private function formatG(&$str) {
    if (strstr($str, '%G'))
      $str = str_replace('%G', sprintf('%1d', $this->hour), $str);
  }
private function formatG(&$str) {
    if (strstr($str, '%G'))
      $str = str_replace('%G', sprintf('%1d', $this->hour), $str);
  }
24-hour format of an hour without leading zeros
@param type $str