} would return, while its time portion represents real-world elapsed time like {{jsxref("Temporal/Instant/since", "Temporal.Instant.prototype.since()")}} would return. This "hybrid duration" approach automatically adjusts for DST and matches widely-adopted industry standards like [RFC 5545 (iCalendar)](https://datatracker.ietf.org/doc/html/rfc5545). See below for examples.
+
+## Examples
+
+### Offset transitions
+
+When transitions happen, a day may not have exactly 24 hours.
+
+```js
+const start = Temporal.ZonedDateTime.from(
+  "2024-11-03T01:00:00-04:00[America/New_York]",
+);
+const end = Temporal.ZonedDateTime.from(
+  "2024-11-04T01:00:00-05:00[America/New_York]",
+);
+console.log(end.since(start).toString()); // PT25H
+console.log(end.since(start, { largestUnit: "day" }).toString()); // PT1D
+
+const start2 = Temporal.ZonedDateTime.from(
+  "2024-03-10T01:00:00-05:00[America/New_York]",
+);
+const end2 = Temporal.ZonedDateTime.from(
+  "2024-03-11T01:00:00-04:00[America/New_York]",
+);
+console.log(end2.since(start2).toString()); // PT23H
+console.log(end2.since(start2, { largestUnit: "day" }).toString()); // PT1D
+```
+
+For this reason, the returned duration is purely time-based with no date portion by default, so that it stays unambiguous.
+
+### Different time zones
+
+The time portion of the returned duration is purely based on instants and is not affected by time zones. However, if you want to include any date units like `day`, then the start and end must be in the same time zone.
+
+```js
+const start = Temporal.ZonedDateTime.from(
+  "2024-11-03T01:00:00-04:00[America/New_York]",
+);
+// Peru does not use DST so its offset remains -05:00 year-round
+const end = Temporal.ZonedDateTime.from(
+  "2024-11-04T01:00:00-05:00[America/Lima]",
+);
+
+end.since(start); // PT25H
+end.since(start, { largestUnit: "day" }); // RangeError: time zones "America/Lima" and "America/New_York" aren't compatible
+
+end.withTimeZone("America/New_York").since(start, { largestUnit: "day" }); // P1D
+end.since(start.withTimeZone("America/Lima"), { largestUnit: "day" }); // P1D1H
+```
+
+For more examples about how to use `since()`, especially with rounding, see {{jsxref("Temporal/PlainDate/since", "Temporal.PlainDate.prototype.since()")}} and {{jsxref("Temporal/PlainTime/since", "Temporal.PlainTime.prototype.since()")}}.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/ZonedDateTime/add", "Temporal.ZonedDateTime.prototype.add()")}}
+- {{jsxref("Temporal/ZonedDateTime/subtract", "Temporal.ZonedDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/ZonedDateTime/until", "Temporal.ZonedDateTime.prototype.until()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/startofday/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/startofday/index.md
new file mode 100644
index 000000000000000..d8ba13eb3c4a115
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/startofday/index.md
@@ -0,0 +1,68 @@
+---
+title: Temporal.ZonedDateTime.prototype.startOfDay()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/startOfDay
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.startOfDay
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`startOfDay()`** method of {{jsxref("Temporal.ZonedDateTime")}} instances returns a {{jsxref("Temporal.ZonedDateTime")}} object representing the first instant of this date in the time zone. It usually has a time of `00:00:00`, but may be different if the midnight doesn't exist due to offset changes, in which case the first time that exists is returned.
+
+It is equivalent to calling {{jsxref("Temporal/ZonedDateTime/withPlainTime", "withPlainTime()")}} with no arguments.
+
+## Syntax
+
+```js-nolint
+startOfDay()
+```
+
+### Parameters
+
+None.
+
+### Return value
+
+A {{jsxref("Temporal.ZonedDateTime")}} object with instant `t`, such that:
+
+- The date at `t` is different from the date one nanosecond before `t`.
+- The date at `t` is the same as the date of `this`.
+
+## Examples
+
+### Using startOfDay()
+
+```js
+// In the US, DST transitions happen at 2am, so the midnight exists
+const dt = Temporal.ZonedDateTime.from(
+  "2024-03-10T12:00:00-04:00[America/New_York]",
+);
+console.log(dt.startOfDay().toString()); // "2024-03-10T00:00:00-05:00[America/New_York]"
+
+// In Brazil, DST transitions happened at midnight, so the midnight didn't exist
+const dt2 = Temporal.ZonedDateTime.from(
+  "2015-10-18T12:00-02:00[America/Sao_Paulo]",
+);
+console.log(dt2.startOfDay().toString()); // "2015-10-18T01:00:00-02:00[America/Sao_Paulo]"
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/with", "Temporal.ZonedDateTime.prototype.with()")}}
+- {{jsxref("Temporal/ZonedDateTime/add", "Temporal.ZonedDateTime.prototype.add()")}}
+- {{jsxref("Temporal/ZonedDateTime/subtract", "Temporal.ZonedDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/ZonedDateTime/hour", "Temporal.ZonedDateTime.prototype.hour")}}
+- {{jsxref("Temporal/ZonedDateTime/hoursInDay", "Temporal.ZonedDateTime.prototype.hoursInDay")}}
+- {{jsxref("Temporal/ZonedDateTime/timeZoneId", "Temporal.ZonedDateTime.prototype.timeZoneId")}}
+- {{jsxref("Temporal/ZonedDateTime/getTimeZoneTransition", "Temporal.ZonedDateTime.prototype.getTimeZoneTransition()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/subtract/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/subtract/index.md
new file mode 100644
index 000000000000000..6c22c5dd9bf0cf6
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/subtract/index.md
@@ -0,0 +1,79 @@
+---
+title: Temporal.ZonedDateTime.prototype.subtract()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/subtract
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.subtract
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`subtract()`** method of {{jsxref("Temporal.ZonedDateTime")}} instances returns a new `Temporal.ZonedDateTime` object representing this date-time moved backward by a given duration (in a form convertible by {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}).
+
+If you want to subtract two date-times and get a duration, use {{jsxref("Temporal/ZonedDateTime/since", "since()")}} or {{jsxref("Temporal/ZonedDateTime/until", "until()")}} instead.
+
+## Syntax
+
+```js-nolint
+subtract(duration)
+subtract(duration, options)
+```
+
+### Parameters
+
+- `duration`
+  - : A string, an object, or a {{jsxref("Temporal.Duration")}} instance representing a duration to subtract from this date-time. It is converted to a `Temporal.Duration` object using the same algorithm as {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}.
+- `options` {{optional_inline}}
+  - : An object containing the following property:
+    - `overflow` {{optional_inline}}
+      - : A string specifying the behavior when a date component is out of range. Possible values are:
+        - `"constrain"` (default)
+          - : The date component is [clamped](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate#invalid_date_clamping) to the valid range.
+        - `"reject"`
+          - : A {{jsxref("RangeError")}} is thrown if the date component is out of range.
+
+### Return value
+
+A new `Temporal.ZonedDateTime` object representing the date-time specified by the original `ZonedDateTime`, minus the duration.
+
+## Description
+
+Subtracting a duration is equivalent to [adding](Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/add) its [negation](Web/JavaScript/Reference/Global_Objects/Temporal/Duration/negated), so all the same considerations apply.
+
+## Examples
+
+### Subtracting a duration
+
+```js
+const start = Temporal.ZonedDateTime.from(
+  "2021-01-01T12:34:56-05:00[America/New_York]",
+);
+const end = start.subtract({
+  years: 1,
+  months: 2,
+  weeks: 3,
+  days: 4,
+  hours: 5,
+  minutes: 6,
+  seconds: 7,
+  milliseconds: 8,
+});
+console.log(end.toString()); // 2019-10-07T07:28:48.992-04:00[America/New_York]
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/ZonedDateTime/add", "Temporal.ZonedDateTime.prototype.add()")}}
+- {{jsxref("Temporal/ZonedDateTime/since", "Temporal.ZonedDateTime.prototype.since()")}}
+- {{jsxref("Temporal/ZonedDateTime/until", "Temporal.ZonedDateTime.prototype.until()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/timezoneid/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/timezoneid/index.md
new file mode 100644
index 000000000000000..c39cfb485e35ed8
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/timezoneid/index.md
@@ -0,0 +1,74 @@
+---
+title: Temporal.ZonedDateTime.prototype.timeZoneId
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/timeZoneId
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.timeZoneId
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`timeZoneId`** accessor property of {{jsxref("Temporal.ZonedDateTime")}} instances returns a string representing the [time zone identifier](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#time_zones_and_offsets) used to interpret the internal instant. The string is either a named identifier in the preferred case (such as `"America/New_York"`), or an offset in the form `"±hh:mm"`. If the time zone has aliases, the `timeZoneId` is the identifier used to create the `ZonedDateTime`, without canonicalization to the primary identifier.
+
+The set accessor of `timeZoneId` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/ZonedDateTime/withTimeZone", "withTimeZone()")}} method to create a new `Temporal.ZonedDateTime` object with the desired new value.
+
+> [!NOTE]
+> This string is not intended for display to users. Use {{jsxref("Temporal/ZonedDateTime/toLocaleString", "toLocaleString()")}} with the appropriate options to get a localized string.
+
+## Examples
+
+### Using timeZoneId
+
+```js
+const dt = Temporal.ZonedDateTime.from(
+  "2021-07-01T12:00:00-07:00[America/Los_Angeles]",
+);
+console.log(dt.timeZoneId); // "America/Los_Angeles"
+
+const dt2 = Temporal.ZonedDateTime.from("2021-07-01T12:00:00-07:00[-07:00]");
+console.log(dt2.timeZoneId); // "-07:00"
+
+const dt3 = dt2.withTimeZone("Asia/Shanghai");
+console.log(dt3.timeZoneId); // "Asia/Shanghai"
+```
+
+The `timeZoneId` is never canonicalized to the primary identifier; it is the same as the one used to create the `ZonedDateTime`.
+
+```js
+const dt = Temporal.ZonedDateTime.from(
+  "2021-07-01T12:00:00+07:00[Asia/Ho_Chi_Minh]",
+);
+const dt2 = Temporal.ZonedDateTime.from(
+  "2021-07-01T12:00:00+07:00[Asia/Saigon]",
+);
+console.log(dt.timeZoneId); // "Asia/Ho_Chi_Minh"
+console.log(dt2.timeZoneId); // "Asia/Saigon"
+```
+
+However, presentational differences will get canonicalized.
+
+```js
+const dt = Temporal.ZonedDateTime.from(
+  "2021-07-01T12:00:00+07:00[asia/ho_chi_minh]",
+);
+console.log(dt.timeZoneId); // "Asia/Ho_Chi_Minh"
+
+const dt2 = Temporal.ZonedDateTime.from("2021-07-01T12:00:00+07:00[+07]");
+console.log(dt2.timeZoneId); // "+07:00"
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/withTimeZone", "Temporal.ZonedDateTime.prototype.withTimeZone()")}}
+- {{jsxref("Temporal/ZonedDateTime/offset", "Temporal.ZonedDateTime.prototype.offset")}}
+- {{jsxref("Temporal/ZonedDateTime/offsetNanoseconds", "Temporal.ZonedDateTime.prototype.offsetNanoseconds")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/toinstant/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/toinstant/index.md
new file mode 100644
index 000000000000000..09fafa2dd850431
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/toinstant/index.md
@@ -0,0 +1,55 @@
+---
+title: Temporal.ZonedDateTime.prototype.toInstant()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/toInstant
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.toInstant
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toInstant()`** method of {{jsxref("Temporal.ZonedDateTime")}} instances returns a new {{jsxref("Temporal.Instant")}} object representing the instant of this date-time.
+
+## Syntax
+
+```js-nolint
+toInstant()
+```
+
+### Parameters
+
+None.
+
+### Return value
+
+A new {{jsxref("Temporal.Instant")}} object representing the instant of this date-time.
+
+## Examples
+
+### Using toInstant()
+
+```js
+const zdt = Temporal.ZonedDateTime.from(
+  "2021-07-01T12:34:56.987654321-04:00[America/New_York]",
+);
+const instant = zdt.toInstant();
+console.log(instant.toString()); // 2021-07-01T16:34:56.987654321Z
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal.Instant")}}
+- {{jsxref("Temporal/ZonedDateTime/toPlainDate", "Temporal.ZonedDateTime.prototype.toPlainDate()")}}
+- {{jsxref("Temporal/ZonedDateTime/toPlainTime", "Temporal.ZonedDateTime.prototype.toPlainTime()")}}
+- {{jsxref("Temporal/ZonedDateTime/toPlainDateTime", "Temporal.ZonedDateTime.prototype.toPlainDateTime()")}}
+- {{jsxref("Temporal/Instant/toZonedDateTimeISO", "Temporal.Instant.prototype.toZonedDateTimeISO()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/tojson/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/tojson/index.md
new file mode 100644
index 000000000000000..64fdd308cb5b84f
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/tojson/index.md
@@ -0,0 +1,80 @@
+---
+title: Temporal.ZonedDateTime.prototype.toJSON()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/toJSON
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.toJSON
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toJSON()`** method of {{jsxref("Temporal.ZonedDateTime")}} instances returns a string representing this date-time in the same [RFC 9557 format](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#rfc_9557_format) as calling {{jsxref("Temporal/ZonedDateTime/toString", "toString()")}}. It is intended to be implicitly called by {{jsxref("JSON.stringify()")}}.
+
+## Syntax
+
+```js-nolint
+toJSON()
+```
+
+### Parameters
+
+None.
+
+### Return value
+
+A string representing the given date-time in the [RFC 9557 format](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#rfc_9557_format), with the calendar annotation included if it is not `"iso8601"`, and the offset and time zone annotation always included.
+
+## Description
+
+The `toJSON()` method is automatically called by {{jsxref("JSON.stringify()")}} when a `Temporal.ZonedDateTime` object is stringified. This method is generally intended to, by default, usefully serialize `Temporal.ZonedDateTime` objects during [JSON](/en-US/docs/Glossary/JSON) serialization, which can then be deserialized using the {{jsxref("Temporal/ZonedDateTime/from", "Temporal.ZonedDateTime.from()")}} function as the reviver of {{jsxref("JSON.parse()")}}.
+
+## Examples
+
+### Using toJSON()
+
+```js
+const zdt = Temporal.ZonedDateTime.from({
+  year: 2021,
+  month: 8,
+  day: 1,
+  timeZone: "America/New_York",
+});
+const zdtStr = zdt.toJSON(); // '2021-08-01T00:00:00-04:00[America/New_York]'
+const zdt2 = Temporal.ZonedDateTime.from(zdtStr);
+```
+
+### JSON serialization and parsing
+
+This example shows how `Temporal.ZonedDateTime` can be serialized as JSON without extra effort, and how to parse it back.
+
+```js
+const zdt = Temporal.ZonedDateTime.from({
+  year: 2021,
+  month: 8,
+  day: 1,
+  timeZone: "America/New_York",
+});
+const jsonStr = JSON.stringify({ meeting: zdt }); // '{"meeting":"2021-08-01T00:00:00-04:00[America/New_York]"}'
+const obj = JSON.parse(jsonStr, (key, value) => {
+  if (key === "meeting") {
+    return Temporal.ZonedDateTime.from(value);
+  }
+  return value;
+});
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/from", "Temporal.ZonedDateTime.from()")}}
+- {{jsxref("Temporal/ZonedDateTime/toString", "Temporal.ZonedDateTime.prototype.toString()")}}
+- {{jsxref("Temporal/ZonedDateTime/toLocaleString", "Temporal.ZonedDateTime.prototype.toLocaleString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/tolocalestring/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/tolocalestring/index.md
new file mode 100644
index 000000000000000..8d765eba9fd2320
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/tolocalestring/index.md
@@ -0,0 +1,123 @@
+---
+title: Temporal.ZonedDateTime.prototype.toLocaleString()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/toLocaleString
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.toLocaleString
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toLocaleString()`** method of {{jsxref("Temporal.ZonedDateTime")}} instances returns a string with a language-sensitive representation of this date-time. In implementations with [`Intl.DateTimeFormat` API](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat) support, this method delegates to `Intl.DateTimeFormat` and passes this date-time converted to an {{jsxref("Temporal.Instant")}} (because `Intl.DateTimeFormat` cannot directly format a `Temporal.ZonedDateTime`).
+
+Every time `toLocaleString` is called, it has to perform a search in a big database of localization strings, which is potentially inefficient. When the method is called many times with the same arguments, it is better to create a {{jsxref("Intl.DateTimeFormat")}} object and use its {{jsxref("Intl/DateTimeFormat/format", "format()")}} method, because a `DateTimeFormat` object remembers the arguments passed to it and may decide to cache a slice of the database, so future `format` calls can search for localization strings within a more constrained context. However, currently `Intl.DateTimeFormat` does not support formatting `Temporal.ZonedDateTime` objects, so you must convert them to `Temporal.Instant` objects first before passing them to `format()`.
+
+## Syntax
+
+```js-nolint
+toLocaleString()
+toLocaleString(locales)
+toLocaleString(locales, options)
+```
+
+### Parameters
+
+The `locales` and `options` parameters customize the behavior of the function and let applications specify the language whose formatting conventions should be used.
+
+In implementations that support the [`Intl.DateTimeFormat` API](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat), these parameters correspond exactly to the [`Intl.DateTimeFormat()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat/DateTimeFormat) constructor's parameters. Implementations without `Intl.DateTimeFormat` support return the exact same string as {{jsxref("Temporal/ZonedDateTime/toString", "toString()")}}, ignoring both parameters.
+
+- `locales` {{optional_inline}}
+  - : A string with a BCP 47 language tag, or an array of such strings. Corresponds to the [`locales`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat/DateTimeFormat#locales) parameter of the `Intl.DateTimeFormat()` constructor.
+- `options` {{optional_inline}}
+
+  - : An object adjusting the output format. Corresponds to the [`options`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat/DateTimeFormat#options) parameter of the `Intl.DateTimeFormat()` constructor. If this date-time's calendar is not `"iso8601"`, the `calendar` option must be provided with the same value; otherwise, if this date-time's calendar is `"iso8601"`, the `calendar` option can be any value. The `timeZone` option must not be provided, as it is automatically set to be the date-time's {{jsxref("Temporal/ZonedDateTime/timeZoneId", "timeZoneId")}}. Regarding the [date-time component options](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat/DateTimeFormat#date-time_component_options) and the style shortcuts (`dateStyle` and `timeStyle`), the options should follow one of these forms:
+
+    - Provide none of them: `year`, `month`, `day`, `hour`, `minute`, and `second` will default to `"numeric"`.
+    - Provide at least one of `dateStyle` or `timeStyle`: the date-time components will be set according to the specified style and the locale.
+    - Provide some date-time component options. Only the specified date-time components will be included in the output.
+
+See the [`Intl.DateTimeFormat()` constructor](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat/DateTimeFormat) for details on these parameters and how to use them.
+
+### Return value
+
+A string representing the given date-time according to language-specific conventions.
+
+In implementations with `Intl.DateTimeFormat`, this is equivalent to `new Intl.DateTimeFormat(locales, options).format(dateTime.toInstant())`, where `options` has been normalized as described above.
+
+> [!NOTE]
+> Most of the time, the formatting returned by `toLocaleString()` is consistent. However, the output may vary between implementations, even within the same locale — output variations are by design and allowed by the specification. It may also not be what you expect. For example, the string may use non-breaking spaces or be surrounded by bidirectional control characters. You should not compare the results of `toLocaleString()` to hardcoded constants.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown if any of the options is invalid.
+- {{jsxref("TypeError")}}
+  - : Thrown if any of the options is not of the expected type.
+
+## Examples
+
+### Using toLocaleString()
+
+Basic use of this method without specifying a `locale` returns a formatted string in the default locale and with default options.
+
+```js
+const zdt = Temporal.ZonedDateTime.from(
+  "2021-08-01T12:34:56-04:00[America/New_York]",
+);
+
+console.log(zdt.toLocaleString()); // 8/1/2021, 12:34:56 PM EDT (assuming en-US locale)
+```
+
+If the date's calendar doesn't match the locale's default calendar, and the date's calendar is not `iso8601`, an explicit `calendar` option must be provided with the same value.
+
+```js
+const zdt = Temporal.ZonedDateTime.from(
+  "2021-08-01T12:34:56+09:00[Asia/Tokyo][u-ca=japanese]",
+);
+// The ja-JP locale uses the Gregorian calendar by default
+zdt.toLocaleString("ja-JP", { calendar: "japanese" }); // R3/8/1 12:34:56 JST
+```
+
+### Using toLocaleString() with options
+
+You can customize which parts of the date are included in the output by providing the `options` parameter.
+
+```js
+const zdt = Temporal.ZonedDateTime.from(
+  "2021-08-01T12:34:56+09:00[Asia/Tokyo][u-ca=japanese]",
+);
+zdt.toLocaleString("ja-JP", {
+  calendar: "japanese",
+  dateStyle: "full",
+  timeStyle: "full",
+}); // 令和3年8月1日日曜日 12時34分56秒 日本標準時
+zdt.toLocaleString("ja-JP", {
+  calendar: "japanese",
+  year: "numeric",
+  month: "long",
+  hour: "numeric",
+  timeZoneName: "shortGeneric",
+}); // 令和3年8月 12時 JST
+zdt.toLocaleString("ja-JP", {
+  calendar: "japanese",
+  year: "numeric",
