Public Function DateAdd($Per,$N,$Date,$Type){
$Per = Strtolower($Per);
$Date = Strtotime($Date);
Switch ($Per){
Case "y" : $N*=12;
Case "m" : $Date = Mktime(Date("H",$Date),Date("i",$Date),Date("s",$Date),Date("n",$Date)+$N,Date("j",$Date),Date("Y",$Date));
$N = 0; Break;
Case "w" : $N*=7;
Case "d" : $N*=24;
Case "h" : $N*=60;
Case "n" : $N*=60;
}
Return Date($Type , $Date + $N);
}أرجو مساعدتي لتحويل هذا الفنكشن الى التاريخ الهجري