PHP--两个字符串日期相减得到日时分秒

  原出处：http://www.cnblogs.com/wang1204/p/5670920.html

  //功能：计算两个时间戳之间相差的日时分秒

   //$begin_time 开始时间戳
   //$end_time 结束时间戳

	function timediff($begin_time,$end_time)
      {
	  if($begin_time < $end_time){
	     $starttime = $begin_time;
	     $endtime = $end_time;
          }else{
	     $starttime = $end_time;
	     $endtime = $begin_time;
        }


	  //计算天数
	  $timediff = $endtime-$starttime;
	  $days = intval($timediff/86400);
	  //计算小时数
	  $remain = $timediff%86400;
	  $hours = intval($remain/3600);
	  //计算分钟数
	  $remain = $remain%3600;
	  $mins = intval($remain/60);
	  //计算秒数
	  $secs = $remain%60;
	  $res = array("day" => $days,"hour" => $hours,"min" => $mins,"sec" => $secs);
	  return $res;
       }


	print_r(timediff(strtotime(2015-03-20 16:20:30'),strtotime('2015-05-25 11:10:10')));