<!DOCTYPE html>
<html>
<body>
<?php
echo(strtotime("now") . "<br>");
echo(strtotime("5 September 2016") . "<br>");
echo(strtotime("+5 hours") . "<br>");
echo(strtotime("+1 week") . "<br>");
echo(strtotime("+1 week 3 days 7 hours 5 seconds") . "<br>");
echo(strtotime("next Monday") . "<br>");
echo(strtotime("last Sunday"));
?>
</body>
</html>