gistfile1.js

var fs = require("fs");
var TwoStep = require("two-step");
var jsdom = require("jsdom");

TwoStep(
	function() { fs.readFile("./cities.json", this.val()); },
	function(err, cities) {
		if(err) { throw err; }

		cities = JSON.parse(cities);

		var info = this.valArray();
		for(var city in cities) {
			getCityInfo(city, cities[city], info.val());
		}
	},
	function(err, info) {
		if(err) { throw err; }
		
		fs.writeFile("./timezone-info.json", JSON.stringify(info, null, "\t"), this.val());
	},
	function(err) { if(err) { throw err; } }
);

function getCityInfo(shortName, url, callback) {
	TwoStep(
		function() { jsdom.env(url, ['http://code.jquery.com/jquery-1.7.1.min.js'], this.val()); },
		function(err, window) {
			if(err) { return callback(error); }

			var $ = window.$;
			return callback(
				null,
				{
					"short-name": shortName,
					url: url,
					name: $(".biggest").text(),
					abbreviation: $("#cta").text(),
					latitude: $(".rpad:contains(Latitude) tr:eq(0) td:not(:first-child)").text(),
					longitude: $(".rpad:contains(Latitude) tr:eq(1) td:not(:first-child)").text(),
					offset: $(".lpad tr:contains(offset) td:not(:first-child)").text() ||
						$(".lpad tr:contains(Standard time zone) td:not(:first-child)").text()
				}
			);
		}
	);
}