Convert seconds to Hour:Minute:Second

You can use the gmdate() function:

echo gmdate("H:i:s", 685);

One hour is 3600sec, one minute is 60sec so why not:

<?php

$init = 685;
$hours = floor($init / 3600);
$minutes = floor(($init / 60) % 60);
$seconds = $init % 60;

echo "$hours:$minutes:$seconds";

?>

which produces:

$ php file.php
0:11:25

(I've not tested this much, so there might be errors with floor or so)

here you go

function format_time($t,$f=':') // t = seconds, f = separator 
{
  return sprintf("%02d%s%02d%s%02d", floor($t/3600), $f, ($t/60)%60, $f, $t%60);
}

echo format_time(685); // 00:11:25