diff --git a/js/src/datetimepicker.js b/js/src/datetimepicker.js
index 8ed4a2bfaa..4a019be3c9 100644
--- a/js/src/datetimepicker.js
+++ b/js/src/datetimepicker.js
@@ -85,6 +85,9 @@ function registerTimePickerTranslations () {
     $.timepicker.regional[''].hourText = window.Messages.strCalendarHour;
     $.timepicker.regional[''].minuteText = window.Messages.strCalendarMinute;
     $.timepicker.regional[''].secondText = window.Messages.strCalendarSecond;
+    $.timepicker.regional[''].millisecText = window.Messages.strCalendarMillisecond;
+    $.timepicker.regional[''].microsecText = window.Messages.strCalendarMicrosecond;
+    $.timepicker.regional[''].timezoneText = window.Messages.strCalendarTimezone;
 
     // eslint-disable-next-line no-underscore-dangle
     $.extend($.timepicker._defaults, $.timepicker.regional['']);
diff --git a/libraries/classes/Controllers/JavaScriptMessagesController.php b/libraries/classes/Controllers/JavaScriptMessagesController.php
index f6713b2c4f..02678caff4 100644
--- a/libraries/classes/Controllers/JavaScriptMessagesController.php
+++ b/libraries/classes/Controllers/JavaScriptMessagesController.php
@@ -714,118 +714,68 @@ final class JavaScriptMessagesController
             'strShow' => __('Show'),
             'strStructure' => __('Structure'),
 
-            /* DateTime Picker */
-            // l10n: Month name
-            'strMonthNameJan' => __('January'),
-            // l10n: Month name
-            'strMonthNameFeb' => __('February'),
-            // l10n: Month name
-            'strMonthNameMar' => __('March'),
-            // l10n: Month name
-            'strMonthNameApr' => __('April'),
-            // l10n: Month name
-            'strMonthNameMay' => __('May'),
-            // l10n: Month name
-            'strMonthNameJun' => __('June'),
-            // l10n: Month name
-            'strMonthNameJul' => __('July'),
-            // l10n: Month name
-            'strMonthNameAug' => __('August'),
-            // l10n: Month name
-            'strMonthNameSep' => __('September'),
-            // l10n: Month name
-            'strMonthNameOct' => __('October'),
-            // l10n: Month name
-            'strMonthNameNov' => __('November'),
-            // l10n: Month name
-            'strMonthNameDec' => __('December'),
-            /* l10n: Short month name for January */
-            'strMonthNameJanShort' => __('Jan'),
-            /* l10n: Short month name for February */
-            'strMonthNameFebShort' => __('Feb'),
-            /* l10n: Short month name for March */
-            'strMonthNameMarShort' => __('Mar'),
-            /* l10n: Short month name for April */
-            'strMonthNameAprShort' => __('Apr'),
-            /* l10n: Short month name for May */
-            'strMonthNameMayShort' => __('May'),
-            /* l10n: Short month name for June */
-            'strMonthNameJunShort' => __('Jun'),
-            /* l10n: Short month name for July */
-            'strMonthNameJulShort' => __('Jul'),
-            /* l10n: Short month name for August */
-            'strMonthNameAugShort' => __('Aug'),
-            /* l10n: Short month name for September */
-            'strMonthNameSepShort' => __('Sep'),
-            /* l10n: Short month name for October */
-            'strMonthNameOctShort' => __('Oct'),
-            /* l10n: Short month name for November */
-            'strMonthNameNovShort' => __('Nov'),
-            /* l10n: Short month name for December */
-            'strMonthNameDecShort' => __('Dec'),
-            /* l10n: Week day name */
-            'strDayNameSun' => __('Sunday'),
-            /* l10n: Week day name */
-            'strDayNameMon' => __('Monday'),
-            /* l10n: Week day name */
-            'strDayNameTue' => __('Tuesday'),
-            /* l10n: Week day name */
-            'strDayNameWed' => __('Wednesday'),
-            /* l10n: Week day name */
-            'strDayNameThu' => __('Thursday'),
-            /* l10n: Week day name */
-            'strDayNameFri' => __('Friday'),
-            /* l10n: Week day name */
-            'strDayNameSat' => __('Saturday'),
-            /* l10n: Short week day name for Sunday */
-            'strDayNameSunShort' => __('Sun'),
-            /* l10n: Short week day name for Monday */
-            'strDayNameMonShort' => __('Mon'),
-            /* l10n: Short week day name for Tuesday */
-            'strDayNameTueShort' => __('Tue'),
-            /* l10n: Short week day name for Wednesday */
-            'strDayNameWedShort' => __('Wed'),
-            /* l10n: Short week day name for Thursday */
-            'strDayNameThuShort' => __('Thu'),
-            /* l10n: Short week day name for Friday */
-            'strDayNameFriShort' => __('Fri'),
-            /* l10n: Short week day name for Saturday */
-            'strDayNameSatShort' => __('Sat'),
-            /* l10n: Minimal week day name for Sunday */
