diff --git a/includes/form.inc b/includes/form.inc
index d170a1a910ef63616ecad3b18c8117860f1e66e4..9799aeca00f8eca5426e9d902294826fafe4fdcd 100644
--- a/includes/form.inc
+++ b/includes/form.inc
@@ -1716,7 +1716,21 @@ function date_validate($form) {
  * Helper function for usage with drupal_map_assoc to display month names.
  */
 function map_month($month) {
-  return format_date(gmmktime(0, 0, 0, $month, 2, 1970), 'custom', 'M', 0);
+  static $months = array(
+    1 => 'Jan',
+    2 => 'Feb',
+    3 => 'Mar',
+    4 => 'Apr',
+    5 => 'May',
+    6 => 'Jun',
+    7 => 'Jul',
+    8 => 'Aug',
+    9 => 'Sep',
+    10 => 'Oct',
+    11 => 'Nov',
+    12 => 'Dec',
+  );
+  return t($months[$month]);
 }
 
 /**