hi im using this after record adding page event
$creditdays=$data2["creditdays"];
echo $creditdays;
$invdate=$data1["Inv_Date"];
echo $invdate;
$newdate = strtotime ( '".$creditdays." day' , strtotime ( $invdate ) ) ;
$newdate = date ( 'Y-m-j' , $newdate );
im getting $newdate as a 1970-1-1
plz help me to solve this problem