if (isset($_REQUEST['buildup_start_date']) && $_REQUEST['buildup_start_date'] != '') {
      if (DateTime::createFromFormat("Y-m-d", trim($_REQUEST['buildup_start_date']))) {
        $buildup_start_date = DateTime::createFromFormat("Y-m-d", trim($_REQUEST['buildup_start_date']))->getTimestamp();
      } else {
          $ok = false;