-            'strDayNameSunMin' => __('Su'),
-            /* l10n: Minimal week day name for Monday */
-            'strDayNameMonMin' => __('Mo'),
-            /* l10n: Minimal week day name for Tuesday */
-            'strDayNameTueMin' => __('Tu'),
-            /* l10n: Minimal week day name for Wednesday */
-            'strDayNameWedMin' => __('We'),
-            /* l10n: Minimal week day name for Thursday */
-            'strDayNameThuMin' => __('Th'),
-            /* l10n: Minimal week day name for Friday */
-            'strDayNameFriMin' => __('Fr'),
-            /* l10n: Minimal week day name for Saturday */
-            'strDayNameSatMin' => __('Sa'),
-            /* l10n: Column header for week of the year in calendar */
-            'strWeekHeader' => __('Wk'),
-            // phpcs:ignore Generic.Files.LineLength.TooLong
-            /* l10n: The month-year order in a calendar. Do not translate! Use either "calendar-month-year" or "calendar-year-month". */
-            'strMonthAfterYear' => __('calendar-month-year'),
-            /* l10n: Year suffix for calendar, "none" is empty. */
-            'strYearSuffix' => __('none'),
-            /* l10n: A specific point in the day, as shown on a clock. */
-            'strCalendarTime' => __('Time'),
-            /* l10n: Period of time. */
-            'strCalendarHour' => __('Hour'),
-            /* l10n: Period of time. */
-            'strCalendarMinute' => __('Minute'),
-            /* l10n: Period of time. */
-            'strCalendarSecond' => __('Second'),
+            'strMonthNameJan' => _pgettext('Month name', 'January'),
+            'strMonthNameFeb' => _pgettext('Month name', 'February'),
+            'strMonthNameMar' => _pgettext('Month name', 'March'),
+            'strMonthNameApr' => _pgettext('Month name', 'April'),
+            'strMonthNameMay' => _pgettext('Month name', 'May'),
+            'strMonthNameJun' => _pgettext('Month name', 'June'),
+            'strMonthNameJul' => _pgettext('Month name', 'July'),
+            'strMonthNameAug' => _pgettext('Month name', 'August'),
+            'strMonthNameSep' => _pgettext('Month name', 'September'),
+            'strMonthNameOct' => _pgettext('Month name', 'October'),
+            'strMonthNameNov' => _pgettext('Month name', 'November'),
+            'strMonthNameDec' => _pgettext('Month name', 'December'),
+            'strMonthNameJanShort' => _pgettext('Short month name for January', 'Jan'),
+            'strMonthNameFebShort' => _pgettext('Short month name for February', 'Feb'),
+            'strMonthNameMarShort' => _pgettext('Short month name for March', 'Mar'),
+            'strMonthNameAprShort' => _pgettext('Short month name for April', 'Apr'),
+            'strMonthNameMayShort' => _pgettext('Short month name for May', 'May'),
+            'strMonthNameJunShort' => _pgettext('Short month name for June', 'Jun'),
+            'strMonthNameJulShort' => _pgettext('Short month name for July', 'Jul'),
+            'strMonthNameAugShort' => _pgettext('Short month name for August', 'Aug'),
+            'strMonthNameSepShort' => _pgettext('Short month name for September', 'Sep'),
+            'strMonthNameOctShort' => _pgettext('Short month name for October', 'Oct'),
+            'strMonthNameNovShort' => _pgettext('Short month name for November', 'Nov'),
+            'strMonthNameDecShort' => _pgettext('Short month name for December', 'Dec'),
+            'strDayNameSun' => _pgettext('Week day name', 'Sunday'),
+            'strDayNameMon' => _pgettext('Week day name', 'Monday'),
+            'strDayNameTue' => _pgettext('Week day name', 'Tuesday'),
+            'strDayNameWed' => _pgettext('Week day name', 'Wednesday'),
+            'strDayNameThu' => _pgettext('Week day name', 'Thursday'),
+            'strDayNameFri' => _pgettext('Week day name', 'Friday'),
+            'strDayNameSat' => _pgettext('Week day name', 'Saturday'),
+            'strDayNameSunShort' => _pgettext('Short week day name for Sunday', 'Sun'),
+            'strDayNameMonShort' => _pgettext('Short week day name for Monday', 'Mon'),
+            'strDayNameTueShort' => _pgettext('Short week day name for Tuesday', 'Tue'),
+            'strDayNameWedShort' => _pgettext('Short week day name for Wednesday', 'Wed'),
+            'strDayNameThuShort' => _pgettext('Short week day name for Thursday', 'Thu'),
+            'strDayNameFriShort' => _pgettext('Short week day name for Friday', 'Fri'),
+            'strDayNameSatShort' => _pgettext('Short week day name for Saturday', 'Sat'),
+            'strDayNameSunMin' => _pgettext('Minimal week day name for Sunday', 'Su'),
+            'strDayNameMonMin' => _pgettext('Minimal week day name for Monday', 'Mo'),
+            'strDayNameTueMin' => _pgettext('Minimal week day name for Tuesday', 'Tu'),
+            'strDayNameWedMin' => _pgettext('Minimal week day name for Wednesday', 'We'),
+            'strDayNameThuMin' => _pgettext('Minimal week day name for Thursday', 'Th'),
