code: public function mapFromForm($value)
      {
          $timeTokens = explode(':', $value);
  
          if (count($timeTokens) === 1) {
              $timeTokens[1] = 0;
          }
  
          return $timeTokens[0] * 60 + $timeTokens[1];
      }
docs: @param mixed $value
  
  @return mixed