diff --git a/core/misc/date.js b/core/misc/date.js
index 8b6b71cb1d..f0c8c3823f 100644
--- a/core/misc/date.js
+++ b/core/misc/date.js
@@ -36,6 +36,24 @@
           .replace('Y', 'yy')
           .replace('m', 'mm')
           .replace('d', 'dd');
+
+        // If the date format isn't the standard HTML5 one, we need to use
+        // jQuery altField mecanism to ensure data get sent in the correct
+        // format.
+        if (datepickerSettings.dateFormat != 'yy-mm-dd') {
+          var $hidden = $('<input type="hidden" />');
+          $hidden.attr('name', $input.attr('name'));
+          $hidden.val($input.val());
+          $input.attr('name', '');
+          $input.parent().append($hidden);
+          datepickerSettings.altFormat = 'yy-mm-dd';
+          datepickerSettings.altField = $hidden;
+          if ($input.val()) {
+            var localized = $.datepicker.formatDate(datepickerSettings.dateFormat, new Date($input.val()));
+            $input.val(localized);
+          }
+        }
+
         // Add min and max date if set on the input.
         if ($input.attr('min')) {
           datepickerSettings.minDate = $input.attr('min');