php 傻瓜式代码计算两个时间间隔

$stamp = (strtotime($_POST['start'])-strtotime($_POST['end']));
$s = $stamp%60; //秒
$m_stamp= ($stamp-$s)/60;
$m = $m_stamp%60; //分
$h_stamp=($m_stamp-$m)/60;
$h= $h_stamp%24;
$d = ($h_stamp-$h)/24;
echo "$d 天 $h 小时$m 分钟 $s 秒";
echo "<br>";