phpjs/functions/datetime/gmdate.js

php.js offers community built php functions in javascript

function gmdate(format, timestamp) {
  // From: http://phpjs.org/functions
  // +   original by: Brett Zamir (http://brett-zamir.me)
  // +   input by: Alex
  // +   bugfixed by: Brett Zamir (http://brett-zamir.me)
  // -    depends on: date
  // *     example 1: gmdate('H:m:s \\m \\i\\s \\m\\o\\n\\t\\h', 1062402400); // Return will depend on your timezone
  // *     returns 1: '07:09:40 m is month'
  var dt = typeof timestamp === 'undefined' ? new Date() : // Not provided
      typeof timestamp === 'object' ? new Date(timestamp) : // Javascript Date()
      new Date(timestamp * 1000); // UNIX timestamp (auto-convert to int)
  timestamp = Date.parse(dt.toUTCString().slice(0, -4)) / 1000;
  return this.date(format, timestamp);
}