code: public function getMonth()
      {
          if ($this->value !== null) {
              preg_match('/^(?P<year>[0-9]{4,4})-(?P<month>[0-9]{2,2})-(?P<day>[0-9]{2,2}) (?P<hour>[0-9]{2,2}):(?P<minute>[0-9]{2,2}):(?P<second>[0-9]{2,2})$/ui', $this->value, $m);
              return (int) $m['month'];
          }
      }
docs: Returns the month
  
  @return int|null