diff --git a/core/modules/locale/locale.datepicker.es6.js b/core/modules/locale/locale.datepicker.es6.js
index 7704fc3554..ffa744b9e4 100644
--- a/core/modules/locale/locale.datepicker.es6.js
+++ b/core/modules/locale/locale.datepicker.es6.js
@@ -74,7 +74,9 @@
           Drupal.t('Fr'),
           Drupal.t('Sa'),
         ],
-        dateFormat: Drupal.t('mm/dd/yy'),
+        // For a full list of the possible formats see the formatDate function.
+        // @see: http://api.jqueryui.com/datepicker/#utility-formatDate
+        dateFormat: 'mm/dd/yy',
         firstDay: 0,
         isRTL: 0,
       }, drupalSettings.jquery.ui.datepicker);
diff --git a/core/modules/locale/locale.datepicker.js b/core/modules/locale/locale.datepicker.js
index 927bbc8e92..1713916c70 100644
--- a/core/modules/locale/locale.datepicker.js
+++ b/core/modules/locale/locale.datepicker.js
@@ -18,7 +18,8 @@
         dayNames: [Drupal.t('Sunday'), Drupal.t('Monday'), Drupal.t('Tuesday'), Drupal.t('Wednesday'), Drupal.t('Thursday'), Drupal.t('Friday'), Drupal.t('Saturday')],
         dayNamesShort: [Drupal.t('Sun'), Drupal.t('Mon'), Drupal.t('Tue'), Drupal.t('Wed'), Drupal.t('Thu'), Drupal.t('Fri'), Drupal.t('Sat')],
         dayNamesMin: [Drupal.t('Su'), Drupal.t('Mo'), Drupal.t('Tu'), Drupal.t('We'), Drupal.t('Th'), Drupal.t('Fr'), Drupal.t('Sa')],
-        dateFormat: Drupal.t('mm/dd/yy'),
+
+        dateFormat: 'mm/dd/yy',
         firstDay: 0,
         isRTL: 0
       }, drupalSettings.jquery.ui.datepicker);