Index: office_hours.elements.inc
===================================================================
--- office_hours.elements.inc	(revision 396)
+++ office_hours.elements.inc	(working copy)
@@ -112,13 +112,13 @@
   $element['hours'] = array(
     '#type' => 'select',
     '#options' => drupal_map_assoc($hours),
-    '#default_value' => isset($defhr) ? $defhr : 0,
+    '#default_value' => $defhr != '' ? (!$element['#hoursformat'] ? str_pad($defhr, 2, '0', STR_PAD_LEFT) : $defhr) : 0,
   );
 
   $element['minutes'] = array(
     '#type' => 'select',
     '#options' => drupal_map_assoc($minutes),
-    '#default_value' => isset($defmin) ? $defmin : '',
+    '#default_value' => $defmin != '' ? str_pad($defmin, 2, '0', STR_PAD_LEFT) : '',
   );
   if ($element['#hoursformat'] == 1) {
     $element['ampm'] = array(