Date difference in Days in PHP

Date difference in Days in PHP. Input two days and returns difference in days.

<?php

$time1="2012-12-19";
$time2="2011-12-16";

echo dayDiff($time1,$time2);

function dayDiff($time1,$time2)
{
$d1=strtotime($time1);
$d2=strtotime($time2);


return round(abs($d1 - $d2) / 60,2)/(24*60);

}

?>