+  hour: "numeric",
+  minute: "numeric",
+}); // 令和3年 12:34
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Intl.DateTimeFormat")}}
+- {{jsxref("Temporal/ZonedDateTime/toJSON", "Temporal.ZonedDateTime.prototype.toJSON()")}}
+- {{jsxref("Temporal/ZonedDateTime/toString", "Temporal.ZonedDateTime.prototype.toString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/toplaindate/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/toplaindate/index.md
new file mode 100644
index 000000000000000..9cea5a04b6a6e46
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/toplaindate/index.md
@@ -0,0 +1,55 @@
+---
+title: Temporal.ZonedDateTime.prototype.toPlainDate()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/toPlainDate
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.toPlainDate
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toPlainDate()`** method of {{jsxref("Temporal.ZonedDateTime")}} instances returns a new {{jsxref("Temporal.PlainDate")}} object representing the date portion of this date-time.
+
+## Syntax
+
+```js-nolint
+toPlainDate()
+```
+
+### Parameters
+
+None.
+
+### Return value
+
+A new {{jsxref("Temporal.PlainDate")}} object representing the date portion of this date-time.
+
+## Examples
+
+### Using toPlainDate()
+
+```js
+const zdt = Temporal.ZonedDateTime.from(
+  "2021-07-01T12:34:56.987654321-04:00[America/New_York]",
+);
+const plainDate = zdt.toPlainDate();
+console.log(plainDate.toString()); // 2021-07-01
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal.PlainDate")}}
+- {{jsxref("Temporal/ZonedDateTime/toPlainTime", "Temporal.ZonedDateTime.prototype.toPlainTime()")}}
+- {{jsxref("Temporal/ZonedDateTime/toPlainDateTime", "Temporal.ZonedDateTime.prototype.toPlainDateTime()")}}
+- {{jsxref("Temporal/ZonedDateTime/toInstant", "Temporal.ZonedDateTime.prototype.toInstant()")}}
+- {{jsxref("Temporal/PlainDate/toZonedDateTime", "Temporal.PlainDate.prototype.toZonedDateTime()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/toplaindatetime/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/toplaindatetime/index.md
new file mode 100644
index 000000000000000..4a3c1c4d3c6a6e2
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/toplaindatetime/index.md
@@ -0,0 +1,58 @@
+---
+title: Temporal.ZonedDateTime.prototype.toPlainDateTime()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/toPlainDateTime
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.toPlainDateTime
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toPlainDateTime()`** method of {{jsxref("Temporal.ZonedDateTime")}} instances returns a new {{jsxref("Temporal.PlainDateTime")}} object representing the date and time portions of this date-time. Only the time zone information is removed.
+
+> [!WARNING]
+> After a `Temporal.ZonedDateTime` is converted to `Temporal.PlainDateTime`, it's no longer time-zone-aware. Subsequent operations like arithmetic or `with()` operations will not adjust for DST and may not yield the same results as equivalent operations with the original `Temporal.ZonedDateTime`. However, unless you perform those operations across a time zone offset transition, it's impossible to notice the difference. Therefore, be very careful when performing this conversion because subsequent results may be correct most of the time, but only turn out incorrect when moving across offset transitions like when DST starts or ends.
+
+## Syntax
+
+```js-nolint
+toPlainDateTime()
+```
+
+### Parameters
+
+None.
+
+### Return value
+
+A new {{jsxref("Temporal.PlainDateTime")}} object representing the date and time portions of this date-time.
+
+## Examples
+
+### Using toPlainDateTime()
+
+```js
+const zdt = Temporal.ZonedDateTime.from(
+  "2021-07-01T12:34:56.987654321-04:00[America/New_York]",
+);
+const plainDateTime = zdt.toPlainDateTime();
+console.log(plainDateTime.toString()); // 2021-07-01T12:34:56.987654321
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal.PlainDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/toPlainDate", "Temporal.ZonedDateTime.prototype.toPlainDate()")}}
+- {{jsxref("Temporal/ZonedDateTime/toPlainTime", "Temporal.ZonedDateTime.prototype.toPlainTime()")}}
+- {{jsxref("Temporal/ZonedDateTime/toInstant", "Temporal.ZonedDateTime.prototype.toInstant()")}}
+- {{jsxref("Temporal/PlainDateTime/toZonedDateTime", "Temporal.PlainDateTime.prototype.toZonedDateTime()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/toplaintime/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/toplaintime/index.md
new file mode 100644
index 000000000000000..edd3691010bd404
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@@ -0,0 +1,57 @@
+---
+title: Temporal.ZonedDateTime.prototype.toPlainTime()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/toPlainTime
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.toPlainTime
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toPlainTime()`** method of {{jsxref("Temporal.ZonedDateTime")}} instances returns a new {{jsxref("Temporal.PlainTime")}} object representing the time portion of this date-time.
+
+> [!WARNING]
+> After a `Temporal.ZonedDateTime` is converted to `Temporal.PlainTime`, it's no longer time-zone-aware. Subsequent operations like arithmetic or `with()` operations will not adjust for DST and may not yield the same results as equivalent operations with the original `Temporal.ZonedDateTime`. However, unless you perform those operations across a time zone offset transition, it's impossible to notice the difference. Therefore, be very careful when performing this conversion because subsequent results may be correct most of the time, but only turn out incorrect when moving across offset transitions like when DST starts or ends.
+
+## Syntax
+
+```js-nolint
+toPlainTime()
+```
+
+### Parameters
+
+None.
+
+### Return value
+
+A new {{jsxref("Temporal.PlainTime")}} object representing the time portion of this date-time.
+
+## Examples
+
+### Using toPlainTime()
+
+```js
+const zdt = Temporal.ZonedDateTime.from(
+  "2021-07-01T12:34:56.987654321-04:00[America/New_York]",
+);
+const plainTime = zdt.toPlainTime();
+console.log(plainTime.toString()); // 12:34:56.987654321
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal.PlainTime")}}
+- {{jsxref("Temporal/ZonedDateTime/toPlainDate", "Temporal.ZonedDateTime.prototype.toPlainDate()")}}
+- {{jsxref("Temporal/ZonedDateTime/toPlainDateTime", "Temporal.ZonedDateTime.prototype.toPlainDateTime()")}}
+- {{jsxref("Temporal/ZonedDateTime/toInstant", "Temporal.ZonedDateTime.prototype.toInstant()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/tostring/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/tostring/index.md
new file mode 100644
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--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/tostring/index.md
@@ -0,0 +1,112 @@
+---
+title: Temporal.ZonedDateTime.prototype.toString()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/toString
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.toString
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`toString()`** method of {{jsxref("Temporal.ZonedDateTime")}} instances returns a string representing this date-time in the [RFC 9557 format](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#rfc_9557_format).
+
+## Syntax
+
+```js-nolint
+toString()
+toString(options)
+```
+
+### Parameters
+
+- `options` {{optional_inline}}
+  - : An object containing the following property:
+    - `calendarName` {{optional_inline}}
+      - : Whether to show the calendar annotation (`[u-ca=calendar_id]`) in the return value. Possible values are:
+        - `"auto"` (default)
+          - : Include the calendar annotation if the calendar is not `"iso8601"`.
+        - `"always"`
+          - : Always include the calendar annotation.
+        - `"never"`
+          - : Never include the calendar annotation. This makes the returned string not recoverable to the same {{jsxref("Temporal.ZonedDateTime")}} instance, although the date value still remains the same.
+        - `"critical"`
+          - : Always include the calendar annotation, and add a critical flag: `[!u-ca=calendar_id]`. Useful when sending the string to certain systems, but not useful for Temporal itself.
+    - `fractionalSecondDigits` {{optional_inline}}
+      - : Either an integer from 0 to 9, or the string `"auto"`. The default is `"auto"`. If `"auto"`, then trailing zeros are removed from the fractional seconds. Otherwise, the fractional part of the second component contains this many digits, padded with zeros or rounded as necessary.
+    - `roundingMode` {{optional_inline}}
+      - : A string specifying how to round off fractional second digits beyond `fractionalSecondDigits`. See [`Intl.NumberFormat()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/NumberFormat/NumberFormat#roundingmode). Defaults to `"trunc"`.
+    - `smallestUnit` {{optional_inline}}
+      - : A string specifying the smallest unit to include in the output. Possible values are `"minute"`, `"second"`, `"millisecond"`, `"microsecond"`, and `"nanosecond"`, or their plural forms, which (except `"minute"`) are equivalent to `fractionalSecondDigits` values of `0`, `3`, `6`, `9`, respectively. If specified, then `fractionalSecondDigits` is ignored.
+    - `timeZoneName` {{optional_inline}}
+      - : Whether to show the time zone name (`[time_zone_id]`) in the return value. Possible values are:
+        - `"auto"` (default)
+          - : Always include the time zone name.
+        - `"never"`
+          - : Never include the time zone name. This makes the returned string not recoverable to the same {{jsxref("Temporal.ZonedDateTime")}} instance.
+        - `"critical"`
+          - : Always include the time zone name, and add a critical flag: `[!time)zone_id]`. Useful when sending the string to certain systems, but not useful for Temporal itself.
+    - `offset` {{optional_inline}}
+      - : Whether to show the offset (`±HH:mm`) in the return value. Possible values are:
+        - `"auto"` (default)
+          - : Always include the offset.
+        - `"never"`
+          - : Never include the offset. This makes the returned string not recoverable to the same {{jsxref("Temporal.ZonedDateTime")}} instance, if the time zone is included but the time is ambiguous, or if the time zone is also not included.
+
+### Return value
+
+A string in the [RFC 9557 format](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#rfc_9557_format) representing this date-time. The offset and calendar/time zone annotations are included as specified.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown if any of the options is invalid.
+- {{jsxref("TypeError")}}
+  - : Thrown if `options` is not an object or `undefined`.
+
+## Examples
+
+### Using toString()
+
+```js
+const zdt = Temporal.ZonedDateTime.from(
+  "2021-08-01T12:34:56[America/New_York]",
+);
+console.log(zdt.toString()); // '2021-08-01T12:34:56-04:00[America/New_York]'
+```
+
+Even for the `UTC` time zone, the offset is `+00:00`, not `Z`:
+
+```js
+const zdt = Temporal.ZonedDateTime.from("2021-08-01T12:34:56[UTC]");
+console.log(zdt.toString()); // '2021-08-01T12:34:56+00:00[UTC]'
+```
+
+### Using options
+
+For examples with rounding times, see {{jsxref("Temporal/PlainTime/toString", "Temporal.PlainTime.prototype.toString()")}}. For examples with displaying calendars, see {{jsxref("Temporal/PlainDate/toString", "Temporal.PlainDate.prototype.toString()")}}. Here we show controlling the display of time zone and offset:
+
+```js
+const zdt = Temporal.ZonedDateTime.from(
+  "2021-08-01T12:34:56[America/New_York]",
+);
+console.log(zdt.toString({ timeZoneName: "auto", offset: "never" })); // '2021-08-01T12:34:56[America/New_York]'
+console.log(zdt.toString({ timeZoneName: "never", offset: "auto" })); // '2021-08-01T12:34:56-04:00'
+console.log(zdt.toString({ timeZoneName: "never", offset: "never" })); // '2021-08-01T12:34:56'
+console.log(zdt.toString({ timeZoneName: "critical", offset: "never" })); // '2021-08-01T12:34:56[!America/New_York]'
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/from", "Temporal.ZonedDateTime.from()")}}
+- {{jsxref("Temporal/ZonedDateTime/toJSON", "Temporal.ZonedDateTime.prototype.toJSON()")}}
+- {{jsxref("Temporal/ZonedDateTime/toLocaleString", "Temporal.ZonedDateTime.prototype.toLocaleString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/until/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/until/index.md
new file mode 100644
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--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/until/index.md
@@ -0,0 +1,76 @@
+---
+title: Temporal.ZonedDateTime.prototype.until()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/until
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.until
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`until()`** method of {{jsxref("Temporal.ZonedDateTime")}} instances returns a new {{jsxref("Temporal.Duration")}} object representing the duration from this date-time to another date-time (in a form convertible by {{jsxref("Temporal/ZonedDateTime/from", "Temporal.ZonedDateTime.from()")}}). The duration is positive if the other date-time is after this date-time, and negative if before.
+
+This method does `other - this`. To do `this - other`, use the {{jsxref("Temporal/ZonedDateTime/since", "since()")}} method.
+
+## Syntax
+
+```js-nolint
+until(other)
+until(other, options)
+```
+
+### Parameters
+
+- `other`
+  - : A string, an object, or a {{jsxref("Temporal.ZonedDateTime")}} instance representing a date-time to subtract this date-time from. It is converted to a `Temporal.ZonedDateTime` object using the same algorithm as {{jsxref("Temporal/ZonedDateTime/from", "Temporal.ZonedDateTime.from()")}}. It must have the same calendar as `this`.
+- `options` {{optional_inline}}
+  - : The same options as [`since()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/since#options).
+
+### Return value
+
+A new {{jsxref("Temporal.Duration")}} object representing the duration from this date-time _until_ `other`. The duration is positive if `other` is after this date-time, and negative if before.
+
+### Exceptions
+
+- {{jsxref("RangeError")}}
+  - : Thrown in one of the following cases:
+    - `other` has a different calendar than `this`.
+    - Any of the options is invalid.
+    - `other` has a different time zone than `this`, and `largestUnit` is `"day"` or above.
+
+## Examples
+
+### Using until()
+
+```js
+const flight = Temporal.ZonedDateTime.from(
+  "2024-12-21T13:31:00-05:00[America/New_York]",
+);
+const now = Temporal.Now.zonedDateTimeISO("America/New_York").round("second");
+if (Temporal.ZonedDateTime.compare(flight, now) < 0) {
+  console.error(
+    "The flight is already in the past. The result may not make sense.",
+  );
+}
+const duration = now.until(flight, { largestUnit: "day" });
+console.log(`The flight is in ${duration.toLocaleString("en-US")}`);
+```
+
+For more examples, see [`since()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/since).
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal.Duration")}}
+- {{jsxref("Temporal/ZonedDateTime/add", "Temporal.ZonedDateTime.prototype.add()")}}
+- {{jsxref("Temporal/ZonedDateTime/subtract", "Temporal.ZonedDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/ZonedDateTime/since", "Temporal.ZonedDateTime.prototype.since()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/valueof/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/valueof/index.md
new file mode 100644
index 000000000000000..d8fa8ec0010fbfa
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/valueof/index.md
@@ -0,0 +1,70 @@
+---
+title: Temporal.ZonedDateTime.prototype.valueOf()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/valueOf
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.valueOf
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`valueOf()`** method of {{jsxref("Temporal.ZonedDateTime")}} instances throws a {{jsxref("TypeError")}}, which prevents `Temporal.ZonedDateTime` instances from being [implicitly converted to primitives](/en-US/docs/Web/JavaScript/Data_structures#primitive_coercion) when used in arithmetic or comparison operations.
+
+## Syntax
+
+```js-nolint
+valueOf()
+```
+
+### Parameters
+
+None.
+
+### Return value
+
+None.
+
+### Exceptions
+
+- {{jsxref("TypeError")}}
+  - : Always thrown.
+
+## Description
+
+Because both [primitive conversion](/en-US/docs/Web/JavaScript/Data_structures#primitive_coercion) and [number conversion](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number#number_coercion) call `valueOf()` before `toString()`, if `valueOf()` is absent, then an expression like `yearMonth1 > yearMonth2` would implicitly compare them as strings, which may have unexpected results. By throwing a `TypeError`, `Temporal.ZonedDateTime` instances prevent such implicit conversions. You need to explicitly convert them to numbers using {{jsxref("Temporal/ZonedDateTime/epochNanoseconds", "Temporal.ZonedDateTime.prototype.epochNanoseconds")}}, or use the {{jsxref("Temporal/ZonedDateTime/compare", "Temporal.ZonedDateTime.compare()")}} static method to compare them.
+
+## Examples
+
+### Arithmetic and comparison operations on Temporal.ZonedDateTime
+
+All arithmetic and comparison operations on `Temporal.ZonedDateTime` instances should use the dedicated methods or convert them to primitives explicitly.
+
+```js
+const zdt1 = Temporal.ZonedDateTime.from(
+  "2022-01-01T00:00:00[America/New_York]",
+);
+const zdt2 = Temporal.ZonedDateTime.from(
+  "2022-07-01T00:00:00[America/New_York]",
+);
+zdt1 > zdt2; // TypeError: can't convert ZonedDateTime to primitive type
+Temporal.ZonedDateTime.compare(zdt1, zdt2); // -1
+
+zdt2 - zdt1; // TypeError: can't convert ZonedDateTime to primitive type
+zdt2.since(zdt1).toString(); // "PT4343H"
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/toString", "Temporal.ZonedDateTime.prototype.toString()")}}
+- {{jsxref("Temporal/ZonedDateTime/toJSON", "Temporal.ZonedDateTime.prototype.toJSON()")}}
+- {{jsxref("Temporal/ZonedDateTime/toLocaleString", "Temporal.ZonedDateTime.prototype.toLocaleString()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/weekofyear/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/weekofyear/index.md
new file mode 100644
index 000000000000000..4d7bd45de2a2b66
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/weekofyear/index.md
@@ -0,0 +1,45 @@
+---
+title: Temporal.ZonedDateTime.prototype.weekOfYear
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/weekOfYear
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.weekOfYear
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`weekOfYear`** accessor property of {{jsxref("Temporal.ZonedDateTime")}} instances returns a positive integer representing the 1-based week index in the {{jsxref("Temporal/ZonedDateTime/yearOfWeek", "yearOfWeek")}} of this date, or `undefined` if the calendar does not have a well-defined week system. The first week of the year is `1`. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+The set accessor of `weekOfYear` is `undefined`. You cannot change this property directly. To create a new `Temporal.ZonedDateTime` object with the desired new `weekOfYear` value, use the {{jsxref("Temporal/ZonedDateTime/add", "add()")}} or {{jsxref("Temporal/ZonedDateTime/subtract", "subtract()")}} method with the appropriate number of `weeks`.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/weekOfYear", "Temporal.PlainDate.prototype.weekOfYear")}}.
+
+## Examples
+
+### Using weekOfYear
+
+```js
+const dt = Temporal.ZonedDateTime.from("2021-07-01[America/New_York]");
+console.log(dt.weekOfYear); // 26
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/with", "Temporal.ZonedDateTime.prototype.with()")}}
+- {{jsxref("Temporal/ZonedDateTime/add", "Temporal.ZonedDateTime.prototype.add()")}}
+- {{jsxref("Temporal/ZonedDateTime/subtract", "Temporal.ZonedDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/ZonedDateTime/yearOfWeek", "Temporal.ZonedDateTime.prototype.yearOfWeek")}}
+- {{jsxref("Temporal/ZonedDateTime/dayOfWeek", "Temporal.ZonedDateTime.prototype.dayOfWeek")}}
+- {{jsxref("Temporal/ZonedDateTime/daysInWeek", "Temporal.ZonedDateTime.prototype.daysInWeek")}}
+- {{jsxref("Temporal/ZonedDateTime/daysInYear", "Temporal.ZonedDateTime.prototype.daysInYear")}}
+- {{jsxref("Temporal/PlainDate/weekOfYear", "Temporal.PlainDate.prototype.weekOfYear")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/with/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/with/index.md
new file mode 100644
index 000000000000000..5ff4d5420d120ca
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/with/index.md
@@ -0,0 +1,138 @@
+---
+title: Temporal.ZonedDateTime.prototype.with()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/with
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.with
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`with()`** method of {{jsxref("Temporal.ZonedDateTime")}} instances returns a new `Temporal.ZonedDateTime` object representing this date-time with some fields replaced by new values. Because all `Temporal` objects are designed to be immutable, this method essentially functions as the setter for the date-time's fields.
+
+To replace the {{jsxref("Temporal/ZonedDateTime/calendarId", "calendarId")}} property, use the {{jsxref("Temporal/ZonedDateTime/withCalendar", "withCalendar()")}} method. To replace the {{jsxref("Temporal/ZonedDateTime/timeZoneId", "timeZoneId")}} property, use the {{jsxref("Temporal/ZonedDateTime/withTimeZone", "withTimeZone()")}} method.
+
+## Syntax
+
+```js-nolint
+with(info)
+with(info, options)
+```
+
+### Parameters
+
+- `info`
+  - : An object containing at least one of the properties recognized by {{jsxref("Temporal/ZonedDateTime/from", "Temporal.ZonedDateTime.from()")}} (except `calendar`): `day`, `era` and `eraYear`, `hour`, `microsecond`, `millisecond`, `minute`, `month`, `monthCode`, `nanosecond`, `offset`, `second`, `year`. Unspecified properties use the values from the original date-time. You only need to provide one of `month` or `monthCode`, and one of `era` and `eraYear` or `year`, and the other will be updated accordingly.
+- `options` {{optional_inline}}
