Mind the oxford comma

app/assets/javascripts/pages/users/user_tabs.js

@@ -221,7 +221,7 @@ export default class UserTabs {
     const monthsAgo = UserTabs.getVisibleCalendarPeriod($calendarWrap);
     const calendarActivitiesPath = $calendarWrap.data('calendarActivitiesPath');
     const utcOffset = $calendarWrap.data('utcOffset');
-    const calendarHint = __('Issues, merge requests, pushes and comments.');
+    const calendarHint = __('Issues, merge requests, pushes, and comments.');
 
     $calendarWrap.html(CALENDAR_TEMPLATE);
 

locale/gitlab.pot

@@ -5415,7 +5415,7 @@ msgstr ""
 msgid "Issues closed"
 msgstr ""
 
-msgid "Issues, merge requests, pushes and comments."
+msgid "Issues, merge requests, pushes, and comments."
 msgstr ""
 
 msgid "IssuesAnalytics|After you begin creating issues for your projects, we can start tracking and displaying metrics for them"