phpjs/experimental/datetime/timezone_name_get.js

php.js offers community built php functions in javascript

function timezone_name_get(tzo) {
  // http://kevin.vanzonneveld.net
  // +   original by: Brett Zamir (http://brett-zamir.me)
  // *     example 1: var tzo = timezone_open('Europe/Prague');
  // *     example 1: timezone_name_get(tzo);
  // *     returns 1: 'Europe/Prague'

  return tzo.getName();
}