private static function _simple_calendar($id, $data, $recurrences, $subject, $message, $diff, $type = "")
 {
     $deliveries_rec = self::_calc_offset($recurrences, $diff);
     $delivery = strtotime($diff, $data["begin"]);
     if (!empty($deliveries_rec)) {
         $delivery = array_shift($deliveries_rec);
     }
     $begin = $data["begin"];
     foreach ($recurrences as $recurrence) {
         if ($recurrence > $delivery) {
             $begin = $recurrence;
             break;
         }
     }
     $message = sprintf($message, modify::recurrences($data["recurs"], array(4, $delivery)));
     $subject = sprintf($subject, modify::shortdatetimeformat($begin));
     db_notification_add("simple_calendar|" . $id . $type, $data["notification"], $subject, $message, $delivery, $deliveries_rec);
 }