title: node-cron with timezones
body: <p>i have a <a href="http://nodejs.org/" rel="noreferrer">node</a>(v0.7.3-pre) server with <a href="https://github.com/ncb000gt/node-cron" rel="noreferrer">node-cron</a>(0.3.2) and <a href="https://github.com/TooTallNate/node-time" rel="noreferrer">node-time</a>(0.8.2):</p>
  
  <pre><code>var cronJob = require('cron').CronJob;
  var cronJ = new cronJob({
   cronTime: "00 29 16 6 * *",
   onTick: function() {
    console.log("Tick");
   },
   start:true,
   timeZone: "America/Los_Angeles"
  });
  console.log(cronJ);
  </code></pre>
  
  <p>it runs, but the Cron is allways working with the server time(UTC), and the returned cron is:</p>
  
  <pre><code>{ _callbacks: [ [Function] ],
    onComplete: undefined,
    cronTime:
     { source: '00 29 16 6 * *',
       zone: undefined,
       second: { '0': true },
       minute: { '29': true },
       hour: { '16': true },
       dayOfWeek:
  ...
  </code></pre>
  
  <p>the <code>zone</code> is set as <code>undefined</code>, am i missing something?</p>