=== modified file 'sites/all/modules/backup_migrate/backup_migrate.module'
--- sites/all/modules/backup_migrate/backup_migrate.module	2010-07-19 14:38:36 +0000
+++ sites/all/modules/backup_migrate/backup_migrate.module	2010-07-19 14:39:05 +0000
@@ -620,7 +620,7 @@
   }
 
   if ($settings->append_timestamp && $settings->timestamp_format) {
-    $settings->filename .= "-". date($settings->timestamp_format);
+    $settings->filename .= "-". format_date(time(), 'custom', $settings->timestamp_format);
   }
   $settings->filename = _backup_migrate_clean_filename($settings->filename);