計算兩個時間戳之間的時間差

    //功能：計算兩個時間戳之間相差的日時分秒
    //$begin_time  開始時間戳
    //$end_time 結束時間戳

    private function timediff($begin_time,$end_time)
    {
    	if($begin_time < $end_time){
    		$starttime = $begin_time;
    		$endtime = $end_time;
    	}else{
    		$starttime = $end_time;
    		$endtime = $begin_time;
    	}
    
    	//計算天數
    	$timediff = $endtime-$starttime;
    	$days = intval($timediff/86400);
    	//計算小時數
    	//$remain = $timediff%86400;取消註釋後下一行的變量改爲$remain，則是去掉天數後剩餘的小時數，分鐘及描述同理
    	$hours = intval($timediff/3600);
    	//計算分鐘數
    	//$remain = $remain%3600;
    	$mins = intval($timediff/60);
    	//計算秒數
    	$secs = $timediff%60;
    	$res = array("day" => $days,"hour" => $hours,"min" => $mins,"sec" => $secs);
    	return $res;
    }