+  - : An object containing some or all of the following properties (in the order they are retrieved and validated):
+    - `disambiguation` {{optional_inline}}
+      - : What to do if the local date-time is ambiguous in the given time zone (there are more than one instants with such local time, or the local time does not exist). Possible values are `"compatible"`, `"earlier"`, `"later"`, and `"reject"`. Defaults to `"compatible"`. For more information about these values, see [ambiguity and gaps from local time to UTC time](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#ambiguity_and_gaps_from_local_time_to_utc_time).
+    - `offset` {{optional_inline}}
+      - : What to do if the offset is explicitly provided in `info` but the offset is invalid for the given time zone in the given local time. Possible values are `"use"`, `"ignore"`, `"reject"`, and `"prefer"`. Defaults to `"prefer"`. For more information about these values, see [offset ambiguity](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#offset_ambiguity).
+    - `overflow` {{optional_inline}}
+      - : A string specifying the behavior when a date component is out of range (when using the object `info`). Possible values are:
+        - `"constrain"` (default)
+          - : The date component is [clamped](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate#invalid_date_clamping) to the valid range.
+        - `"reject"`
+          - : A {{jsxref("RangeError")}} is thrown if the date component is out of range.
+
+### Return value
+
+A new `Temporal.ZonedDateTime` object, where the fields specified in `info` that are not `undefined` are replaced by the corresponding values, and the rest of the fields are copied from the original date-time.
+
+### Exceptions
+
+- {{jsxref("TypeError")}}
+  - : Thrown in one of the following cases:
+    - `info` is not an object.
+    - `options` is not an object or `undefined`.
+- {{jsxref("RangeError")}}
+  - : Thrown in one of the following cases:
+    - The provided properties that specify the same component are inconsistent.
+    - The provided non-numerical properties are not valid; for example, if `monthCode` is never a valid month code in this calendar.
+    - The provided numerical properties are out of range, and `options.overflow` is set to `"reject"`.
+
+## Examples
+
+### Using with()
+
+```js
+const zdt = Temporal.ZonedDateTime.from(
+  "2021-07-01T12:34:56[America/New_York]",
+);
+const newZDT = zdt.with({ hour: 13 });
+console.log(newZDT.toString()); // "2021-07-01T13:34:56-04:00[America/New_York]"
+```
+
+For more examples, see the documentation for the individual properties that can be set using `with()`.
+
+### Offset during date changes
+
+By default, the `offset` option is set to `"prefer"`, which means we use the original offset (or that provided in `info`) if it's valid, and recalculate otherwise. This means if you set to another date that has a different offset due to a DST transition, the offset will be recalculated:
+
+```js
+const zdt = Temporal.ZonedDateTime.from(
+  "2021-07-01T12:00:00-04:00[America/New_York]",
+);
+const newZDT = zdt.with({ month: 12 });
+// The offset is recalculated to -05:00
+console.log(newZDT.toString()); // "2021-12-01T12:00:00-05:00[America/New_York]"
+```
+
+And if you set the time to within the DST transition, the offset is used to resolve the ambiguity:
+
+```js
+const zdt = Temporal.ZonedDateTime.from(
+  "2024-11-02T01:05:00-04:00[America/New_York]",
+);
+const newZDT = zdt.with({ day: 3 });
+console.log(newZDT.toString()); // "2024-11-03T01:05:00-04:00[America/New_York]"
+
+const zdt2 = Temporal.ZonedDateTime.from(
+  "2024-11-04T01:05:00-05:00[America/New_York]",
+);
+const newZDT2 = zdt2.with({ day: 3 });
+console.log(newZDT2.toString()); // "2024-11-03T01:05:00-05:00[America/New_York]"
+```
+
+If you use `offset: "use"`, then the offset will be used as-is to obtain the exact time first, and _then_ recalculate the offset:
+
+```js
+const zdt = Temporal.ZonedDateTime.from(
+  "2021-07-01T12:00:00-04:00[America/New_York]",
+);
+const newZDT = zdt.with({ month: 12 }, { offset: "use" });
+// The offset is recalculated to -05:00, but the wall-clock time changes
+console.log(newZDT.toString()); // "2021-12-01T11:00:00-05:00[America/New_York]"
+```
+
+You can also set `offset: "reject"` to throw an error if the original offset is invalid, forcing an explicit new offset to be specified:
+
+```js
+const zdt = Temporal.ZonedDateTime.from(
+  "2021-07-01T12:00:00-04:00[America/New_York]",
+);
+zdt.with({ month: 12 }, { offset: "reject" });
+// RangeError: date-time can't be represented in the given time zone
+zdt.with({ month: 12, offset: "-05:00" }, { offset: "reject" }).toString();
+// "2021-12-01T12:00:00-05:00[America/New_York]"
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/withCalendar", "Temporal.ZonedDateTime.prototype.withCalendar()")}}
+- {{jsxref("Temporal/ZonedDateTime/withTimeZone", "Temporal.ZonedDateTime.prototype.withTimeZone()")}}
+- {{jsxref("Temporal/ZonedDateTime/withPlainTime", "Temporal.ZonedDateTime.prototype.withPlainTime()")}}
+- {{jsxref("Temporal/ZonedDateTime/from", "Temporal.ZonedDateTime.from()")}}
+- {{jsxref("Temporal/ZonedDateTime/add", "Temporal.ZonedDateTime.prototype.add()")}}
+- {{jsxref("Temporal/ZonedDateTime/subtract", "Temporal.ZonedDateTime.prototype.subtract()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/withcalendar/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/withcalendar/index.md
new file mode 100644
index 000000000000000..43d087585b018d2
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/withcalendar/index.md
@@ -0,0 +1,66 @@
+---
+title: Temporal.ZonedDateTime.prototype.withCalendar()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/withCalendar
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.withCalendar
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`withCalendar()`** method of {{jsxref("Temporal.ZonedDateTime")}} instances returns a new `Temporal.ZonedDateTime` object representing this date-time interpreted in the new calendar system. Because all `Temporal` objects are designed to be immutable, this method essentially functions as the setter for the date-time's {{jsxref("Temporal/ZonedDateTime/calendarId", "calendarId")}} property.
+
+To replace the date-time component properties, use the {{jsxref("Temporal/ZonedDateTime/with", "with()")}} method. To replace its time zone, use the {{jsxref("Temporal/ZonedDateTime/withTimeZone", "withTimeZone()")}} method.
+
+## Syntax
+
+```js-nolint
+withCalendar(calendar)
+```
+
+### Parameters
+
+- `calendar`
+  - : A string that corresponds to the {{jsxref("Temporal/ZonedDateTime/calendarId", "calendarId")}} property.
+
+### Return value
+
+A new `Temporal.ZonedDateTime` object, representing the date-time specified by the original `ZonedDateTime`, interpreted in the new calendar system.
+
+### Exceptions
+
+- {{jsxref("TypeError")}}
+  - : Thrown if `calendar` is not a string.
+- {{jsxref("RangeError")}}
+  - : Thrown if `calendar` is not a valid calendar identifier.
+
+## Examples
+
+### Using withCalendar()
+
+```js
+const zdt = Temporal.ZonedDateTime.from(
+  "2021-07-01T12:34:56[America/New_York]",
+);
+const newZDT = zdt.withCalendar("islamic");
+console.log(newZDT.toLocaleString("en-US", { calendar: "islamic" }));
+// 11/21/1442 AH, 12:34:56 PM EDT
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/with", "Temporal.ZonedDateTime.prototype.with()")}}
+- {{jsxref("Temporal/ZonedDateTime/withTimeZone", "Temporal.ZonedDateTime.prototype.withTimeZone()")}}
+- {{jsxref("Temporal/ZonedDateTime/withPlainTime", "Temporal.ZonedDateTime.prototype.withPlainTime()")}}
+- {{jsxref("Temporal/ZonedDateTime/from", "Temporal.ZonedDateTime.from()")}}
+- {{jsxref("Temporal/ZonedDateTime/calendarId", "Temporal.ZonedDateTime.prototype.calendarId")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/withplaintime/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/withplaintime/index.md
new file mode 100644
index 000000000000000..50760e5cb2020b0
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/withplaintime/index.md
@@ -0,0 +1,76 @@
+---
+title: Temporal.ZonedDateTime.prototype.withPlainTime()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/withPlainTime
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.withPlainTime
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`withPlainTime()`** method of {{jsxref("Temporal.ZonedDateTime")}} instances returns a new `Temporal.ZonedDateTime` object representing this date-time with the time part entirely replaced by the new time (in a form convertible by {{jsxref("Temporal/PlainTime/from", "Temporal.PlainTime.from()")}})
+
+This method will replace all time properties, defaulting to `0` where properties are unspecified. If you only want to replace some of the time properties, use the {{jsxref("Temporal/ZonedDateTime/with", "with()")}} method instead.
+
+## Syntax
+
+```js-nolint
+withPlainTime()
+withPlainTime(plainTime)
+```
+
+### Parameters
+
+- `plainTime` {{optional_inline}}
+  - : A string, an object, or a {{jsxref("Temporal.PlainTime")}} instance representing the new time. It is converted to a `Temporal.PlainTime` object using the same algorithm as {{jsxref("Temporal/PlainTime/from", "Temporal.PlainTime.from()")}}. If not specified, the time part is set to the [start of the day](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/startOfDay) (which is usually `00:00:00` unless it doesn't exist due to offset transitions). [Disambiguation](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#time_zones_and_offsets) always happens in the `"compatible"` mode; if you want to use a different mode, use the {{jsxref("Temporal/ZonedDateTime/with", "with()")}} method instead.
+
+### Return value
+
+A new `Temporal.ZonedDateTime` object, with the date part and the time zone copied from the original date-time and the time part replaced by the new time.
+
+## Examples
+
+### Using withPlainTime()
+
+```js
+const zdt = Temporal.ZonedDateTime.from(
+  "2021-07-01T12:34:56[America/New_York]",
+);
+
+// You can pass a string
+const newZDT = zdt.withPlainTime("13:45:00");
+console.log(newZDT.toString()); // "2021-07-01T13:45:00-04:00[America/New_York]"
+
+// You can only specify some time properties, and the rest default to 0;
+// for the with() method, they would be copied from the original date-time
+const newZDT2 = zdt.withPlainTime({ hour: 13 });
+console.log(newZDT2.toString()); // "2021-07-01T13:00:00-04:00[America/New_York]"
+
+// You can pass nothing to set the time to midnight
+const newZDT3 = zdt.withPlainTime();
+console.log(newZDT3.toString()); // "2021-07-01T00:00:00-04:00[America/New_York]"
+
+// But, if midnight doesn't exist, it may be a different time
+const zdt2 = Temporal.ZonedDateTime.from(
+  "2015-10-18T12:00-02:00[America/Sao_Paulo]",
+);
+console.log(zdt2.withPlainTime().toString()); // "2015-10-18T01:00:00-02:00[America/Sao_Paulo]"
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/with", "Temporal.ZonedDateTime.prototype.with()")}}
+- {{jsxref("Temporal/ZonedDateTime/withCalendar", "Temporal.ZonedDateTime.prototype.withCalendar()")}}
+- {{jsxref("Temporal/ZonedDateTime/withTimeZone", "Temporal.ZonedDateTime.prototype.withTimeZone()")}}
+- {{jsxref("Temporal/ZonedDateTime/toPlainTime", "Temporal.ZonedDateTime.prototype.toPlainTime()")}}
+- {{jsxref("Temporal/ZonedDateTime/from", "Temporal.ZonedDateTime.from()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/withtimezone/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/withtimezone/index.md
new file mode 100644
index 000000000000000..55bb7c19b0d5fc6
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/withtimezone/index.md
@@ -0,0 +1,79 @@
+---
+title: Temporal.ZonedDateTime.prototype.withTimeZone()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/withTimeZone
+page-type: javascript-instance-method
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.withTimeZone
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`withTimeZone()`** method of {{jsxref("Temporal.ZonedDateTime")}} instances returns a new `Temporal.ZonedDateTime` object representing the same instant as this date-time but in the new time zone. Because all `Temporal` objects are designed to be immutable, this method essentially functions as the setter for the date-time's {{jsxref("Temporal/ZonedDateTime/timeZoneId", "timeZoneId")}} property.
+
+To replace the date-time component properties, use the {{jsxref("Temporal/ZonedDateTime/with", "with()")}} method. To replace its calendar, use the {{jsxref("Temporal/ZonedDateTime/withCalendar", "withCalendar()")}} method.
+
+## Syntax
+
+```js-nolint
+withTimeZone(timeZone)
+```
+
+### Parameters
+
+- `timeZone`
+  - : Either a string or a {{jsxref("Temporal.ZonedDateTime")}} instance representing the time zone to use. If a `Temporal.ZonedDateTime` instance, its time zone is used. If a string, it can be a named time zone identifier, an offset time zone identifier, or a date-time string containing a time zone identifier or an offset (see [time zones and offsets](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime#time_zones_and_offsets) for more information).
+
+### Return value
+
+A new `Temporal.ZonedDateTime` object representing the same instant as this date-time but in the new time zone.
+
+### Exceptions
+
+- {{jsxref("TypeError")}}
+  - : Thrown if `timeZone` is not a string or a `Temporal.ZonedDateTime` instance.
+- {{jsxref("RangeError")}}
+  - : Thrown if the time zone name is invalid.
+
+## Examples
+
+### Using withTimeZone()
+
+```js
+const meetingTime = Temporal.ZonedDateTime.from(
+  "2021-08-01T12:00[America/New_York]",
+);
+const meetingTimeInParis = meetingTime.withTimeZone("Europe/Paris");
+console.log(meetingTimeInParis.toString()); // 2021-08-01T18:00:00+02:00[Europe/Paris]
+```
+
+### Replacing the time zone while keeping the same wall-clock time
+
+In the rare case where you want to keep the wall-clock time the same but change the time zone (and result in a different instant), convert it to a {{jsxref("Temporal.PlainDateTime")}} first:
+
+```js
+const meetingTime = Temporal.ZonedDateTime.from(
+  "2021-08-01T12:00[America/New_York]",
+);
+const meetingTimeInParis = meetingTime
+  .toPlainDateTime()
+  .toZonedDateTime("Europe/Paris");
+console.log(meetingTimeInParis.toString()); // 2021-08-01T12:00:00+02:00[Europe/Paris]
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/with", "Temporal.ZonedDateTime.prototype.with()")}}
+- {{jsxref("Temporal/ZonedDateTime/withCalendar", "Temporal.ZonedDateTime.prototype.withCalendar()")}}
+- {{jsxref("Temporal/ZonedDateTime/withPlainTime", "Temporal.ZonedDateTime.prototype.withPlainTime()")}}
+- {{jsxref("Temporal/ZonedDateTime/from", "Temporal.ZonedDateTime.from()")}}
+- {{jsxref("Temporal/ZonedDateTime/timeZoneId", "Temporal.ZonedDateTime.prototype.timeZoneId")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/year/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/year/index.md
new file mode 100644
index 000000000000000..1dbc3b21b070a27
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/year/index.md
@@ -0,0 +1,46 @@
+---
+title: Temporal.ZonedDateTime.prototype.year
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/year
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.year
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`year`** accessor property of {{jsxref("Temporal.ZonedDateTime")}} instances returns an integer representing the number of years of this date relative to the start of a calendar-specific epoch year. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+The set accessor of `year` is `undefined`. You cannot change this property directly. Use the {{jsxref("Temporal/ZonedDateTime/with", "with()")}} method to create a new `Temporal.ZonedDateTime` object with the desired new value.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/year", "Temporal.PlainDate.prototype.year")}}.
+
+## Examples
+
+### Using year
+
+```js
+const dt = Temporal.ZonedDateTime.from("2021-07-01[America/New_York]"); // ISO 8601 calendar
+console.log(dt.year); // 2021
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/with", "Temporal.ZonedDateTime.prototype.with()")}}
+- {{jsxref("Temporal/ZonedDateTime/add", "Temporal.ZonedDateTime.prototype.add()")}}
+- {{jsxref("Temporal/ZonedDateTime/subtract", "Temporal.ZonedDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/ZonedDateTime/era", "Temporal.ZonedDateTime.prototype.era")}}
+- {{jsxref("Temporal/ZonedDateTime/eraYear", "Temporal.ZonedDateTime.prototype.eraYear")}}
+- {{jsxref("Temporal/ZonedDateTime/yearOfWeek", "Temporal.ZonedDateTime.prototype.yearOfWeek")}}
+- {{jsxref("Temporal/ZonedDateTime/month", "Temporal.ZonedDateTime.prototype.month")}}
+- {{jsxref("Temporal/ZonedDateTime/day", "Temporal.ZonedDateTime.prototype.day")}}
+- {{jsxref("Temporal/PlainDate/year", "Temporal.PlainDate.prototype.year")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/yearofweek/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/yearofweek/index.md
new file mode 100644
index 000000000000000..9f61e9a4e107dd0
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/yearofweek/index.md
@@ -0,0 +1,37 @@
+---
+title: Temporal.ZonedDateTime.prototype.yearOfWeek
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/yearOfWeek
+page-type: javascript-instance-accessor-property
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.yearOfWeek
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`yearOfWeek`** accessor property of {{jsxref("Temporal.ZonedDateTime")}} instances returns an integer representing the year to be paired with the {{jsxref("Temporal/ZonedDateTime/weekOfYear", "weekOfYear")}} of this date, or `undefined` if the calendar does not have a well-defined week system. It is [calendar](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#calendars)-dependent.
+
+The set accessor of `yearOfWeek` is `undefined`. You cannot change this property directly.
+
+For general information and more examples, see {{jsxref("Temporal/PlainDate/yearOfWeek", "Temporal.PlainDate.prototype.yearOfWeek")}}.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/with", "Temporal.ZonedDateTime.prototype.with()")}}
+- {{jsxref("Temporal/ZonedDateTime/add", "Temporal.ZonedDateTime.prototype.add()")}}
+- {{jsxref("Temporal/ZonedDateTime/subtract", "Temporal.ZonedDateTime.prototype.subtract()")}}
+- {{jsxref("Temporal/ZonedDateTime/year", "Temporal.ZonedDateTime.prototype.year")}}
+- {{jsxref("Temporal/ZonedDateTime/weekOfYear", "Temporal.ZonedDateTime.prototype.weekOfYear")}}
+- {{jsxref("Temporal/ZonedDateTime/dayOfWeek", "Temporal.ZonedDateTime.prototype.dayOfWeek")}}
+- {{jsxref("Temporal/ZonedDateTime/daysInWeek", "Temporal.ZonedDateTime.prototype.daysInWeek")}}
+- {{jsxref("Temporal/ZonedDateTime/daysInYear", "Temporal.ZonedDateTime.prototype.daysInYear")}}
+- {{jsxref("Temporal/PlainDate/yearOfWeek", "Temporal.PlainDate.prototype.yearOfWeek")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/zoneddatetime/index.md b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/zoneddatetime/index.md
new file mode 100644
index 000000000000000..2403a77052c8afa
--- /dev/null
+++ b/files/en-us/web/javascript/reference/global_objects/temporal/zoneddatetime/zoneddatetime/index.md
@@ -0,0 +1,65 @@
+---
+title: Temporal.ZonedDateTime()
+slug: Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/ZonedDateTime
+page-type: javascript-constructor
+status:
+  - experimental
+browser-compat: javascript.builtins.Temporal.ZonedDateTime.ZonedDateTime
+---
+
+{{JSRef}}{{SeeCompatTable}}
+
+The **`Temporal.ZonedDateTime()`** constructor creates {{jsxref("Temporal.ZonedDateTime")}} objects.
+
+This constructor allows you to create instances by directly supplying the underlying data. Like all other `Temporal` classes, you should usually construct `Temporal.ZonedDateTime` objects using the {{jsxref("Temporal/ZonedDateTime/from", "Temporal.ZonedDateTime.from()")}} static method, which can handle a variety of input types.
+
+## Syntax
+
+```js-nolint
+new Temporal.ZonedDateTime(epochNanoseconds, timeZone)
+new Temporal.ZonedDateTime(epochNanoseconds, timeZone, calendar)
+```
+
+> **Note:** `Temporal.ZonedDateTime()` can only be constructed with [`new`](/en-US/docs/Web/JavaScript/Reference/Operators/new). Attempting to call it without `new` throws a {{jsxref("TypeError")}}.
+
+### Parameters
+
+- `epochNanoseconds`
+  - : A [BigInt](/en-US/docs/Web/JavaScript/Reference/Global_Objects/BigInt) that corresponds to the {{jsxref("Temporal/ZonedDateTime/epochNanoseconds", "epochNanoseconds")}} property.
+- `timeZone`
+  - : A string that corresponds to the {{jsxref("Temporal/ZonedDateTime/timeZoneId", "timeZoneId")}} property. Unlike all other `Temporal` APIs, it must be a valid time zone identifier (either named or offset) as-is, and cannot be a `Temporal.ZonedDateTime` instance or a date-time string.
+- `calendar` {{optional_inline}}
+  - : A string that corresponds to the {{jsxref("Temporal/ZonedDateTime/calendarId", "calendarId")}} property. Defaults to `"iso8601"`.
+
+### Return value
+
+A new `Temporal.ZonedDateTime` object, representing the specific instant specified by the parameters.
+
+### Exceptions
+
+- {{jsxref("TypeError")}}
+  - : Thrown if `timeZone` or `calendar` is not a string.
+- {{jsxref("RangeError")}}
+  - : Thrown if any parameter is not within the valid range.
+
+## Examples
+
+### Using Temporal.ZonedDateTime()
+
+```js
+const zdt = new Temporal.ZonedDateTime(0n, "America/New_York");
+console.log(zdt.toString()); // '1969-12-31T19:00:00-05:00[America/New_York]'
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{jsxref("Temporal.ZonedDateTime")}}
+- {{jsxref("Temporal/ZonedDateTime/from", "Temporal.ZonedDateTime.from()")}}
diff --git a/files/en-us/web/javascript/reference/global_objects/typedarray/find/index.md b/files/en-us/web/javascript/reference/global_objects/typedarray/find/index.md
index 679ad35b2e12161..4674048ba1318d1 100644
--- a/files/en-us/web/javascript/reference/global_objects/typedarray/find/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/typedarray/find/index.md
@@ -42,9 +42,9 @@ See {{jsxref("Array.prototype.find()")}} for more details. This method is not ge
 
