php 获取时间差

function timediff($begin_time,$end_time)
{
     if($begin_time < $end_time){
        $starttime = $begin_time;
        $endtime = $end_time;
     }
     else{
        $starttime = $end_time;
        $endtime = $begin_time;
     }
     $timediff = $endtime-$starttime;
     $days = intval($timediff/86400);
     $remain = $timediff%86400;
     $hours = intval($remain/3600);
     $remain = $remain%3600;
     $mins = intval($remain/60);
     $secs = $remain%60;
     $res = array("day" => $days,"hour" => $hours,"min" => $mins,"sec" => $secs);
     return $res;
}