Sample Datediff

<?php
function xTimeAgo ($oldTime, $newTime, $timeType) {
        $timeCalc = strtotime($newTime) - strtotime($oldTime);
        if ($timeType == "x") {
            if ($timeCalc = 60) {
                $timeType = "m";
            }
            if ($timeCalc = (60*60)) {
                $timeType = "h";
            }
            if ($timeCalc = (60*60*24)) {
                $timeType = "d";
            }
        }
    //detik
        if ($timeType == "s") {
            $timeCalc .= $timeCalc;
        }
    //menit
        if ($timeType == "m") {
            $timeCalc = round($timeCalc/60);
        }
    //jam
        if ($timeType == "h") {
            $timeCalc = round($timeCalc/60/60);
        }
    //hari
        if ($timeType == "d") {
            $timeCalc = round($timeCalc/60/60/24);
        }
        return $timeCalc;
    }
$sekarang=date("Y-m-d H:i:s");
$dulu=date("Y-m-d")." 04:00:00";
$durasi="2";
$diff=xTimeAgo($sekarang,$dulu,"h");
if($diff > $durasi)
{
    echo "LEWAT";
}else{
    echo "BELUM LEWAT";
}
?>