 ## Examples
 
-### Find a prime number in a typed array
+### Find the first prime number in a typed array
 
-The following example finds an element in the typed array that is a prime number (or returns {{jsxref("undefined")}} if there is no prime number).
+The following example returns the first element in the typed array that is a prime number, or {{jsxref("undefined")}} if there is no prime number.
 
 ```js
 function isPrime(element, index, array) {
diff --git a/files/en-us/web/javascript/reference/global_objects/typedarray/findindex/index.md b/files/en-us/web/javascript/reference/global_objects/typedarray/findindex/index.md
index 6de911a0f8f6336..3bafcc6f3b0f169 100644
--- a/files/en-us/web/javascript/reference/global_objects/typedarray/findindex/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/typedarray/findindex/index.md
@@ -41,10 +41,9 @@ See {{jsxref("Array.prototype.findIndex()")}} for more details. This method is n
 
 ## Examples
 
-### Find the index of a prime number in a typed array
+### Find the index of the first prime number in a typed array
 
-The following example finds the index of an element in the typed array that is a prime
-number (or returns `-1` if there is no prime number).
+The following example returns the index of the first element in the typed array that is a prime number, or `-1` if there is no prime number.
 
 ```js
 function isPrime(element, index, array) {
diff --git a/files/en-us/web/javascript/reference/global_objects/typedarray/findlast/index.md b/files/en-us/web/javascript/reference/global_objects/typedarray/findlast/index.md
index 08765cb2f6160ed..650548bb177466b 100644
--- a/files/en-us/web/javascript/reference/global_objects/typedarray/findlast/index.md
+++ b/files/en-us/web/javascript/reference/global_objects/typedarray/findlast/index.md
@@ -43,7 +43,7 @@ See {{jsxref("Array.prototype.findLast()")}} for more details. This method is no
 
 ### Find the last prime number in a typed array
 
-The following example returns the value of the last element in the typed array that is a prime number, or {{jsxref("undefined")}} if there is no prime number.
+The following example returns the last element in the typed array that is a prime number, or {{jsxref("undefined")}} if there is no prime number.
 
 ```js
 function isPrime(element) {
diff --git a/files/en-us/web/javascript/reference/index.md b/files/en-us/web/javascript/reference/index.md
index 1819afebd62827f..9d2bb98878bbf87 100644
--- a/files/en-us/web/javascript/reference/index.md
+++ b/files/en-us/web/javascript/reference/index.md
@@ -62,6 +62,7 @@ If you are new to JavaScript, start with the [guide](/en-US/docs/Web/JavaScript/
 - {{jsxref("BigInt")}}
 - {{jsxref("Math")}}
 - {{jsxref("Date")}}
+- {{jsxref("Temporal")}}
 
 ### Text processing
 
diff --git a/files/en-us/web/javascript/reference/operators/instanceof/index.md b/files/en-us/web/javascript/reference/operators/instanceof/index.md
index 90c9a4a6cb7222b..9025ec3445a129e 100644
--- a/files/en-us/web/javascript/reference/operators/instanceof/index.md
+++ b/files/en-us/web/javascript/reference/operators/instanceof/index.md
@@ -143,16 +143,16 @@ stringObject instanceof Object; // true
 stringObject instanceof Date; // false
 ```
 
-### Using instanceof with Date
+### Using instanceof with Map
 
-The following example shows the behavior of `instanceof` with `Date` objects.
+The following example shows the behavior of `instanceof` with `Map` objects.
 
 ```js
-const myDate = new Date();
+const myMap = new Map();
 
-myDate instanceof Date; // true
-myDate instanceof Object; // true
-myDate instanceof String; // false
+myMap instanceof Map; // true
+myMap instanceof Object; // true
+myMap instanceof String; // false
 ```
 
 ### Objects created using Object.create()
diff --git a/files/en-us/web/javascript/reference/operators/object_initializer/index.md b/files/en-us/web/javascript/reference/operators/object_initializer/index.md
index c61b8e889601bdd..15d2411aa70252e 100644
--- a/files/en-us/web/javascript/reference/operators/object_initializer/index.md
+++ b/files/en-us/web/javascript/reference/operators/object_initializer/index.md
@@ -47,7 +47,7 @@ An object initializer is an expression that describes the initialization of an {
 The object literal syntax is not the same as the **J**ava**S**cript **O**bject **N**otation ([JSON](/en-US/docs/Glossary/JSON)). Although they look similar, there are differences between them:
 
 - JSON _only_ permits property definition using the `"property": value` syntax. The property name must be double-quoted, and the definition cannot be a shorthand. Computed property names are not allowed either.
-- JSON object property values can only be strings, numbers, `true`, `false`, `null`, arrays, or another JSON object. This means JSON cannot express methods or non-plain objects like [`Date`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date) or [`RegExp`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp).
+- JSON object property values can only be strings, numbers, `true`, `false`, `null`, arrays, or another JSON object. This means JSON cannot express methods or non-plain objects like [`Map`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map) or [`RegExp`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp).
 - In JSON, `"__proto__"` is a normal property key. In an object literal, it [sets the object's prototype](#prototype_setter).
 
 JSON is a _strict subset_ of the object literal syntax, meaning that every valid JSON text can be parsed as an object literal, and would likely not cause syntax errors. The only exception is that the object literal syntax prohibits duplicate `__proto__` keys, which does not apply to [`JSON.parse()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/parse). The latter treats `__proto__` like a normal property and takes the last occurrence as the property's value. The only time when the object value they represent (a.k.a. their semantic) differ is also when the source contains the `__proto__` key — for object literals, it sets the object's prototype; for JSON, it's a normal property.
diff --git a/files/en-us/web/javascript/reference/operators/yield_star_/index.md b/files/en-us/web/javascript/reference/operators/yield_star_/index.md
index af632fe1b77846a..7b934f3eb5771b6 100644
--- a/files/en-us/web/javascript/reference/operators/yield_star_/index.md
+++ b/files/en-us/web/javascript/reference/operators/yield_star_/index.md
@@ -132,7 +132,7 @@ async function* g3() {
   yield* g2();
 }
 
-const gen = g4();
+const gen = g3();
 
 console.log(await gen.next()); // {value: "foo", done: false}
 console.log(await gen.next()); // {value: "bar", done: false}
diff --git a/files/en-us/web/javascript/reference/strict_mode/index.md b/files/en-us/web/javascript/reference/strict_mode/index.md
index 3e0899e701e14f1..1a6d3470a228761 100644
--- a/files/en-us/web/javascript/reference/strict_mode/index.md
+++ b/files/en-us/web/javascript/reference/strict_mode/index.md
@@ -10,7 +10,7 @@ spec-urls: https://tc39.es/ecma262/multipage/strict-mode-of-ecmascript.html
 > [!NOTE]
 > Sometimes you'll see the default, non-strict mode referred to as _[sloppy mode](/en-US/docs/Glossary/Sloppy_mode)_. This isn't an official term, but be aware of it, just in case.
 
-JavaScript's strict mode is a way to _opt in_ to a restricted variant of JavaScript, thereby implicitly opting-out of "[sloppy mode](/en-US/docs/Glossary/Sloppy_mode)". Strict mode isn't just a subset: it _intentionally_ has different semantics from normal code. Browsers not supporting strict mode will run strict mode code with different behavior from browsers that do, so don't rely on strict mode without feature-testing for support for the relevant aspects of strict mode. Strict mode code and non-strict mode code can coexist, so scripts can opt into strict mode incrementally.
+JavaScript's strict mode is a way to _opt in_ to a restricted variant of JavaScript, thereby implicitly opting-out of "[sloppy mode](/en-US/docs/Glossary/Sloppy_mode)". Strict mode isn't just a subset: it _intentionally_ has different semantics from normal code. Strict mode code and non-strict mode code can coexist, so scripts can opt into strict mode incrementally.
 
 Strict mode makes several changes to normal JavaScript semantics:
 
diff --git a/files/en-us/web/javascript/reference/template_literals/index.md b/files/en-us/web/javascript/reference/template_literals/index.md
index 0334aa5ac70ebea..0a7955eb8692cc2 100644
--- a/files/en-us/web/javascript/reference/template_literals/index.md
+++ b/files/en-us/web/javascript/reference/template_literals/index.md
@@ -366,7 +366,7 @@ const bad = `bad escape sequence: \unicode`;
 
 ## See also
 
-- [Text formatting](/en-US/docs/Web/JavaScript/Guide/Text_formatting) guide
+- [Numbers and strings](/en-US/docs/Web/JavaScript/Guide/Numbers_and_strings) guide
 - {{jsxref("String")}}
 - {{jsxref("String.raw()")}}
 - [Lexical grammar](/en-US/docs/Web/JavaScript/Reference/Lexical_grammar)
diff --git a/files/en-us/web/manifest/index.md b/files/en-us/web/manifest/index.md
index 7148fa0bbc2cce5..b70839ecf8d827b 100644
--- a/files/en-us/web/manifest/index.md
+++ b/files/en-us/web/manifest/index.md
@@ -22,7 +22,7 @@ All members are optional in the specification, but some applications require som
 {{ListSubpages("/en-US/docs/Web/Manifest")}}
 
 > [!NOTE]
-> The `dir`, `lang`, `iarc_rating_id`, and `note_taking` members are not implemented.
+> The `dir`, `lang`, and `iarc_rating_id` members are not implemented.
 
