diff --git a/app/javascript/mastodon/components/edited_timestamp/index.jsx b/app/javascript/mastodon/components/edited_timestamp/index.jsx
index fbf14ec4bde..f8fa0432597 100644
--- a/app/javascript/mastodon/components/edited_timestamp/index.jsx
+++ b/app/javascript/mastodon/components/edited_timestamp/index.jsx
@@ -6,6 +6,7 @@ import { FormattedMessage, injectIntl } from 'react-intl';
 import { connect } from 'react-redux';
 
 import { openModal } from 'mastodon/actions/modal';
+import { FormattedDateWrapper } from 'mastodon/components/formatted_date';
 import InlineAccount from 'mastodon/components/inline_account';
 import { RelativeTimestamp } from 'mastodon/components/relative_timestamp';
 
@@ -60,12 +61,12 @@ class EditedTimestamp extends PureComponent {
   };
 
   render () {
-    const { timestamp, intl, statusId } = this.props;
+    const { timestamp, statusId } = this.props;
 
     return (
       <DropdownMenu statusId={statusId} renderItem={this.renderItem} scrollable renderHeader={this.renderHeader} onItemClick={this.handleItemClick}>
         <button className='dropdown-menu__text-button'>
-          <FormattedMessage id='status.edited' defaultMessage='Edited {date}' values={{ date: <span className='animated-number'>{intl.formatDate(timestamp, { month: 'short', day: '2-digit', hour: '2-digit', minute: '2-digit' })}</span> }} />
+          <FormattedMessage id='status.edited' defaultMessage='Edited {date}' values={{ date: <FormattedDateWrapper className='animated-number' value={timestamp} month='short' day='2-digit' hour='2-digit' minute='2-digit' /> }} />
         </button>
       </DropdownMenu>
     );
diff --git a/app/javascript/mastodon/components/formatted_date.tsx b/app/javascript/mastodon/components/formatted_date.tsx
new file mode 100644
index 00000000000..cc927b08737
--- /dev/null
+++ b/app/javascript/mastodon/components/formatted_date.tsx
@@ -0,0 +1,26 @@
+import type { ComponentProps } from 'react';
+
+import { FormattedDate } from 'react-intl';
+
+export const FormattedDateWrapper = (
+  props: ComponentProps<typeof FormattedDate> & { className?: string },
+) => (
+  <FormattedDate {...props}>
+    {(date) => (
+      <time dateTime={tryIsoString(props.value)} className={props.className}>
+        {date}
+      </time>
+    )}
+  </FormattedDate>
+);
+
+const tryIsoString = (date?: string | number | Date): string => {
+  if (!date) {
+    return '';
+  }
+  try {
+    return new Date(date).toISOString();
+  } catch {
+    return date.toString();
+  }
+};
diff --git a/app/javascript/mastodon/features/account_timeline/components/account_header.tsx b/app/javascript/mastodon/features/account_timeline/components/account_header.tsx
index 968224bf791..9505d480109 100644
--- a/app/javascript/mastodon/features/account_timeline/components/account_header.tsx
+++ b/app/javascript/mastodon/features/account_timeline/components/account_header.tsx
@@ -37,6 +37,7 @@ import {
   FollowingCounter,
   StatusesCounter,
 } from 'mastodon/components/counters';
+import { FormattedDateWrapper } from 'mastodon/components/formatted_date';
 import { Icon } from 'mastodon/components/icon';
 import { IconButton } from 'mastodon/components/icon_button';
 import { LoadingIndicator } from 'mastodon/components/loading_indicator';
@@ -938,11 +939,12 @@ export const AccountHeader: React.FC<{
                       />
                     </dt>
                     <dd>
-                      {intl.formatDate(account.created_at, {
-                        year: 'numeric',
-                        month: 'short',
-                        day: '2-digit',
-                      })}
+                      <FormattedDateWrapper
+                        value={account.created_at}
+                        year='numeric'
+                        month='short'
+                        day='2-digit'
+                      />
                     </dd>
                   </dl>
 
diff --git a/app/javascript/mastodon/features/privacy_policy/index.tsx b/app/javascript/mastodon/features/privacy_policy/index.tsx
index f0309c27123..cd6f9f3b2b0 100644
--- a/app/javascript/mastodon/features/privacy_policy/index.tsx
+++ b/app/javascript/mastodon/features/privacy_policy/index.tsx
@@ -1,17 +1,13 @@
 import { useState, useEffect } from 'react';
 
-import {
-  FormattedMessage,
-  FormattedDate,
-  useIntl,
-  defineMessages,
-} from 'react-intl';
+import { FormattedMessage, useIntl, defineMessages } from 'react-intl';
 
 import { Helmet } from 'react-helmet';
 
 import { apiGetPrivacyPolicy } from 'mastodon/api/instance';
 import type { ApiPrivacyPolicyJSON } from 'mastodon/api_types/instance';
 import { Column } from 'mastodon/components/column';
+import { FormattedDateWrapper } from 'mastodon/components/formatted_date';
 import { Skeleton } from 'mastodon/components/skeleton';
 
 const messages = defineMessages({
@@ -58,7 +54,7 @@ const PrivacyPolicy: React.FC<{
                 date: loading ? (
                   <Skeleton width='10ch' />
                 ) : (
-                  <FormattedDate
+                  <FormattedDateWrapper
                     value={response?.updated_at}
                     year='numeric'
                     month='short'
diff --git a/app/javascript/mastodon/features/status/components/detailed_status.tsx b/app/javascript/mastodon/features/status/components/detailed_status.tsx
index 1b605df0671..1291c261596 100644
--- a/app/javascript/mastodon/features/status/components/detailed_status.tsx
+++ b/app/javascript/mastodon/features/status/components/detailed_status.tsx
@@ -6,7 +6,7 @@
 import type { CSSProperties } from 'react';
 import { useState, useRef, useCallback } from 'react';
 
-import { FormattedDate, FormattedMessage } from 'react-intl';
+import { FormattedMessage } from 'react-intl';
 
 import classNames from 'classnames';
 import { Link } from 'react-router-dom';
@@ -16,6 +16,7 @@ import { AnimatedNumber } from 'mastodon/components/animated_number';
 import { ContentWarning } from 'mastodon/components/content_warning';
 import EditedTimestamp from 'mastodon/components/edited_timestamp';
 import { FilterWarning } from 'mastodon/components/filter_warning';
+import { FormattedDateWrapper } from 'mastodon/components/formatted_date';
 import type { StatusLike } from 'mastodon/components/hashtag_bar';
 import { getHashtagBarForStatus } from 'mastodon/components/hashtag_bar';
 import { Icon } from 'mastodon/components/icon';
@@ -388,7 +389,7 @@ export const DetailedStatus: React.FC<{
               target='_blank'
               rel='noopener noreferrer'
             >
-              <FormattedDate
+              <FormattedDateWrapper
                 value={new Date(status.get('created_at') as string)}
                 year='numeric'
                 month='short'