phpjs/experimental/datetime/date_timezone_set.js

php.js offers community built php functions in javascript

function date_timezone_set(dt, tzo) {
  // http://kevin.vanzonneveld.net
  // +   original by: Brett Zamir (http://brett-zamir.me)
  // *     example 1: var dt = date_create();
  // *     example 1: var tzo = timezone_open();
  // *     example 1: date_timezone_set(dt, tzo);
  // *     returns 1: {}

  return dt.setTimezone(tzo);
}