 ## Example manifest
 
diff --git a/files/en-us/web/manifest/note_taking/index.md b/files/en-us/web/manifest/note_taking/index.md
index d756bbb6dc0438a..46da812861458f6 100644
--- a/files/en-us/web/manifest/note_taking/index.md
+++ b/files/en-us/web/manifest/note_taking/index.md
@@ -15,7 +15,7 @@ The `note_taking` member identifies a web app as a note-taking app and defines r
 
 An object, which may contain the following values:
 
-- `new_note_url`
+- `new_note_url` {{experimental_inline}}
 
   - : A string representing the URL the developer would prefer the user agent to load when the user wants to take a new note via the web app. This value is a hint, and different implementations may choose to ignore it or provide it as a choice in appropriate places. The `new_note_url` is parsed with the app's manifest URL as its base URL and is ignored if not within the [scope](/en-US/docs/Web/Manifest/scope) of the manifest.
 
diff --git a/files/en-us/web/security/mixed_content/index.md b/files/en-us/web/security/mixed_content/index.md
index 91df10aa7eafac4..cea6781e0666ed5 100644
--- a/files/en-us/web/security/mixed_content/index.md
+++ b/files/en-us/web/security/mixed_content/index.md
@@ -129,7 +129,7 @@ The screenshot below shows the console warning when an image is upgraded on Fire
 ![Screen shot of the web console displaying upgrade warning for mixed content image.](mixed_content_console_upgradable.png)
 
 On browser versions that still display "optionally blockable" content, an icon is used to indicate that there is mixed content in the displayed content, along with a console warning.
-The screenshot below shows the icon and console warning for Firebox starting supporting upgradable mixed-content.
+The screenshot below shows the icon and console warning for Firefox starting supporting upgradable mixed-content.
 
 ![Screen shot of the web console displaying display warning for mixed content image.](mixed_content_console_displayed.png)
 
diff --git a/files/en-us/web/security/practical_implementation_guides/cookies/index.md b/files/en-us/web/security/practical_implementation_guides/cookies/index.md
index 26722eda74c9cc9..e7aa379cee4efa8 100644
--- a/files/en-us/web/security/practical_implementation_guides/cookies/index.md
+++ b/files/en-us/web/security/practical_implementation_guides/cookies/index.md
@@ -25,7 +25,7 @@ To minimize the scope for cookie vulnerabilities on your site, limit access to c
 - `HttpOnly`
   - : Cookies that don't require access from JavaScript should have the `HttpOnly` directive set to block access, such as from {{domxref("Document.cookie")}}. It is particularly important that session identifiers don't have JavaScript access, to help prevent attacks such as CSRF.
 - `Expires` and `Max-Age`
-  - : Cookies should expire as soon as they are no longer needed. Session identifiers in particular should expire as quickly as possible. `Expires` is preferred unless you need to support IE < 8, in which case use `Max-Age`.
+  - : Cookies should expire as soon as they are no longer needed. Session identifiers in particular should expire as quickly as possible.
     - `Expires`: Sets an absolute expiration date for a given cookie.
     - `Max-Age`: Sets a relative expiration date for a given cookie.
       > **Note:** `Expires` has been available for longer than `Max-Age`; however, `Max-Age` is less error-prone, and takes precedence when both are set. The rationale behind this is that when you set an `Expires` date and time, they're relative to the client on which the cookie is being set. If the server is set to a different time, this could cause errors.
diff --git a/files/en-us/web/svg/attribute/alignment-baseline/index.md b/files/en-us/web/svg/attribute/alignment-baseline/index.md
index 45528d508f084b1..1bd78409fe9c76d 100644
--- a/files/en-us/web/svg/attribute/alignment-baseline/index.md
+++ b/files/en-us/web/svg/attribute/alignment-baseline/index.md
@@ -48,7 +48,7 @@ You can use this attribute with the following SVG elements:
 - `auto` {{deprecated_inline}}
   - : The value is the dominant-baseline of the script to which the character belongs - i.e., use the dominant-baseline of the parent.
 - `baseline`
-  - : Uses the {{Glossary("dominant baseline")}} choice of the parent. Matches the box's corresponding {{Glossary("baseline/typography", "baseline")}} to that of its parent.
+  - : Uses the {{svgattr("dominant-baseline")}} choice of the parent. Matches the box's corresponding {{Glossary("baseline/typography", "baseline")}} to that of its parent.
 - `before-edge` {{deprecated_inline}}
   - : The alignment-point of the object being aligned is aligned with the "before-edge" baseline of the parent text content element.
 - `text-bottom`
@@ -145,4 +145,4 @@ For object alignment in other elements (such as {{SVGElement("text")}}), see {{S
 
 ## See also
 
-- [CSS baseline alignment](/en-US/docs/Web/CSS/CSS_box_alignment#baseline_alignment)
+- [CSS baseline alignment](/en-US/docs/Web/CSS/CSS_box_alignment/Box_alignment#baseline_alignment)
diff --git a/files/en-us/web/svg/attribute/filter/index.md b/files/en-us/web/svg/attribute/filter/index.md
index 5538eb7268da536..8611b53c68697bd 100644
--- a/files/en-us/web/svg/attribute/filter/index.md
+++ b/files/en-us/web/svg/attribute/filter/index.md
@@ -49,7 +49,7 @@ svg {
           title="Single bar: exactly one of the entities must be present"
           >|</a
         >
-        <code>&#x3C;filter-function-list></code>
+        <code>&#x3C;filter-value-list></code>
       </td>
     </tr>
     <tr>
diff --git a/files/en-us/web/svg/element/index.md b/files/en-us/web/svg/element/index.md
index 245c4fc0b56cf57..334e4463c2679d8 100644
--- a/files/en-us/web/svg/element/index.md
+++ b/files/en-us/web/svg/element/index.md
@@ -237,5 +237,3 @@ SVG drawings and images are created using a wide array of elements which are ded
 - [SVG attribute reference](/en-US/docs/Web/SVG/Attribute)
 - [SVG Tutorial](/en-US/docs/Web/SVG/Tutorial)
 - [SVG interface reference](/en-US/docs/Web/API/Document_Object_Model#svg_dom)
-
-{{SVGRef}}
diff --git a/files/jsondata/InterfaceData.json b/files/jsondata/InterfaceData.json
index afe3d992e83f44b..7b141388609d7f8 100644
--- a/files/jsondata/InterfaceData.json
+++ b/files/jsondata/InterfaceData.json
@@ -552,6 +552,14 @@
       "inh": "CSSRule",
       "impl": []
     },
+    "CSSFunctionDeclarations": {
+      "inh": "CSSRule",
+      "impl": []
+    },
+    "CSSFunctionDescriptors": {
+      "inh": "CSSStyleDeclaration",
+      "impl": []
+    },
     "CSSFunctionRule": {
       "inh": "CSSGroupingRule",
       "impl": []
@@ -3072,6 +3080,26 @@
       "inh": "",
       "impl": []
     },
+    "SharedStorageAppendMethod": {
+      "inh": "SharedStorageModifierMethod",
+      "impl": []
+    },
+    "SharedStorageClearMethod": {
+      "inh": "SharedStorageModifierMethod",
+      "impl": []
+    },
+    "SharedStorageDeleteMethod": {
+      "inh": "SharedStorageModifierMethod",
+      "impl": []
+    },
+    "SharedStorageModifierMethod": {
+      "inh": "",
+      "impl": []
+    },
+    "SharedStorageSetMethod": {
+      "inh": "SharedStorageModifierMethod",
+      "impl": []
+    },
     "SharedStorageWorklet": {
       "inh": "Worklet",
       "impl": []
diff --git a/files/sidebars/cssref.yaml b/files/sidebars/cssref.yaml
index 3f2b20e1f819b13..44c3884c2cbadbe 100644
--- a/files/sidebars/cssref.yaml
+++ b/files/sidebars/cssref.yaml
@@ -97,6 +97,7 @@ sidebar:
     title: Functions
     tags: css-function
     details: closed
+    depth: 2
   - type: listSubPages
     path: /Web/CSS
     title: Types
diff --git a/files/sidebars/glossarysidebar.yaml b/files/sidebars/glossarysidebar.yaml
index 0b0116f6d3563da..8702f6d057c4597 100644
--- a/files/sidebars/glossarysidebar.yaml
+++ b/files/sidebars/glossarysidebar.yaml
@@ -6,3 +6,5 @@ sidebar:
     title: Glossary
   - type: listSubPages
     path: /Glossary
+    depth: 2
+    nested: true
diff --git a/files/sidebars/jssidebar.yaml b/files/sidebars/jssidebar.yaml
index 50717b68e334031..9a03d52ce6187fb 100644
--- a/files/sidebars/jssidebar.yaml
+++ b/files/sidebars/jssidebar.yaml
@@ -30,10 +30,10 @@ sidebar:
         title: Guide_Functions
       - link: /Web/JavaScript/Guide/Expressions_and_operators
         title: Guide_Expressions
-      - link: /Web/JavaScript/Guide/Numbers_and_dates
+      - link: /Web/JavaScript/Guide/Numbers_and_strings
         title: Guide_Numbers
-      - link: /Web/JavaScript/Guide/Text_formatting
-        title: Guide_Text
+      - link: /Web/JavaScript/Guide/Representing_dates_times
+        title: Guide_Dates
       - link: /Web/JavaScript/Guide/Regular_expressions
         title: Guide_RegExp
       - link: /Web/JavaScript/Guide/Indexed_collections
@@ -50,6 +50,8 @@ sidebar:
         title: Guide_Typed_arrays
       - link: /Web/JavaScript/Guide/Iterators_and_generators
         title: Guide_Iterators_generators
+      - link: /Web/JavaScript/Guide/Internationalization
+        title: Guide_Internationalization
       - link: /Web/JavaScript/Guide/Meta_programming
         title: Guide_Meta
       - link: /Web/JavaScript/Guide/Modules
@@ -148,8 +150,8 @@ l10n:
     Guide_Loops: Schleifen und Iteration
     Guide_Functions: Funktionen
     Guide_Expressions: Ausdrücke und Operatoren
-    Guide_Numbers: Zahlen und Daten
-    Guide_Text: Textformatierung
+    Guide_Numbers: Numbers and strings
+    Guide_Dates: Representing dates & times
     Guide_RegExp: Reguläre Ausdrücke
     Guide_Indexed_collections: Indexierte Sammlungen
     Guide_keyed_collections: Gekennzeichnete Sammlungen
@@ -158,6 +160,7 @@ l10n:
     Guide_Promises: Verwendung von Promises
     Guide_Typed_arrays: Typisierte Arrays in JavaScript
     Guide_Iterators_generators: Iteratoren und Generatoren
+    Guide_Internationalization: Internationalization
     Guide_Meta: Metaprogrammierung
     Guide_Modules: JavaScript-Module
     Intermediate: Mittelstufe
@@ -194,8 +197,8 @@ l10n:
     Guide_Loops: Loops and iteration
     Guide_Functions: Functions
     Guide_Expressions: Expressions and operators
-    Guide_Numbers: Numbers and dates
-    Guide_Text: Text formatting
+    Guide_Numbers: Numbers and strings
+    Guide_Dates: Representing dates & times
     Guide_RegExp: Regular expressions
     Guide_Indexed_collections: Indexed collections
     Guide_keyed_collections: Keyed collections
@@ -204,6 +207,7 @@ l10n:
     Guide_Promises: Using promises
     Guide_Typed_arrays: JavaScript typed arrays
     Guide_Iterators_generators: Iterators and generators
+    Guide_Internationalization: Internationalization
     Guide_Meta: Meta programming
     Guide_Modules: JavaScript modules
     Beginners: Beginner's tutorials
@@ -246,8 +250,8 @@ l10n:
     Guide_Loops: Циклы и итерации
     Guide_Functions: Функции
     Guide_Expressions: Выражения и операторы
-    Guide_Numbers: Числа и даты
-    Guide_Text: Форматирование текста
+    Guide_Numbers: Numbers and strings
+    Guide_Dates: Representing dates & times
     Guide_RegExp: Регулярные выражения
     Guide_Indexed_collections: Упорядоченные наборы данных
     Guide_keyed_collections: Коллекции
@@ -256,6 +260,7 @@ l10n:
     Guide_Promises: Использование промисов
     Guide_Typed_arrays: Типизированные массивы JavaScript
     Guide_Iterators_generators: Итераторы и генераторы
+    Guide_Internationalization: Internationalization
     Guide_Meta: Метапрограммирование
     Guide_Modules: Модули JavaScript
     Intermediate: Средние
@@ -292,8 +297,8 @@ l10n:
     Guide_Loops: Boucles et itération
     Guide_Functions: Fonctions
     Guide_Expressions: Expressions et opérateurs
-    Guide_Numbers: Nombres et dates
-    Guide_Text: Formatage du texte
+    Guide_Numbers: Numbers and strings
+    Guide_Dates: Representing dates & times
     Guide_RegExp: Expressions rationnelles
     Guide_Indexed_collections: Collections indexées
     Guide_keyed_collections: Collections avec clés
@@ -302,6 +307,7 @@ l10n:
     Guide_Promises: Utiliser les promesses
     Guide_Typed_arrays: Tableaux typés en JavaScript
     Guide_Iterators_generators: Itérateurs et générateurs
+    Guide_Internationalization: Internationalization
     Guide_Meta: Métaprogrammation
     Guide_Modules: Modules JavaScript
     Intermediate: Intermédiaire
@@ -338,8 +344,8 @@ l10n:
     Guide_Loops: 循环与迭代
     Guide_Functions: 函数
     Guide_Expressions: 表达式与运算符
-    Guide_Numbers: 数字和日期
-    Guide_Text: 文本格式化
+    Guide_Numbers: 数字与字符串
+    Guide_Dates: 表达日期与时间
     Guide_RegExp: 正则表达式
     Guide_Indexed_collections: 索引集合类
     Guide_keyed_collections: 带键的集合
@@ -348,6 +354,7 @@ l10n:
     Guide_Promises: 使用 Promise
     Guide_Typed_arrays: JavaScript 类型化数组
     Guide_Iterators_generators: 迭代器和生成器
+    Guide_Internationalization: 国际化
     Guide_Meta: 元编程
     Guide_Modules: JavaScript 模块
     Intermediate: 中级
@@ -384,8 +391,8 @@ l10n:
     Guide_Loops: ループとイテレーター
     Guide_Functions: 関数
     Guide_Expressions: 式と演算子
-    Guide_Numbers: 数と日付
-    Guide_Text: テキスト処理
+    Guide_Numbers: Numbers and strings
+    Guide_Dates: Representing dates & times
     Guide_RegExp: 正規表現
     Guide_Indexed_collections: インデックス付きコレクション
     Guide_keyed_collections: キー付きコレクション
@@ -394,6 +401,7 @@ l10n:
     Guide_Promises: プロミスの使用
     Guide_Typed_arrays: JavaScript 型付き配列
     Guide_Iterators_generators: イテレーターとジェネレーター
+    Guide_Internationalization: Internationalization
     Guide_Meta: メタプログラミング
     Guide_Modules: JavaScript モジュール
     Intermediate: 中級編
@@ -430,8 +438,8 @@ l10n:
     Guide_Loops: 루프와 반복
     Guide_Functions: 함수
     Guide_Expressions: 표현식과 연산자
-    Guide_Numbers: 숫자와 날짜
-    Guide_Text: 텍스트 서식
+    Guide_Numbers: Numbers and strings
+    Guide_Dates: Representing dates & times
     Guide_RegExp: 정규 표현식
     Guide_Indexed_collections: index 기반의 컬렉션
     Guide_keyed_collections: key 기반의 컬렉션
@@ -440,6 +448,7 @@ l10n:
     Guide_Promises: promise 사용하기
     Guide_Typed_arrays: JavaScript 형식화 배열
     Guide_Iterators_generators: 반복기와 생성기
+    Guide_Internationalization: Internationalization
     Guide_Meta: 메타 프로그래밍
     Guide_Modules: JavaScript 모듈
     Intermediate: 중급서
@@ -476,8 +485,8 @@ l10n:
     Guide_Loops: Repetição e iteração
     Guide_Functions: Funções
     Guide_Expressions: Expressões e operadores
-    Guide_Numbers: Números e datas
-    Guide_Text: Formatação de texto
+    Guide_Numbers: Numbers and strings
+    Guide_Dates: Representing dates & times
     Guide_RegExp: Expressões Regulares
     Guide_Indexed_collections: Coleções indexadas
     Guide_keyed_collections: Coleções com chave (chave-valor)
@@ -486,6 +495,7 @@ l10n:
     Guide_Promises: Usando "promises"
     Guide_Typed_arrays: Arranjos tipados em JavaScript
     Guide_Iterators_generators: Iteradores e geradores
+    Guide_Internationalization: Internationalization
     Guide_Meta: Metaprogramação
     Guide_Modules: JavaScript modules
     Intermediate: Intermediário
diff --git a/files/sidebars/learnsidebar.yaml b/files/sidebars/learnsidebar.yaml
index 6319fc35a535d88..ced4eafb0007c38 100644
--- a/files/sidebars/learnsidebar.yaml
+++ b/files/sidebars/learnsidebar.yaml
@@ -187,7 +187,6 @@ sidebar:
     details: closed
     children:
       - /Learn_web_development/Extensions/Async_JS/Introducing
-      - /Learn_web_development/Extensions/Client-side_APIs/Video_and_audio_APIs
       - /Learn_web_development/Extensions/Async_JS/Promises
       - /Learn_web_development/Extensions/Async_JS/Implementing_a_promise-based_API
       - /Learn_web_development/Extensions/Async_JS/Introducing_workers
diff --git a/package.json b/package.json
index 104d319270389c6..6401b605bc7e680 100644
--- a/package.json
+++ b/package.json
@@ -42,7 +42,7 @@
   "dependencies": {
     "@apideck/better-ajv-errors": "^0.3.6",
     "@caporal/core": "^2.0.7",
-    "@mdn/yari": "4.1.2",
+    "@mdn/yari": "4.2.0",
     "ajv": "^8.17.1",
     "ajv-formats": "^3.0.1",
     "async": "^3.2.6",
@@ -50,12 +50,12 @@
     "cli-progress": "^3.12.0",
     "cross-env": "7.0.3",
     "env-cmd": "10.1.0",
-    "fdir": "^6.4.2",
+    "fdir": "^6.4.3",
     "gray-matter": "^4.0.3",
     "husky": "9.1.7",
     "js-yaml": "^4.1.0",
-    "lint-staged": "15.3.0",
-    "markdownlint-cli2": "0.17.1",
+    "lint-staged": "15.4.2",
+    "markdownlint-cli2": "0.17.2",
     "markdownlint-rule-search-replace": "1.2.0",
     "prettier": "3.4.2"
   },
diff --git a/yarn.lock b/yarn.lock
index 43636f2f442f1f1..2505da4fab9bf95 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -469,29 +469,29 @@
     lodash.isundefined "^3.0.1"
     lodash.uniq "^4.5.0"
 
