diff --git a/app/javascript/mastodon/components/edited_timestamp/index.jsx b/app/javascript/mastodon/components/edited_timestamp/index.jsx
index 4ca00f8dda..7b70f9d6e1 100644
--- a/app/javascript/mastodon/components/edited_timestamp/index.jsx
+++ b/app/javascript/mastodon/components/edited_timestamp/index.jsx
@@ -67,7 +67,7 @@ class EditedTimestamp extends PureComponent {
     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: intl.formatDate(timestamp, { hour12: false, month: 'short', day: '2-digit', hour: '2-digit', minute: '2-digit' }) }} /> <Icon id='caret-down' icon={ArrowDropDownIcon} />
+          <FormattedMessage id='status.edited' defaultMessage='Edited {date}' values={{ date: intl.formatDate(timestamp, { month: 'short', day: '2-digit', hour: '2-digit', minute: '2-digit' }) }} /> <Icon id='caret-down' icon={ArrowDropDownIcon} />
         </button>
       </DropdownMenu>
     );
diff --git a/app/javascript/mastodon/components/relative_timestamp.tsx b/app/javascript/mastodon/components/relative_timestamp.tsx
index ac3ab0fb4d..12530c2b17 100644
--- a/app/javascript/mastodon/components/relative_timestamp.tsx
+++ b/app/javascript/mastodon/components/relative_timestamp.tsx
@@ -53,7 +53,6 @@ const messages = defineMessages({
 });
 
 const dateFormatOptions = {
-  hour12: false,
   year: 'numeric',
   month: 'short',
   day: '2-digit',
diff --git a/app/javascript/mastodon/components/status.jsx b/app/javascript/mastodon/components/status.jsx
index 1171351c51..be9a1cec65 100644
--- a/app/javascript/mastodon/components/status.jsx
+++ b/app/javascript/mastodon/components/status.jsx
@@ -554,7 +554,7 @@ class Status extends ImmutablePureComponent {
             <div onClick={this.handleClick} className='status__info'>
               <a href={`/@${status.getIn(['account', 'acct'])}/${status.get('id')}`} className='status__relative-time' target='_blank' rel='noopener noreferrer'>
                 <span className='status__visibility-icon'><VisibilityIcon visibility={status.get('visibility')} /></span>
-                <RelativeTimestamp timestamp={status.get('created_at')} />{status.get('edited_at') && <abbr title={intl.formatMessage(messages.edited, { date: intl.formatDate(status.get('edited_at'), { hour12: false, year: 'numeric', month: 'short', day: '2-digit', hour: '2-digit', minute: '2-digit' }) })}> *</abbr>}
+                <RelativeTimestamp timestamp={status.get('created_at')} />{status.get('edited_at') && <abbr title={intl.formatMessage(messages.edited, { date: intl.formatDate(status.get('edited_at'), { year: 'numeric', month: 'short', day: '2-digit', hour: '2-digit', minute: '2-digit' }) })}> *</abbr>}
               </a>
 
               <a onClick={this.handleAccountClick} href={`/@${status.getIn(['account', 'acct'])}`} title={status.getIn(['account', 'acct'])} className='status__display-name' target='_blank' rel='noopener noreferrer'>
diff --git a/app/javascript/mastodon/features/account/components/header.jsx b/app/javascript/mastodon/features/account/components/header.jsx
index 233d208c64..07ea227c48 100644
--- a/app/javascript/mastodon/features/account/components/header.jsx
+++ b/app/javascript/mastodon/features/account/components/header.jsx
@@ -101,7 +101,6 @@ const dateFormatOptions = {
   month: 'short',
   day: 'numeric',
   year: 'numeric',
-  hour12: false,
   hour: '2-digit',
   minute: '2-digit',
 };
diff --git a/app/javascript/mastodon/features/getting_started/components/announcements.jsx b/app/javascript/mastodon/features/getting_started/components/announcements.jsx
index ea36cefd7d..3c0b53b9e7 100644
--- a/app/javascript/mastodon/features/getting_started/components/announcements.jsx
+++ b/app/javascript/mastodon/features/getting_started/components/announcements.jsx
@@ -343,7 +343,7 @@ class Announcement extends ImmutablePureComponent {
       <div className='announcements__item'>
         <strong className='announcements__item__range'>
           <FormattedMessage id='announcement.announcement' defaultMessage='Announcement' />
-          {hasTimeRange && <span> · <FormattedDate value={startsAt} hour12={false} year={(skipYear || startsAt.getFullYear() === now.getFullYear()) ? undefined : 'numeric'} month='short' day='2-digit' hour={skipTime ? undefined : '2-digit'} minute={skipTime ? undefined : '2-digit'} /> - <FormattedDate value={endsAt} hour12={false} year={(skipYear || endsAt.getFullYear() === now.getFullYear()) ? undefined : 'numeric'} month={skipEndDate ? undefined : 'short'} day={skipEndDate ? undefined : '2-digit'} hour={skipTime ? undefined : '2-digit'} minute={skipTime ? undefined : '2-digit'} /></span>}
+          {hasTimeRange && <span> · <FormattedDate value={startsAt} year={(skipYear || startsAt.getFullYear() === now.getFullYear()) ? undefined : 'numeric'} month='short' day='2-digit' hour={skipTime ? undefined : '2-digit'} minute={skipTime ? undefined : '2-digit'} /> - <FormattedDate value={endsAt} year={(skipYear || endsAt.getFullYear() === now.getFullYear()) ? undefined : 'numeric'} month={skipEndDate ? undefined : 'short'} day={skipEndDate ? undefined : '2-digit'} hour={skipTime ? undefined : '2-digit'} minute={skipTime ? undefined : '2-digit'} /></span>}
         </strong>
 
         <Content announcement={announcement} />
diff --git a/app/javascript/mastodon/features/status/components/detailed_status.jsx b/app/javascript/mastodon/features/status/components/detailed_status.jsx
index 437e9e86bf..d10c8966e4 100644
--- a/app/javascript/mastodon/features/status/components/detailed_status.jsx
+++ b/app/javascript/mastodon/features/status/components/detailed_status.jsx
@@ -311,7 +311,7 @@ class DetailedStatus extends ImmutablePureComponent {
 
           <div className='detailed-status__meta'>
             <a className='detailed-status__datetime' href={`/@${status.getIn(['account', 'acct'])}/${status.get('id')}`} target='_blank' rel='noopener noreferrer'>
-              <FormattedDate value={new Date(status.get('created_at'))} hour12={false} year='numeric' month='short' day='2-digit' hour='2-digit' minute='2-digit' />
+              <FormattedDate value={new Date(status.get('created_at'))} year='numeric' month='short' day='2-digit' hour='2-digit' minute='2-digit' />
             </a>{edited}{visibilityLink}{applicationLink}{reblogLink} · {favouriteLink}
           </div>
         </div>
diff --git a/app/javascript/packs/public.jsx b/app/javascript/packs/public.jsx
index 01b57dce39..d8a4c16034 100644
--- a/app/javascript/packs/public.jsx
+++ b/app/javascript/packs/public.jsx
@@ -65,7 +65,6 @@ function loaded() {
 
   const timeFormat = new Intl.DateTimeFormat(locale, {
     timeStyle: 'short',
-    hour12: false,
   });
 
   const formatMessage = ({ id, defaultMessage }, values) => {