The "strtotime()" function is used to parse about any English textual datetime description into a Unix timestamp.

   strtotime(time,now)

In the above syntax the "time" is a mandatory field, which specifies the string to parse, "now" is the optional field is a timestamp used to calculate the returned value, if left current time will be taken.

<?php
    echo date('m/d/Y h:i:s', strtotime('next tuesday'));
?>

In the above example the strtotime() function is used to return the date of next tuesday.