-"@inquirer/checkbox@^4.0.4":
-  version "4.0.4"
-  resolved "https://registry.yarnpkg.com/@inquirer/checkbox/-/checkbox-4.0.4.tgz#e7335f9c23f4100f789a8fceb26417c9a74a6dee"
-  integrity sha512-fYAKCAcGNMdfjL6hZTRUwkIByQ8EIZCXKrIQZH7XjADnN/xvRUhj8UdBbpC4zoUzvChhkSC/zRKaP/tDs3dZpg==
+"@inquirer/checkbox@^4.0.6":
+  version "4.0.6"
+  resolved "https://registry.yarnpkg.com/@inquirer/checkbox/-/checkbox-4.0.6.tgz#e71401a7e1900332f17ed68c172a89fe20225f49"
+  integrity sha512-PgP35JfmGjHU0LSXOyRew0zHuA9N6OJwOlos1fZ20b7j8ISeAdib3L+n0jIxBtX958UeEpte6xhG/gxJ5iUqMw==
   dependencies:
-    "@inquirer/core" "^10.1.2"
+    "@inquirer/core" "^10.1.4"
     "@inquirer/figures" "^1.0.9"
     "@inquirer/type" "^3.0.2"
     ansi-escapes "^4.3.2"
     yoctocolors-cjs "^2.1.2"
 
-"@inquirer/confirm@^5.1.1":
-  version "5.1.1"
-  resolved "https://registry.yarnpkg.com/@inquirer/confirm/-/confirm-5.1.1.tgz#18385064b8275eb79fdba505ce527801804eea04"
-  integrity sha512-vVLSbGci+IKQvDOtzpPTCOiEJCNidHcAq9JYVoWTW0svb5FiwSLotkM+JXNXejfjnzVYV9n0DTBythl9+XgTxg==
+"@inquirer/confirm@^5.1.3":
+  version "5.1.3"
+  resolved "https://registry.yarnpkg.com/@inquirer/confirm/-/confirm-5.1.3.tgz#c1ad57663f54758981811ccb86f823072ddf5c1a"
+  integrity sha512-fuF9laMmHoOgWapF9h9hv6opA5WvmGFHsTYGCmuFxcghIhEhb3dN0CdQR4BUMqa2H506NCj8cGX4jwMsE4t6dA==
   dependencies:
-    "@inquirer/core" "^10.1.2"
+    "@inquirer/core" "^10.1.4"
     "@inquirer/type" "^3.0.2"
 
-"@inquirer/core@^10.1.2":
-  version "10.1.2"
-  resolved "https://registry.yarnpkg.com/@inquirer/core/-/core-10.1.2.tgz#a9c5b9ed814a636e99b5c0a8ca4f1626d99fd75d"
-  integrity sha512-bHd96F3ezHg1mf/J0Rb4CV8ndCN0v28kUlrHqP7+ECm1C/A+paB7Xh2lbMk6x+kweQC+rZOxM/YeKikzxco8bQ==
+"@inquirer/core@^10.1.4":
+  version "10.1.4"
+  resolved "https://registry.yarnpkg.com/@inquirer/core/-/core-10.1.4.tgz#02394e68d894021935caca0d10fc68fd4f3a3ead"
+  integrity sha512-5y4/PUJVnRb4bwWY67KLdebWOhOc7xj5IP2J80oWXa64mVag24rwQ1VAdnj7/eDY/odhguW0zQ1Mp1pj6fO/2w==
   dependencies:
     "@inquirer/figures" "^1.0.9"
     "@inquirer/type" "^3.0.2"
@@ -503,21 +503,21 @@
     wrap-ansi "^6.2.0"
     yoctocolors-cjs "^2.1.2"
 
-"@inquirer/editor@^4.2.1":
-  version "4.2.1"
-  resolved "https://registry.yarnpkg.com/@inquirer/editor/-/editor-4.2.1.tgz#9887e95aa28a52eb20e9e08d85cb3698ef404601"
-  integrity sha512-xn9aDaiP6nFa432i68JCaL302FyL6y/6EG97nAtfIPnWZ+mWPgCMLGc4XZ2QQMsZtu9q3Jd5AzBPjXh10aX9kA==
+"@inquirer/editor@^4.2.3":
+  version "4.2.3"
+  resolved "https://registry.yarnpkg.com/@inquirer/editor/-/editor-4.2.3.tgz#0858adcd07d9607b0614778eaa5ce8a83871c367"
+  integrity sha512-S9KnIOJuTZpb9upeRSBBhoDZv7aSV3pG9TECrBj0f+ZsFwccz886hzKBrChGrXMJwd4NKY+pOA9Vy72uqnd6Eg==
   dependencies:
-    "@inquirer/core" "^10.1.2"
+    "@inquirer/core" "^10.1.4"
     "@inquirer/type" "^3.0.2"
     external-editor "^3.1.0"
 
-"@inquirer/expand@^4.0.4":
-  version "4.0.4"
-  resolved "https://registry.yarnpkg.com/@inquirer/expand/-/expand-4.0.4.tgz#e3b052835e48fd4ebcf71813b7eae8b03c729d1b"
-  integrity sha512-GYocr+BPyxKPxQ4UZyNMqZFSGKScSUc0Vk17II3J+0bDcgGsQm0KYQNooN1Q5iBfXsy3x/VWmHGh20QnzsaHwg==
+"@inquirer/expand@^4.0.6":
+  version "4.0.6"
+  resolved "https://registry.yarnpkg.com/@inquirer/expand/-/expand-4.0.6.tgz#8676e6049c6114fb306df23358375bd84fa1c92c"
+  integrity sha512-TRTfi1mv1GeIZGyi9PQmvAaH65ZlG4/FACq6wSzs7Vvf1z5dnNWsAAXBjWMHt76l+1hUY8teIqJFrWBk5N6gsg==
   dependencies:
-    "@inquirer/core" "^10.1.2"
+    "@inquirer/core" "^10.1.4"
     "@inquirer/type" "^3.0.2"
     yoctocolors-cjs "^2.1.2"
 
@@ -526,72 +526,72 @@
   resolved "https://registry.yarnpkg.com/@inquirer/figures/-/figures-1.0.9.tgz#9d8128f8274cde4ca009ca8547337cab3f37a4a3"
   integrity sha512-BXvGj0ehzrngHTPTDqUoDT3NXL8U0RxUk2zJm2A66RhCEIWdtU1v6GuUqNAgArW4PQ9CinqIWyHdQgdwOj06zQ==
 
-"@inquirer/input@^4.1.1":
-  version "4.1.1"
-  resolved "https://registry.yarnpkg.com/@inquirer/input/-/input-4.1.1.tgz#aea2e463087c6aae57b9801e1ae5648f50d0d22e"
-  integrity sha512-nAXAHQndZcXB+7CyjIW3XuQZZHbQQ0q8LX6miY6bqAWwDzNa9JUioDBYrFmOUNIsuF08o1WT/m2gbBXvBhYVxg==
+"@inquirer/input@^4.1.3":
+  version "4.1.3"
+  resolved "https://registry.yarnpkg.com/@inquirer/input/-/input-4.1.3.tgz#fa0ea9a392b2ec4ddd763c504d0b0c8839a48fe2"
+  integrity sha512-zeo++6f7hxaEe7OjtMzdGZPHiawsfmCZxWB9X1NpmYgbeoyerIbWemvlBxxl+sQIlHC0WuSAG19ibMq3gbhaqQ==
   dependencies:
-    "@inquirer/core" "^10.1.2"
+    "@inquirer/core" "^10.1.4"
     "@inquirer/type" "^3.0.2"
 
-"@inquirer/number@^3.0.4":
-  version "3.0.4"
-  resolved "https://registry.yarnpkg.com/@inquirer/number/-/number-3.0.4.tgz#090dcac6886d0cddc255f6624b61fb4461747fee"
-  integrity sha512-DX7a6IXRPU0j8kr2ovf+QaaDiIf+zEKaZVzCWdLOTk7XigqSXvoh4cul7x68xp54WTQrgSnW7P1WBJDbyY3GhA==
+"@inquirer/number@^3.0.6":
+  version "3.0.6"
+  resolved "https://registry.yarnpkg.com/@inquirer/number/-/number-3.0.6.tgz#19bba46725df194bdd907762cf432a37e053b300"
+  integrity sha512-xO07lftUHk1rs1gR0KbqB+LJPhkUNkyzV/KhH+937hdkMazmAYHLm1OIrNKpPelppeV1FgWrgFDjdUD8mM+XUg==
   dependencies:
-    "@inquirer/core" "^10.1.2"
+    "@inquirer/core" "^10.1.4"
     "@inquirer/type" "^3.0.2"
 
-"@inquirer/password@^4.0.4":
-  version "4.0.4"
-  resolved "https://registry.yarnpkg.com/@inquirer/password/-/password-4.0.4.tgz#77891ae3ed5736607e6e942993ac40ca00411a2c"
-  integrity sha512-wiliQOWdjM8FnBmdIHtQV2Ca3S1+tMBUerhyjkRCv1g+4jSvEweGu9GCcvVEgKDhTBT15nrxvk5/bVrGUqSs1w==
+"@inquirer/password@^4.0.6":
+  version "4.0.6"
+  resolved "https://registry.yarnpkg.com/@inquirer/password/-/password-4.0.6.tgz#4bbee12fe7cd1d37435401098c296ddc4586861b"
+  integrity sha512-QLF0HmMpHZPPMp10WGXh6F+ZPvzWE7LX6rNoccdktv/Rov0B+0f+eyXkAcgqy5cH9V+WSpbLxu2lo3ysEVK91w==
   dependencies:
-    "@inquirer/core" "^10.1.2"
+    "@inquirer/core" "^10.1.4"
     "@inquirer/type" "^3.0.2"
     ansi-escapes "^4.3.2"
 
-"@inquirer/prompts@^7.2.1":
-  version "7.2.1"
-  resolved "https://registry.yarnpkg.com/@inquirer/prompts/-/prompts-7.2.1.tgz#f00fbcf06998a07faebc10741efa289384529950"
-  integrity sha512-v2JSGri6/HXSfoGIwuKEn8sNCQK6nsB2BNpy2lSX6QH9bsECrMv93QHnj5+f+1ZWpF/VNioIV2B/PDox8EvGuQ==
-  dependencies:
-    "@inquirer/checkbox" "^4.0.4"
-    "@inquirer/confirm" "^5.1.1"
-    "@inquirer/editor" "^4.2.1"
-    "@inquirer/expand" "^4.0.4"
-    "@inquirer/input" "^4.1.1"
-    "@inquirer/number" "^3.0.4"
-    "@inquirer/password" "^4.0.4"
-    "@inquirer/rawlist" "^4.0.4"
-    "@inquirer/search" "^3.0.4"
-    "@inquirer/select" "^4.0.4"
-
-"@inquirer/rawlist@^4.0.4":
-  version "4.0.4"
-  resolved "https://registry.yarnpkg.com/@inquirer/rawlist/-/rawlist-4.0.4.tgz#d10bbd6c529cd468d3d764c19de21334a01fa6d9"
-  integrity sha512-IsVN2EZdNHsmFdKWx9HaXb8T/s3FlR/U1QPt9dwbSyPtjFbMTlW9CRFvnn0bm/QIsrMRD2oMZqrQpSWPQVbXXg==
+"@inquirer/prompts@^7.2.3":
+  version "7.2.3"
+  resolved "https://registry.yarnpkg.com/@inquirer/prompts/-/prompts-7.2.3.tgz#8a0d7cb5310d429bf815d25bbff108375fc6315b"
+  integrity sha512-hzfnm3uOoDySDXfDNOm9usOuYIaQvTgKp/13l1uJoe6UNY+Zpcn2RYt0jXz3yA+yemGHvDOxVzqWl3S5sQq53Q==
+  dependencies:
+    "@inquirer/checkbox" "^4.0.6"
+    "@inquirer/confirm" "^5.1.3"
+    "@inquirer/editor" "^4.2.3"
+    "@inquirer/expand" "^4.0.6"
+    "@inquirer/input" "^4.1.3"
+    "@inquirer/number" "^3.0.6"
+    "@inquirer/password" "^4.0.6"
+    "@inquirer/rawlist" "^4.0.6"
+    "@inquirer/search" "^3.0.6"
+    "@inquirer/select" "^4.0.6"
+
+"@inquirer/rawlist@^4.0.6":
+  version "4.0.6"
+  resolved "https://registry.yarnpkg.com/@inquirer/rawlist/-/rawlist-4.0.6.tgz#b55d5828d850f07bc6792bbce3b2a963e33b3ef5"
+  integrity sha512-QoE4s1SsIPx27FO4L1b1mUjVcoHm1pWE/oCmm4z/Hl+V1Aw5IXl8FYYzGmfXaBT0l/sWr49XmNSiq7kg3Kd/Lg==
   dependencies:
-    "@inquirer/core" "^10.1.2"
+    "@inquirer/core" "^10.1.4"
     "@inquirer/type" "^3.0.2"
     yoctocolors-cjs "^2.1.2"
 
-"@inquirer/search@^3.0.4":
-  version "3.0.4"
-  resolved "https://registry.yarnpkg.com/@inquirer/search/-/search-3.0.4.tgz#fcf51a853536add37491920634a182ecc9f5524b"
-  integrity sha512-tSkJk2SDmC2MEdTIjknXWmCnmPr5owTs9/xjfa14ol1Oh95n6xW7SYn5fiPk4/vrJPys0ggSWiISdPze4LTa7A==
+"@inquirer/search@^3.0.6":
+  version "3.0.6"
+  resolved "https://registry.yarnpkg.com/@inquirer/search/-/search-3.0.6.tgz#5537e3f46b7d31ab65ca22b831cf546f88db1d5b"
+  integrity sha512-eFZ2hiAq0bZcFPuFFBmZEtXU1EarHLigE+ENCtpO+37NHCl4+Yokq1P/d09kUblObaikwfo97w+0FtG/EXl5Ng==
   dependencies:
-    "@inquirer/core" "^10.1.2"
+    "@inquirer/core" "^10.1.4"
     "@inquirer/figures" "^1.0.9"
     "@inquirer/type" "^3.0.2"
     yoctocolors-cjs "^2.1.2"
 
-"@inquirer/select@^4.0.4":
-  version "4.0.4"
-  resolved "https://registry.yarnpkg.com/@inquirer/select/-/select-4.0.4.tgz#026ada15754def1cd3fbc01efc56eae45ccc7de4"
-  integrity sha512-ZzYLuLoUzTIW9EJm++jBpRiTshGqS3Q1o5qOEQqgzaBlmdsjQr6pA4TUNkwu6OBYgM2mIRbCz6mUhFDfl/GF+w==
+"@inquirer/select@^4.0.6":
+  version "4.0.6"
+  resolved "https://registry.yarnpkg.com/@inquirer/select/-/select-4.0.6.tgz#3062c02c82f7bbe238972672def6d8394732bb2b"
+  integrity sha512-yANzIiNZ8fhMm4NORm+a74+KFYHmf7BZphSOBovIzYPVLquseTGEkU5l2UTnBOf5k0VLmTgPighNDLE9QtbViQ==
   dependencies:
-    "@inquirer/core" "^10.1.2"
+    "@inquirer/core" "^10.1.4"
     "@inquirer/figures" "^1.0.9"
     "@inquirer/type" "^3.0.2"
     ansi-escapes "^4.3.2"
@@ -925,18 +925,25 @@
   resolved "https://registry.yarnpkg.com/@lit-labs/ssr-dom-shim/-/ssr-dom-shim-1.2.1.tgz#2f3a8f1d688935c704dbc89132394a41029acbb8"
   integrity sha512-wx4aBmgeGvFmOKucFKY+8VFJSYZxs9poN3SDNQFF6lT6NrQUnHiPB2PWz2sc4ieEcAaYYzN+1uWahEeTq2aRIQ==
 
-"@lit/react@^1.0.6":
-  version "1.0.6"
-  resolved "https://registry.yarnpkg.com/@lit/react/-/react-1.0.6.tgz#9518ba471157becd1a3e6fb7ddc16bcef16be64e"
-  integrity sha512-QIss8MPh6qUoFJmuaF4dSHts3qCsA36S3HcOLiNPShxhgYPr4XJRnCBKPipk85sR9xr6TQrOcDMfexwbNdJHYA==
+"@lit/react@^1.0.7":
+  version "1.0.7"
+  resolved "https://registry.yarnpkg.com/@lit/react/-/react-1.0.7.tgz#2ffb7f7b6955a53b7eb53f3557e0dda91d7420ff"
+  integrity sha512-cencnwwLXQKiKxjfFzSgZRngcWJzUDZi/04E0fSaF86wZgchMdvTyu+lE36DrUfvuus3bH8+xLPrhM1cTjwpzw==
 
-"@lit/reactive-element@^2.0.4":
+"@lit/reactive-element@^1.0.0 || ^2.0.0", "@lit/reactive-element@^2.0.4":
   version "2.0.4"
   resolved "https://registry.yarnpkg.com/@lit/reactive-element/-/reactive-element-2.0.4.tgz#8f2ed950a848016383894a26180ff06c56ae001b"
   integrity sha512-GFn91inaUa2oHLak8awSIigYz0cU0Payr1rcFsrkf5OJ5eSPxElyZfKh0f2p9FsTiZWXQdWGJeXZICEfXXYSXQ==
   dependencies:
     "@lit-labs/ssr-dom-shim" "^1.2.0"
 
+"@lit/task@^1.0.2":
+  version "1.0.2"
+  resolved "https://registry.yarnpkg.com/@lit/task/-/task-1.0.2.tgz#2d1da95c3cdbb371479944eead3f1d9bf2c60bbb"
+  integrity sha512-ofj/fahKhhS1SpbPSC57OMo2BXMxHG/y4sxH/ahWzXT5dh1kxjex7WqbL8ammb6zIlqbFCj6z2aGFYOh/qCQ+g==
+  dependencies:
+    "@lit/reactive-element" "^1.0.0 || ^2.0.0"
+
 "@marijn/find-cluster-break@^1.0.0":
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/@marijn/find-cluster-break/-/find-cluster-break-1.0.2.tgz#775374306116d51c0c500b8c4face0f9a04752d8"
@@ -947,15 +954,15 @@
   resolved "https://registry.yarnpkg.com/@mdn/bcd-utils-api/-/bcd-utils-api-0.0.7.tgz#555e80c33df520df068943e6b18ebc07f0e24d19"
   integrity sha512-IHkkypEjlIkBkx4mJ2//Xbzog9M/Lzne1Sl8db2cIHJ/5pe3NCqSLwSchmqzcUN+/WJr/U+V3tNAbWunk2xZcA==
 
