Función similar al datediff de VB PHP

/**
   *
   *
   * @static
   * @param string $interval Tipo de Comparación.
   * @param date $dateTimeBegin Fecha Inicial.
   * @param date $dateTimeEnd Fecha Final.
   * @return string Diferencia
   */
  public static function dateDiff($interval,$dateTimeBegin,$dateTimeEnd) {
    //Parse about any English textual datetime
    //$dateTimeBegin, $dateTimeEnd

    $dateTimeBegin=strtotime($dateTimeBegin);
    if($dateTimeBegin === -1) {
      return("..begin date Invalid");
    }

    $dateTimeEnd=strtotime($dateTimeEnd);
    if($dateTimeEnd === -1) {
      return("..end date Invalid");
    }

    $dif=$dateTimeEnd - $dateTimeBegin;

    switch($interval) {
      case "s"://seconds
        return($dif);

      case "n"://minutes
        return(floor($dif/60)); //60s=1m

      case "h"://hours
        return(floor($dif/3600)); //3600s=1h

      case "d"://days
        return(floor($dif/86400)); //86400s=1d

      case "ww"://Week
        return(floor($dif/604800)); //604800s=1week=1semana

      case "m": //similar result "m" dateDiff Microsoft
        $monthBegin=(date("Y",$dateTimeBegin)*12)+
        date("n",$dateTimeBegin);
        $monthEnd=(date("Y",$dateTimeEnd)*12)+
        date("n",$dateTimeEnd);
        $monthDiff=$monthEnd-$monthBegin;
        return($monthDiff);

      case "yyyy": //similar result "yyyy" dateDiff Microsoft
        return(date("Y",$dateTimeEnd) - date("Y",$dateTimeBegin));

      default:
        return(floor($dif/86400)); //86400s=1d
    }

  }