使用WallTime.js进行js时区转换，但得到一个错误

我有一个位于西海岸的客户端，但希望查看基于东海岸时间(美国/纽约)的信息。

我正在尝试使用WallTime库:https://github.com/sproutsocial/walltime-js

define(function(require) {
var _ = require('underscore'),
    Backbone = require('backbone'),
    WallTime = require('walltime');
require('backbone.relational');
require('walltime-data');

var DateRange = Backbone.RelationalModel.extend({
    initialize: function(opts) {
        var self = this,
            type = (opts && opts.type) || "today";
        if(type == "custom") {
            var undef = _.isUndefined(opts.start) && _.isUndefined(opts.end);
            if(undef)
                throw "'start' and/or 'end' date not present in options for type: custom";
        }
        function getNycDate(date){
            var someUTCDate = new Date(date.getTime()),
            nycWallTime = WallTime.UTCToWallTime(someUTCDate, "America/New_York");
            return nycWallTime;
        }
        function setup() {
            var now = getNycDate(new Date());
        }
     }
   }
}

当我试图计算墙时，我得到以下错误:未捕获的错误:在设置时区