+            'strDayNameFriMin' => _pgettext('Minimal week day name for Friday', 'Fr'),
+            'strDayNameSatMin' => _pgettext('Minimal week day name for Saturday', 'Sa'),
+            'strWeekHeader' => _pgettext('Column header for week of the year in calendar', 'Wk'),
+            /* l10n: DO NOT TRANSLATE! Use either "calendar-month-year" or "calendar-year-month". */
+            'strMonthAfterYear' => _pgettext('The month-year order in a calendar', 'calendar-month-year'),
+            'strYearSuffix' => _pgettext('Year suffix for calendar, "none" is empty', 'none'),
+            'strCalendarTime' => _pgettext('A specific point in the day, as shown on a clock', 'Time'),
+            'strCalendarHour' => _pgettext('Unit of time', 'Hour'),
+            'strCalendarMinute' => _pgettext('Unit of time', 'Minute'),
+            'strCalendarSecond' => _pgettext('Unit of time', 'Second'),
+            'strCalendarMillisecond' => _pgettext('Unit of time', 'Millisecond'),
+            'strCalendarMicrosecond' => _pgettext('Unit of time', 'Microsecond'),
+            'strCalendarTimezone' => _pgettext('The time zone for a time of day', 'Time zone'),
             /* l10n: Display text for calendar close link */
             'strCalendarClose' => __('Done'),
-            /* l10n: Previous month. Display text for previous month link in calendar */
-            'strCalendarPrevious' => __('Prev'),
-            /* l10n: Next month. Display text for next month link in calendar */
-            'strCalendarNext' => __('Next'),
+            /* l10n: Display text for previous month link in calendar */
+            'strCalendarPrevious' => _pgettext('Previous month', 'Prev'),
+            /* l10n: Display text for next month link in calendar */
+            'strCalendarNext' => _pgettext('Next month', 'Next'),
             /* l10n: Display text for current month link in calendar */
             'strCalendarCurrent' => __('Today'),
 
diff --git a/libraries/classes/Util.php b/libraries/classes/Util.php
index de4f367f00..f43e726fde 100644
--- a/libraries/classes/Util.php
+++ b/libraries/classes/Util.php
@@ -618,46 +618,27 @@ class Util
     public static function localisedDate($timestamp = -1, $format = ''): string
     {
         $month = [
-            /* l10n: Short month name */
-            __('Jan'),
-            /* l10n: Short month name */
-            __('Feb'),
-            /* l10n: Short month name */
-            __('Mar'),
-            /* l10n: Short month name */
-            __('Apr'),
-            /* l10n: Short month name */
-            _pgettext('Short month name', 'May'),
-            /* l10n: Short month name */
-            __('Jun'),
-            /* l10n: Short month name */
-            __('Jul'),
-            /* l10n: Short month name */
-            __('Aug'),
-            /* l10n: Short month name */
-            __('Sep'),
-            /* l10n: Short month name */
-            __('Oct'),
-            /* l10n: Short month name */
-            __('Nov'),
-            /* l10n: Short month name */
-            __('Dec'),
+            _pgettext('Short month name for January', 'Jan'),
+            _pgettext('Short month name for February', 'Feb'),
+            _pgettext('Short month name for March', 'Mar'),
+            _pgettext('Short month name for April', 'Apr'),
+            _pgettext('Short month name for May', 'May'),
+            _pgettext('Short month name for June', 'Jun'),
+            _pgettext('Short month name for July', 'Jul'),
+            _pgettext('Short month name for August', 'Aug'),
+            _pgettext('Short month name for September', 'Sep'),
+            _pgettext('Short month name for October', 'Oct'),
+            _pgettext('Short month name for November', 'Nov'),
+            _pgettext('Short month name for December', 'Dec'),
         ];
         $dayOfWeek = [
-            /* l10n: Short week day name for Sunday */
             _pgettext('Short week day name for Sunday', 'Sun'),
-            /* l10n: Short week day name for Monday */
-            __('Mon'),
-            /* l10n: Short week day name for Tuesday */
-            __('Tue'),
-            /* l10n: Short week day name for Wednesday */
-            __('Wed'),
-            /* l10n: Short week day name for Thursday */
-            __('Thu'),
-            /* l10n: Short week day name for Friday */
-            __('Fri'),
-            /* l10n: Short week day name for Saturday */
-            __('Sat'),
+            _pgettext('Short week day name for Monday', 'Mon'),
+            _pgettext('Short week day name for Tuesday', 'Tue'),
+            _pgettext('Short week day name for Wednesday', 'Wed'),
+            _pgettext('Short week day name for Thursday', 'Thu'),
+            _pgettext('Short week day name for Friday', 'Fri'),
+            _pgettext('Short week day name for Saturday', 'Sat'),
         ];
 
         if ($format == '') {