title: moment.js issue on firefox
body: <p>This code works fine on chrome but does not work on firefox or IE.
  Note that it works fine when I remove the "+00:00"</p>
  
  <pre><code>&lt;script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.11.0/moment.min.js"&gt;&lt;/script&gt;
  &lt;script&gt;
   var now = moment("Sun Jun 01 2016 05:00:00+00:00").format('ddd MMM DD YYYY HH:mm:ssZ');
   alert(now);
  &lt;/script&gt;
  </code></pre>