How to get time difference in minutes in PHP

print("<?php
$to_time=strtotime("2008-12-13 10:42:00");
$from_time=strtotime("2008-12-13 10:21:00");
echo round(abs($to_time - $from_time) / 60,2)." minute";
?>");

<?php
$date1 = time();
sleep(2000);
$date2 = time();
$mins = ($date2 - $date1) / 60;
echo $mins;
?>