title: Need to format time zone offset using moment js
body: <p>I have a datepicker on my page, when I select any date it produced a result something like</p>
  
  <pre><code>Sun Sep 07 2014 00:00:00 GMT+0500 (Pakistan Standard Time)
  </code></pre>
  
  <p>And I need to format it: <code>YYYY-MM-DDTHH:mm:ss Z</code></p>
  
  <p>So, for this I use moment syntax</p>
  
  <pre><code>var date='Sun Sep 07 2014 00:00:00 GMT+0500 (Pakistan Standard Time)';
  moment(date).format('YYYY-MM-DDTHH:mm:ss Z');
  </code></pre>
  
  <p>which produces an output</p>
  
  <pre><code>2014-09-07T00:00:00 +05:00
  </code></pre>
  
  <p>That's good, but my api expect standard timezone offset 'Z' instead of parsing into local current time zone (i.e +5:00) in my case.</p>
  
  <p>So, I want to produce this </p>
  
  <pre><code>2014-09-07T00:00:00Z
  </code></pre>
  
  <p>How is it possible?</p>