PHP program to convert hours, minutes, and seconds into several seconds

<?php
//PHP program to convert hours, minutes, and seconds
//into several seconds.
$hh = 1;
$mm = 48;
$ss = 50;

$seconds = $hh * 3600 + $mm * 60 + $ss;

print ("Number of seconds: " . $seconds);
?>

Output
Number of seconds: 6530