PHP相隔年、月、日函数，很简洁的哦~~

function DiffDate($date,$day=0,$month=0,$year=0){
$DArr=split('-',$date);
if(checkdate($DArr[1],$DArr[2],$DArr[0])){
    $stdate=strtotime($date);
    return date('Y-m-d', mktime(0,0,0,date("m",$stdate)+$month, date("d",$stdate)+$day, date("Y",$stdate)+$year));
}
}