Calculating duration

[alexcg]

I've got both human-readable and unix timestamps of starttime and endtime of an event -- how would I calculate the duration in hours:minutes:seconds format?

Thanks!

[NogDog]

Untested:

$difference = $endUnixTime - $startUnixTime;
$hours = floor($difference / 3600);
$remainder = $difference % 3600;
$minutes = floor($remainder / 60);
$seconds = $remainder % 60;