-"@mdn/browser-compat-data@^5.6.28":
-  version "5.6.28"
-  resolved "https://registry.yarnpkg.com/@mdn/browser-compat-data/-/browser-compat-data-5.6.28.tgz#bce08f898f2bf86ccaa5d79cef30e8ae26165e76"
-  integrity sha512-tMEFXKQXHbWsndyTtLkheUAMlN/oKGqXeP6iSQuDJ3VwPZD5qkkSb+BNmFkO67EWyC2kJbOu79/XJ+pSiF8LZQ==
+"@mdn/browser-compat-data@^5.6.32":
+  version "5.6.32"
+  resolved "https://registry.yarnpkg.com/@mdn/browser-compat-data/-/browser-compat-data-5.6.32.tgz#1b19eea918a458d6da77527b82cb935fe1ac8498"
+  integrity sha512-z5ygobHDF+1XrBK5opSziQT6uY76tpEb6JStUpFppnwgwmBslfsSuZDzHTl2SzqYX69Ge3kM//zNO0u8btcdow==
 
-"@mdn/rari@^0.1.16":
-  version "0.1.16"
-  resolved "https://registry.yarnpkg.com/@mdn/rari/-/rari-0.1.16.tgz#a6d3ecf4712dd2bb7422a779f3b9cd3593ab7caa"
-  integrity sha512-AlWNyrkJUD2MKKTBUWH+G7/q8ahx89FfoHzGOGt2qlWDZcxTKKFjh4YQM3mbsn3iaronvcg9RsXjqdj75XmimA==
+"@mdn/rari@^0.1.19":
+  version "0.1.19"
+  resolved "https://registry.yarnpkg.com/@mdn/rari/-/rari-0.1.19.tgz#5b879095e71dd9d5d51b51a598a1fd5d33e43842"
+  integrity sha512-xSyNIivcvi0Y872yh+ipqwfwuvNFT993bUJYLej8KGDOZ6gYMj8gbzVFRVQWfteV3/vDH12nusXNMuYn9nu9Ow==
   dependencies:
     extract-zip "^2.0.1"
     https-proxy-agent "^7.0.2"
@@ -963,10 +970,10 @@
     proxy-from-env "^1.1.0"
     tar "^7.4.3"
 
-"@mdn/yari@4.1.2":
-  version "4.1.2"
-  resolved "https://registry.yarnpkg.com/@mdn/yari/-/yari-4.1.2.tgz#16d5d00452ad36dc2cc28596c14b0cec8afff6a3"
-  integrity sha512-dVhZI3dykP6UloqTlFP/p/lYNLJo5aXa73kDhEB3vQss98IBKfH6/Fo8bGiz8J9UT3RbrI4Uj6DvEyRMAsSPWQ==
+"@mdn/yari@4.2.0":
+  version "4.2.0"
+  resolved "https://registry.yarnpkg.com/@mdn/yari/-/yari-4.2.0.tgz#07c127c270680a13a34399c70197186d4d6925a8"
+  integrity sha512-COGho4rHpQh+XUqtqUck8895YawhQy6Ifixch3EJxQxlMz0aJEmXnfHum7aW5sp/OShjYbwqS8+scLErlKkoIA==
   dependencies:
     "@caporal/core" "^2.0.7"
     "@codemirror/lang-css" "^6.3.1"
@@ -975,16 +982,17 @@
     "@codemirror/state" "^6.5.1"
     "@codemirror/theme-one-dark" "^6.1.2"
     "@fast-csv/parse" "^5.0.2"
-    "@inquirer/prompts" "^7.2.1"
-    "@lit/react" "^1.0.6"
+    "@inquirer/prompts" "^7.2.3"
+    "@lit/react" "^1.0.7"
+    "@lit/task" "^1.0.2"
     "@mdn/bcd-utils-api" "^0.0.7"
-    "@mdn/browser-compat-data" "^5.6.28"
-    "@mdn/rari" "^0.1.16"
+    "@mdn/browser-compat-data" "^5.6.32"
+    "@mdn/rari" "^0.1.19"
     "@mozilla/glean" "5.0.3"
-    "@sentry/node" "^8.48.0"
+    "@sentry/node" "^8.51.0"
     "@stripe/stripe-js" "^5.5.0"
     "@use-it/interval" "^1.0.0"
-    "@vscode/ripgrep" "^1.15.9"
+    "@vscode/ripgrep" "^1.15.10"
     "@webref/css" "^6.17.5"
     accept-language-parser "^1.5.0"
     async "^3.2.6"
@@ -1000,15 +1008,15 @@
     cross-spawn "^7.0.6"
     css-tree "^2.3.1"
     dayjs "^1.11.13"
-    dexie "^4.0.10"
+    dexie "^4.0.11"
     dotenv "^16.4.7"
     ejs "^3.1.10"
     express "^4.21.2"
-    fdir "^6.4.2"
+    fdir "^6.4.3"
     feed "^4.2.2"
     file-type "^19.6.0"
     front-matter "^4.0.2"
-    fs-extra "^11.2.0"
+    fs-extra "^11.3.0"
     got "^13.0.0"
     http-proxy-middleware "^2.0.7"
     image-size "^1.2.0"
@@ -1026,10 +1034,10 @@
     md5-file "^5.0.0"
     mdast-util-from-markdown "^2.0.2"
     mdast-util-phrasing "^4.1.0"
-    mdn-data "^2.14.0"
+    mdn-data "^2.15.0"
     open "^10.1.0"
     open-editor "^5.1.0"
-    openai "^4.78.0"
+    openai "^4.80.0"
     pg "^8.13.1"
     pgvector "^0.2.0"
     prism-svelte "^0.5.0"
@@ -1055,8 +1063,8 @@
     unified "^11.0.5"
     unist-builder "^4.0.0"
     unist-util-visit "^5.0.0"
-    web-features "^2.16.0"
-    web-specs "^3.32.0"
+    web-features "^2.19.0"
+    web-specs "^3.35.0"
 
 "@mozilla/glean@5.0.3":
   version "5.0.3"
@@ -1433,15 +1441,15 @@
   resolved "https://registry.yarnpkg.com/@sec-ant/readable-stream/-/readable-stream-0.4.1.tgz#60de891bb126abfdc5410fdc6166aca065f10a0c"
   integrity sha512-831qok9r2t8AlxLko40y2ebgSDhenenCatLVeW/uBtnHPyhHOvG0C7TvfgecV+wHzIm5KUICgzmVpWS+IMEAeg==
 
-"@sentry/core@8.48.0":
-  version "8.48.0"
-  resolved "https://registry.yarnpkg.com/@sentry/core/-/core-8.48.0.tgz#3bb8d06305f0ec7c873453844687deafdeab168b"
-  integrity sha512-VGwYgTfLpvJ5LRO5A+qWo1gpo6SfqaGXL9TOzVgBucAdpzbrYHpZ87sEarDVq/4275uk1b0S293/mfsskFczyw==
+"@sentry/core@8.51.0":
+  version "8.51.0"
+  resolved "https://registry.yarnpkg.com/@sentry/core/-/core-8.51.0.tgz#d0c73dfe3489788911b7ce784d3ef8458344482c"
+  integrity sha512-Go0KxCYLw+OBIlLSv5YsYX+x9NW43fNVcyB6rhkSp2Q5Zme3tAE6KtZFvyu4SO7G/903wisW5Q6qV6UuK/ee4A==
 
-"@sentry/node@^8.48.0":
-  version "8.48.0"
-  resolved "https://registry.yarnpkg.com/@sentry/node/-/node-8.48.0.tgz#d4d1374431028af7663a06bf7268bf40a9bf1fa0"
-  integrity sha512-pnprAuUOc8cxnJdZA09hutHXNsbQZoDgzf3zPyXMNx0ewB/RviFMOgfe7ViX1mIB/oVrcFenXBgO5uvTd7JwPg==
+"@sentry/node@^8.51.0":
+  version "8.51.0"
+  resolved "https://registry.yarnpkg.com/@sentry/node/-/node-8.51.0.tgz#c267b536ea6c3357e3c59de8d4b40dbfab3dff45"
+  integrity sha512-KfXk3QaeNXmJgUUCDAwZW7cdZ+1GvRXNdTPLpWbAKGaNulAeimck5fGGL8FRMSF0sMz6BT6Ku7u6DUaZTtbB7w==
   dependencies:
     "@opentelemetry/api" "^1.9.0"
     "@opentelemetry/context-async-hooks" "^1.29.0"
@@ -1475,16 +1483,16 @@
     "@opentelemetry/sdk-trace-base" "^1.29.0"
     "@opentelemetry/semantic-conventions" "^1.28.0"
     "@prisma/instrumentation" "5.22.0"
-    "@sentry/core" "8.48.0"
-    "@sentry/opentelemetry" "8.48.0"
+    "@sentry/core" "8.51.0"
+    "@sentry/opentelemetry" "8.51.0"
     import-in-the-middle "^1.11.2"
 
-"@sentry/opentelemetry@8.48.0":
-  version "8.48.0"
-  resolved "https://registry.yarnpkg.com/@sentry/opentelemetry/-/opentelemetry-8.48.0.tgz#718e7942724d64ffe8e901941b0e4050fa07780b"
-  integrity sha512-1JLXgmIvD3T7xn9ypwWW0V3GirNy4BN2fOUbZau/nUX/Jj5DttSoPn7x7xTaPSpfaA24PiP93zXmJEfZvCk00Q==
+"@sentry/opentelemetry@8.51.0":
+  version "8.51.0"
+  resolved "https://registry.yarnpkg.com/@sentry/opentelemetry/-/opentelemetry-8.51.0.tgz#376b1017da140372a904d712d80ed2ec4d361ee4"
+  integrity sha512-SvH/rl/P+S7EKXIZA6kq2HzFYfXKQx8Ytgx4WZJV+katsdaDay24QtycYE+PaqbotAkV6MOMECEb8a9XXttQcg==
   dependencies:
-    "@sentry/core" "8.48.0"
+    "@sentry/core" "8.51.0"
 
 "@sinclair/typebox@^0.27.8":
   version "0.27.8"
@@ -1843,10 +1851,10 @@
   resolved "https://registry.yarnpkg.com/@use-it/interval/-/interval-1.0.0.tgz#c42c68f22ca29a0dc929041746373d94496d2b3a"
   integrity sha512-WQFcnSt/xM/mS8ZtJ0ut5lhPrl+V0HDPPcI/J0eUClsfiD+/r8A7IeW/pVcfpSVGWRmN3+WnjNteWuKyWs2WZg==
 
-"@vscode/ripgrep@^1.15.9":
-  version "1.15.9"
-  resolved "https://registry.yarnpkg.com/@vscode/ripgrep/-/ripgrep-1.15.9.tgz#92279f7f28e1e49ad9a89603e10b17a4c7f9f5f1"
-  integrity sha512-4q2PXRvUvr3bF+LsfrifmUZgSPmCNcUZo6SbEAZgArIChchkezaxLoIeQMJe/z3CCKStvaVKpBXLxN3Z8lQjFQ==
+"@vscode/ripgrep@^1.15.10":
+  version "1.15.10"
+  resolved "https://registry.yarnpkg.com/@vscode/ripgrep/-/ripgrep-1.15.10.tgz#521cd6fc2a514448aee3ff878ddf13028cdbe5bb"
+  integrity sha512-83Q6qFrELpFgf88bPOcwSWDegfY2r/cb6bIfdLTSZvN73Dg1wviSfO+1v6lTFMd0mAvUYYcTUu+Mn5xMroZMxA==
   dependencies:
     https-proxy-agent "^7.0.2"
     proxy-from-env "^1.1.0"
@@ -2460,7 +2468,7 @@ chalk@^4.0.0, chalk@^4.0.2, chalk@^4.1.2:
     ansi-styles "^4.1.0"
     supports-color "^7.1.0"
 
-chalk@^5.4.1, chalk@~5.4.1:
+chalk@^5.4.1:
   version "5.4.1"
   resolved "https://registry.yarnpkg.com/chalk/-/chalk-5.4.1.tgz#1b48bf0963ec158dce2aacf69c093ae2dd2092d8"
   integrity sha512-zgVZuo2WcZgfUEmsn6eO3kINexW8RAE4maiQ8QNs8CtpPCSyMiYsULR3HQYkm3w8FIA3SberyMJMSldGsW+U3w==
@@ -2720,6 +2728,11 @@ comma-separated-tokens@^2.0.0:
   resolved "https://registry.yarnpkg.com/comma-separated-tokens/-/comma-separated-tokens-2.0.3.tgz#4e89c9458acb61bc8fef19f4529973b2392839ee"
   integrity sha512-Fu4hJdvzeylCfQPp9SGWidpzrMs7tTrlu6Vb8XGaRGck8QSNZJJp538Wrb60Lax4fPwR64ViY468OIUTbRlGZg==
 
+commander@^13.1.0:
+  version "13.1.0"
+  resolved "https://registry.yarnpkg.com/commander/-/commander-13.1.0.tgz#776167db68c78f38dcce1f9b8d7b8b9a488abf46"
+  integrity sha512-/rFeCpNJQbhSZjGVwO9RFV3xPqbnERS8MmIQzCtD/zl6gpJuV/bMLuN92oG3F7d8oDEHHRrujSXNUr8fpjntKw==
+
 commander@^2.8.1:
   version "2.20.3"
   resolved "https://registry.yarnpkg.com/commander/-/commander-2.20.3.tgz#fd485e84c03eb4881c20722ba48035e8531aeb33"
@@ -2740,11 +2753,6 @@ commander@^8.3.0:
   resolved "https://registry.yarnpkg.com/commander/-/commander-8.3.0.tgz#4837ea1b2da67b9c616a67afbb0fafee567bca66"
   integrity sha512-OkTL9umf+He2DZkUq8f8J9of7yL6RJKI24dVITBmNfZBmri9zYZQrKkuXiKhyfPSu8tUhnVBB1iKXevvnlR4Ww==
 
-commander@~12.1.0:
-  version "12.1.0"
-  resolved "https://registry.yarnpkg.com/commander/-/commander-12.1.0.tgz#01423b36f501259fdaac4d0e4d60c96c991585d3"
-  integrity sha512-Vw8qHK3bZM9y/P10u3Vib8o/DdkvA2OtPtZvD871QKjy74Wj1WSKFILMPRPSdUSx5RFK1arlJzEtA4PkFgnbuA==
-
 compare-versions@^6.1.0:
   version "6.1.1"
   resolved "https://registry.yarnpkg.com/compare-versions/-/compare-versions-6.1.1.tgz#7af3cc1099ba37d244b3145a9af5201b629148a9"
@@ -2981,7 +2989,7 @@ debug@2.6.9, debug@^2.2.0:
   dependencies:
     ms "2.0.0"
 
-debug@4, debug@^4.0.0, debug@^4.0.1, debug@^4.1.0, debug@^4.1.1, debug@^4.3.1, debug@^4.3.4, debug@^4.3.5, debug@~4.4.0:
+debug@4, debug@^4.0.0, debug@^4.0.1, debug@^4.1.0, debug@^4.1.1, debug@^4.3.1, debug@^4.3.4, debug@^4.3.5, debug@^4.4.0:
   version "4.4.0"
   resolved "https://registry.yarnpkg.com/debug/-/debug-4.4.0.tgz#2b3f2aea2ffeb776477460267377dc8710faba8a"
   integrity sha512-6WTZ/IxCY/T6BALoZHaE4ctp9xm+Z5kY/pzYaCHRFeyVhojxlrm+46y68HA6hr0TcwEssoxNiDEUJQjfPZ/RYA==
@@ -3146,10 +3154,10 @@ devlop@^1.0.0, devlop@^1.1.0:
   dependencies:
     dequal "^2.0.0"
 
-dexie@^4.0.10:
-  version "4.0.10"
-  resolved "https://registry.yarnpkg.com/dexie/-/dexie-4.0.10.tgz#979e3ee75993b44eea3852f97ceb198019d5b287"
-  integrity sha512-eM2RzuR3i+M046r2Q0Optl3pS31qTWf8aFuA7H9wnsHTwl8EPvroVLwvQene/6paAs39Tbk6fWZcn2aZaHkc/w==
+dexie@^4.0.11:
+  version "4.0.11"
+  resolved "https://registry.yarnpkg.com/dexie/-/dexie-4.0.11.tgz#010a2c82dd35d40aa9a81c8d21951bfeb487b7d6"
+  integrity sha512-SOKO002EqlvBYYKQSew3iymBoN2EQ4BDw/3yprjh7kAfFzjBYkaMNa/pZvcA7HSWlcKSQb9XhPe3wKyQ0x4A8A==
 
 diff-sequences@^29.6.3:
   version "29.6.3"
@@ -3465,7 +3473,7 @@ execa@^6.0.0:
     signal-exit "^3.0.7"
     strip-final-newline "^3.0.0"
 
-execa@^8.0.1, execa@~8.0.1:
+execa@^8.0.1:
   version "8.0.1"
   resolved "https://registry.yarnpkg.com/execa/-/execa-8.0.1.tgz#51f6a5943b580f963c3ca9c6321796db8cc39b8c"
   integrity sha512-VyhnebXciFV2DESc+p6B+y0LjSm0krU4OgJN44qFAhBY0TJ+1V61tYD2+wHusZ6F9n5K+vl8k0sTy7PEfV4qpg==
@@ -3693,10 +3701,10 @@ fd-slicer@~1.1.0:
   dependencies:
     pend "~1.2.0"
 
-fdir@^6.4.2:
-  version "6.4.2"
-  resolved "https://registry.yarnpkg.com/fdir/-/fdir-6.4.2.tgz#ddaa7ce1831b161bc3657bb99cb36e1622702689"
-  integrity sha512-KnhMXsKSPZlAhp7+IjUkRZKPb4fUyccpDrdFXbi4QL1qkmFh9kVY09Yox+n4MaOb3lHZ1Tv829C3oaaXoMYPDQ==
+fdir@^6.4.2, fdir@^6.4.3:
+  version "6.4.3"
+  resolved "https://registry.yarnpkg.com/fdir/-/fdir-6.4.3.tgz#011cdacf837eca9b811c89dbb902df714273db72"
+  integrity sha512-PMXmW2y1hDDfTSRc9gaXIuCCRpuoz3Kaz8cUelp3smouvfT632ozg2vrT6lJsHKKOF59YLbOGfAWGUcKEfRMQw==
 
 fecha@^4.2.0:
   version "4.2.3"
@@ -3913,10 +3921,10 @@ fs-constants@^1.0.0:
   resolved "https://registry.yarnpkg.com/fs-constants/-/fs-constants-1.0.0.tgz#6be0de9be998ce16af8afc24497b9ee9b7ccd9ad"
   integrity sha512-y6OAwoSIf7FyjMIv94u+b5rdheZEjzR63GTyZJm5qh4Bi+2YgwLCcI/fPFZkL5PSixOt6ZNKm+w+Hfp/Bciwow==
 
