private function formatH(&$str) {
    if (strstr($str, '%H'))
      $str = str_replace('%H', sprintf('%02d', $this->hour), $str);
  }
private function formatH(&$str) {
    if (strstr($str, '%H'))
      $str = str_replace('%H', sprintf('%02d', $this->hour), $str);
  }
private function formatH ( & $ str ) { if ( strstr ( $ str , '%H' ) ) $ str = str_replace ( '%H' , sprintf ( '%02d' , $ this -> hour ) , $ str ) ; }
24-hour format of an hour with leading zeros
@param type $str
24 - hour format of an hour with leading zeros