CFG->nofixday can override the ficing of day format in userdate

config-dist.php

@@ -199,6 +199,10 @@ $CFG->admin = 'admin';
 // settings. Use this if you want to control session configuration
 // from php.ini, httpd.conf or .htaccess files. 
 //      $CFG->respectsessionsettings = true;
+//
+// This setting will cause the userdate() function not to fix %d in 
+// date strings, and just let them show with a zero prefix.
+//      $CFG->nofixday = true;
 
 //=========================================================================
 // ALL DONE!  To continue installation, visit your main page with a browser

lib/moodlelib.php

@@ -691,13 +691,19 @@ function make_timestamp($year, $month=1, $day=1, $hour=0, $minute=0, $second=0,
  */
 function userdate($date, $format='', $timezone=99, $fixday = true) {
 
+    global $CFG;
+
+    static $strftimedaydatetime;
 
     if ($format == '') {
-        $format = get_string('strftimedaydatetime');
+        if (empty($strftimedaydatetime)) {
+            $strftimedaydatetime = get_string('strftimedaydatetime');
+        }
+        $format = $strftimedaydatetime;
     }
 
     $formatnoday = str_replace('%d', 'DD', $format);
-    if ($fixday) {
+    if ($fixday and empty($CFG->nofixday)) {    // Config.php can force %d not to be fixed.
         $fixday = ($formatnoday != $format);
     }