-fs-extra@^11.2.0:
-  version "11.2.0"
-  resolved "https://registry.yarnpkg.com/fs-extra/-/fs-extra-11.2.0.tgz#e70e17dfad64232287d01929399e0ea7c86b0e5b"
-  integrity sha512-PmDi3uwK5nFuXh7XDTlVnS17xJS7vW36is2+w3xcv8SVxiB4NyATf4ctkVY5bkSjX0Y4nbvZCq1/EjtEyr9ktw==
+fs-extra@^11.3.0:
+  version "11.3.0"
+  resolved "https://registry.yarnpkg.com/fs-extra/-/fs-extra-11.3.0.tgz#0daced136bbaf65a555a326719af931adc7a314d"
+  integrity sha512-Z4XaCL6dUDHfP/jT25jJKMmtxvuwbkrD1vNSMFlo9lNLY2c5FHYSQgHPRZUjAB26TpDEoW9HCOgplrdbaPV/ew==
   dependencies:
     graceful-fs "^4.2.0"
     jsonfile "^6.0.1"
@@ -5540,9 +5548,9 @@ junk@^4.0.1:
   integrity sha512-Qush0uP+G8ZScpGMZvHUiRfI0YBWuB3gVBYlI0v0vvOJt5FLicco+IkP0a50LqTTQhmts/m6tP5SWE+USyIvcQ==
 
 katex@^0.16.0:
-  version "0.16.18"
-  resolved "https://registry.yarnpkg.com/katex/-/katex-0.16.18.tgz#20781284288bc52805c519e48ac756163ad4b1f3"
-  integrity sha512-LRuk0rPdXrecAFwQucYjMiIs0JFefk6N1q/04mlw14aVIVgxq1FO0MA9RiIIGVaKOB5GIP5GH4aBBNraZERmaQ==
+  version "0.16.21"
+  resolved "https://registry.yarnpkg.com/katex/-/katex-0.16.21.tgz#8f63c659e931b210139691f2cc7bb35166b792a3"
+  integrity sha512-XvqR7FgOHtWupfMiigNzmh+MgUVmDGU2kXZm899ZkPfcuoPuFxyHmXsgATDpFZDAXCI8tvinaVcDo8PIIJSo4A==
   dependencies:
     commander "^8.3.0"
 
@@ -5580,7 +5588,7 @@ leven@^3.1.0:
   resolved "https://registry.yarnpkg.com/leven/-/leven-3.1.0.tgz#77891de834064cccba82ae7842bb6b14a13ed7f2"
   integrity sha512-qsda+H8jTaUaN/x5vzW2rzc+8Rw4TAQ/4KjB46IwK5VH+IlVeeeje/EoZRpiXvIqjFgK84QffqPztGI3VBLG1A==
 
-lilconfig@~3.1.3:
+lilconfig@^3.1.3:
   version "3.1.3"
   resolved "https://registry.yarnpkg.com/lilconfig/-/lilconfig-3.1.3.tgz#a1bcfd6257f9585bf5ae14ceeebb7b559025e4c4"
   integrity sha512-/vlFKAoH5Cgt3Ie+JLhRbwOsCQePABiU3tJ1egGvyQ+33R/vcwM2Zl2QR/LzjsBeItPt3oSVXapn+m4nQDvpzw==
@@ -5604,23 +5612,23 @@ linkify-it@^5.0.0:
   dependencies:
     uc.micro "^2.0.0"
 
-lint-staged@15.3.0:
-  version "15.3.0"
-  resolved "https://registry.yarnpkg.com/lint-staged/-/lint-staged-15.3.0.tgz#32a0b3f2f2b8825950bd3b9fb093e045353bdfa3"
-  integrity sha512-vHFahytLoF2enJklgtOtCtIjZrKD/LoxlaUusd5nh7dWv/dkKQJY74ndFSzxCdv7g0ueGg1ORgTSt4Y9LPZn9A==
-  dependencies:
-    chalk "~5.4.1"
-    commander "~12.1.0"
-    debug "~4.4.0"
-    execa "~8.0.1"
-    lilconfig "~3.1.3"
-    listr2 "~8.2.5"
-    micromatch "~4.0.8"
-    pidtree "~0.6.0"
-    string-argv "~0.3.2"
-    yaml "~2.6.1"
-
-listr2@~8.2.5:
+lint-staged@15.4.2:
+  version "15.4.2"
+  resolved "https://registry.yarnpkg.com/lint-staged/-/lint-staged-15.4.2.tgz#f986bcb6b03822a996c600447c692c69640c7607"
+  integrity sha512-gCqzB/Li281uZJgReNci+oXXqUEdrFAQAzTE/LwoxxiEuP41vozNe4BATS+4ehdqkWn+Z6bGc3EDcBja3npBVw==
+  dependencies:
+    chalk "^5.4.1"
+    commander "^13.1.0"
+    debug "^4.4.0"
+    execa "^8.0.1"
+    lilconfig "^3.1.3"
+    listr2 "^8.2.5"
+    micromatch "^4.0.8"
+    pidtree "^0.6.0"
+    string-argv "^0.3.2"
+    yaml "^2.7.0"
+
+listr2@^8.2.5:
   version "8.2.5"
   resolved "https://registry.yarnpkg.com/listr2/-/listr2-8.2.5.tgz#5c9db996e1afeb05db0448196d3d5f64fec2593d"
   integrity sha512-iyAZCeyD+c1gPyE9qpFu8af0Y+MRtmKOncdGoA2S5EY8iFq99dmmvkNnHiWo+pj0s7yH7l3KPIgee77tKpXPWQ==
@@ -5842,15 +5850,15 @@ markdownlint-cli2-formatter-default@0.0.5:
   resolved "https://registry.yarnpkg.com/markdownlint-cli2-formatter-default/-/markdownlint-cli2-formatter-default-0.0.5.tgz#b8fde4e127f9a9c0596e6d45eed352dd0aa0ff98"
   integrity sha512-4XKTwQ5m1+Txo2kuQ3Jgpo/KmnG+X90dWt4acufg6HVGadTUG5hzHF/wssp9b5MBYOMCnZ9RMPaU//uHsszF8Q==
 
-markdownlint-cli2@0.17.1:
-  version "0.17.1"
-  resolved "https://registry.yarnpkg.com/markdownlint-cli2/-/markdownlint-cli2-0.17.1.tgz#4455105fe5d75821597779f7a442ce5c5ce0fede"
-  integrity sha512-n1Im9lhKJJE12/u2N0GWBwPqeb0HGdylN8XpSFg9hbj35+QalY9Vi6mxwUQdG6wlSrrIq9ZDQ0Q85AQG9V2WOg==
+markdownlint-cli2@0.17.2:
+  version "0.17.2"
+  resolved "https://registry.yarnpkg.com/markdownlint-cli2/-/markdownlint-cli2-0.17.2.tgz#8d3dc2637fae42cea01fe3bf218501cbf33a7cd5"
+  integrity sha512-XH06ZOi8wCrtOSSj3p8y3yJzwgzYOSa7lglNyS3fP05JPRzRGyjauBb5UvlLUSCGysMmULS1moxdRHHudV+g/Q==
   dependencies:
     globby "14.0.2"
     js-yaml "4.1.0"
     jsonc-parser "3.3.1"
-    markdownlint "0.37.3"
+    markdownlint "0.37.4"
     markdownlint-cli2-formatter-default "0.0.5"
     micromatch "4.0.8"
 
@@ -5873,10 +5881,10 @@ markdownlint-rule-search-replace@1.2.0:
   dependencies:
     markdownlint-rule-helpers "0.21.0"
 
-markdownlint@0.37.3:
-  version "0.37.3"
-  resolved "https://registry.yarnpkg.com/markdownlint/-/markdownlint-0.37.3.tgz#061ac5462e97fedc7a96aaac5c132885e4161bfd"
-  integrity sha512-eoQqH0291YCCjd+Pe1PUQ9AmWthlVmS0XWgcionkZ8q34ceZyRI+pYvsWksXJJL8OBkWCPwp1h/pnXxrPFC4oA==
+markdownlint@0.37.4:
+  version "0.37.4"
+  resolved "https://registry.yarnpkg.com/markdownlint/-/markdownlint-0.37.4.tgz#dd58c4a13b798d4702438e5f7fd587a219f753f6"
+  integrity sha512-u00joA/syf3VhWh6/ybVFkib5Zpj2e5KB/cfCei8fkSRuums6nyisTWGqjTWIOFoFwuXoTBQQiqlB4qFKp8ncQ==
   dependencies:
     markdown-it "14.1.0"
     micromark "4.0.1"
@@ -6082,10 +6090,10 @@ mdn-data@2.0.30:
   resolved "https://registry.yarnpkg.com/mdn-data/-/mdn-data-2.0.30.tgz#ce4df6f80af6cfbe218ecd5c552ba13c4dfa08cc"
   integrity sha512-GaqWWShW4kv/G9IEucWScBx9G1/vsFZZJUO+tD26M8J8z3Kw5RDQjaoZe03YAClgeS/SWPOcb4nkFBTEi5DUEA==
 
-mdn-data@^2.14.0:
-  version "2.14.0"
-  resolved "https://registry.yarnpkg.com/mdn-data/-/mdn-data-2.14.0.tgz#043dfa5db6b00cbb389e70ebc457c5d17591e17b"
-  integrity sha512-QjcSiIvUHjmXp5wNLClRjQeU0Zp+I2Dag+AhtQto0nyKYZ3IF/pUzCuHe7Bv77EC92XE5t3EXeEiEv/to2Bwig==
+mdn-data@^2.15.0:
+  version "2.15.0"
+  resolved "https://registry.yarnpkg.com/mdn-data/-/mdn-data-2.15.0.tgz#8d8bc0d9a463edf4296c418a8b49d3a8b2c686fb"
+  integrity sha512-KIrS0lFPOqA4DgeO16vI5fkAsy8p++WBlbXtB5P1EQs8ubBgguAInNd1DnrCeTRfGchY0kgThgDOOIPyOLH2dQ==
 
 mdurl@^2.0.0:
   version "2.0.0"
@@ -6466,7 +6474,7 @@ micromark@^4.0.0:
     micromark-util-symbol "^2.0.0"
     micromark-util-types "^2.0.0"
 
-micromatch@4.0.8, micromatch@^4.0.2, micromatch@^4.0.4, micromatch@~4.0.8:
+micromatch@4.0.8, micromatch@^4.0.2, micromatch@^4.0.4, micromatch@^4.0.8:
   version "4.0.8"
   resolved "https://registry.yarnpkg.com/micromatch/-/micromatch-4.0.8.tgz#d66fa18f3a47076789320b9b1af32bd86d9fa202"
   integrity sha512-PXwfBhYu0hBCPw8Dn0E+WDYb7af3dSLVWKi3HGv84IdF4TyFoC0ysxFd0Goxw7nSv4T/PzEJQxsYsEiFCKo2BA==
@@ -6832,10 +6840,10 @@ open@^10.1.0:
     is-inside-container "^1.0.0"
     is-wsl "^3.1.0"
 
-openai@^4.78.0:
-  version "4.78.0"
-  resolved "https://registry.yarnpkg.com/openai/-/openai-4.78.0.tgz#79a021de5247944f63c250bdc78e9aa74c8b2236"
-  integrity sha512-4rRsKkx++5m1zayxkryVH+K/z91cv1sRbaNJAhSQjZiSCQOR7eaM8KpfIssXrS9Hlpta7+VcuO/fi57pW8xGjA==
+openai@^4.80.0:
+  version "4.80.0"
+  resolved "https://registry.yarnpkg.com/openai/-/openai-4.80.0.tgz#693e5be69a21ed31658a5e0cd8132056cd7a6fb8"
+  integrity sha512-5TqdNQgjOMxo3CkCvtjzuSwuznO/o3q5aak0MTy6IjRvPtvVA1wAFGJU3eZT1JHzhs2wFb/xtDG0o6Y/2KGCfw==
   dependencies:
     "@types/node" "^18.11.18"
     "@types/node-fetch" "^2.6.4"
@@ -7181,7 +7189,7 @@ picomatch@^4.0.2:
   resolved "https://registry.yarnpkg.com/picomatch/-/picomatch-4.0.2.tgz#77c742931e8f3b8820946c76cd0c1f13730d1dab"
   integrity sha512-M7BAV6Rlcy5u+m6oPhAPFgJTzAioX/6B0DxyvDlo9l8+T3nLKbrczg2WLUyzd45L8RqfUMyGPzekbMvX2Ldkwg==
 
-pidtree@~0.6.0:
+pidtree@^0.6.0:
   version "0.6.0"
   resolved "https://registry.yarnpkg.com/pidtree/-/pidtree-0.6.0.tgz#90ad7b6d42d5841e69e0a2419ef38f8883aa057c"
   integrity sha512-eG2dWTVw5bzqGRztnHExczNxt5VGsE6OwTeCG3fdUf9KBsZzO3R5OIIIzWR+iZA0NtZ+RDVdaoE2dK1cn6jH4g==
@@ -8115,7 +8123,7 @@ strict-uri-encode@^1.0.0:
   resolved "https://registry.yarnpkg.com/strict-uri-encode/-/strict-uri-encode-1.1.0.tgz#279b225df1d582b1f54e65addd4352e18faa0713"
   integrity sha512-R3f198pcvnB+5IpnBlRkphuE9n46WyVl8I39W/ZUTZLz4nqSP/oLYUrcnJrw462Ds8he4YKMov2efsTIw1BDGQ==
 
-string-argv@~0.3.2:
+string-argv@^0.3.2:
   version "0.3.2"
   resolved "https://registry.yarnpkg.com/string-argv/-/string-argv-0.3.2.tgz#2b6d0ef24b656274d957d54e0a4bbf6153dc02b6"
   integrity sha512-aqD2Q0144Z+/RqG52NeHEkZauTAUWJO8c6yTftGJKO3Tja5tUgIfmIl6kExvhtxSDP7fXB6DvzkfMpCd/F3G+Q==
@@ -8898,20 +8906,20 @@ warning@^4.0.3:
   dependencies:
     loose-envify "^1.0.0"
 
-web-features@^2.16.0:
-  version "2.16.0"
-  resolved "https://registry.yarnpkg.com/web-features/-/web-features-2.16.0.tgz#30c80a358e41a35b9b7b9417a5fe3905f7823aad"
-  integrity sha512-TuUw2NSpo6TE20bGuY2bSOefedn382M2MrwHJ05FKSxfyeBoqxfCvIHyQcq2NHh92Hjvt50AX31bqLzNEb68Tw==
+web-features@^2.19.0:
+  version "2.19.0"
+  resolved "https://registry.yarnpkg.com/web-features/-/web-features-2.19.0.tgz#9db1e76d737b2140799682d89f5a48e3f0bff090"
+  integrity sha512-uhWvB/07YJfBLG+E4jHwc2byuBsbJUKrvBhJr64SX87K7veXHqJjKOuqzwI+h00LwU5MExKiiALLSuh/fYfxzw==
 
 web-namespaces@^2.0.0:
   version "2.0.1"
   resolved "https://registry.yarnpkg.com/web-namespaces/-/web-namespaces-2.0.1.tgz#1010ff7c650eccb2592cebeeaf9a1b253fd40692"
   integrity sha512-bKr1DkiNa2krS7qxNtdrtHAmzuYGFQLiQ13TsorsdT6ULTkPLKuu5+GsFpDlg6JFjUTwX2DyhMPG2be8uPrqsQ==
 
-web-specs@^3.32.0:
-  version "3.32.0"
-  resolved "https://registry.yarnpkg.com/web-specs/-/web-specs-3.32.0.tgz#56a8c89854c374a50dea15198cc91fea2db8b7a1"
-  integrity sha512-cYNoNsODIhOTY0cB2SwUll2WMhLywgnkVXabiUAi31+lDbyck5Gfsuio/LtHKPzwWtoT1yK3UkMBVT4cfcFR/g==
+web-specs@^3.35.0:
+  version "3.35.0"
+  resolved "https://registry.yarnpkg.com/web-specs/-/web-specs-3.35.0.tgz#27de67081d39d706ec44a03775dbc9166a38e297"
+  integrity sha512-C0Fs9B39exvcWvkf46jBumUoC4Ki4JMkcDh3bebTNKKksmo0j0tJ1V0Indkm4JH+Lc2PD+0ROrV2TMoYYHpjvA==
 
 web-streams-polyfill@4.0.0-beta.3:
   version "4.0.0-beta.3"
@@ -9073,10 +9081,10 @@ yallist@^5.0.0:
   resolved "https://registry.yarnpkg.com/yallist/-/yallist-5.0.0.tgz#00e2de443639ed0d78fd87de0d27469fbcffb533"
   integrity sha512-YgvUTfwqyc7UXVMrB+SImsVYSmTS8X/tSrtdNZMImM+n7+QTriRXyXim0mBrTXNeqzVF0KWGgHPeiyViFFrNDw==
 
-yaml@~2.6.1:
-  version "2.6.1"
-  resolved "https://registry.yarnpkg.com/yaml/-/yaml-2.6.1.tgz#42f2b1ba89203f374609572d5349fb8686500773"
-  integrity sha512-7r0XPzioN/Q9kXBro/XPnA6kznR73DHq+GXh5ON7ZozRO6aMjbmiBuKste2wslTFkC5d1dw0GooOCepZXJ2SAg==
+yaml@^2.7.0:
+  version "2.7.0"
+  resolved "https://registry.yarnpkg.com/yaml/-/yaml-2.7.0.tgz#aef9bb617a64c937a9a748803786ad8d3ffe1e98"
+  integrity sha512-+hSoy/QHluxmC9kCIJyL/uyFmLmc+e5CFR5Wa+bpIhIj85LVb9ZH2nVnqrHoSvKogwODv0ClqZkmiSSaIH5LTA==
 
 yargs-parser@^21.1.1:
   version "21.1.1"