PHP: Format Duration

format-duration.js

var duration = 3600;
duration = parseInt(Math.abs(duration));
duration =
  String('00' + parseInt(duration / 3600)).slice(-2) + ':' +
  String('00' + parseInt((duration / 60) % 60)).slice(-2) + ':' +
  String('00' + parseInt(duration % 60)).slice(-2);

format-duration.php

<?php
  // Set our duration in seconds
  $duration = 3600;
  $isNegative = $duration < 0;
  $duration = abs($duration);
  $duration =
    str_pad($duration / 3600, 2, '0', STR_PAD_LEFT) . ':' .
    str_pad(($duration / 60) % 60, 2, '0', STR_PAD_LEFT) . ':' .
    str_pad($duration % 60, 2, '0', STR_PAD_LEFT);
  $duration = ($isNegative ? '-' : '') . $duration;
  echo $duration;