title: Updating time offset with moment().utcOffset()
body: <p>I'm facing some issue trying to use <code>moment.js</code> for dealing with time offsets.</p>
  
  <p>I collect in an hidden input the local user time offset:</p>
  
  <pre><code>&lt;script type="text/javascript"&gt;
    $(document).ready(function () { 
      $('input#timeoffset').val(moment().utcOffset()); 
    });
  &lt;/script&gt;
  </code></pre>
  
  <p>The offset gets correctly stored (in my case its value is -240). Later on the server side (which runs in utc time) I try to update some db stored utcDate doing something like:</p>
  
  <pre><code>var userDate = moment(utcDate).utcOffset(offset)
  </code></pre>
  
  <p>My issue is the following: 
  if I run my code as above described I get no effects:</p>
  
  <ul>
  <li><code>utcDate:  20151001 012421 +0000</code></li>
  <li><code>userDate: 20151001 012421 +0000</code></li>
  </ul>
  
  <p>If I flip the offset sign I get:</p>
  
  <ul>
  <li><code>utcDate:  20151001 012421 +0000</code></li>
  <li><code>userDate: 20151001 052421 +0400</code></li>
  </ul>
  
  <p>I'm clearly doing something wrong (even if my expectation was that the first version was correct), do you have any hint?</p>
  
  <p>On client-side I'm using moment.js v2.10.6 while on the server-side moment-timezone.js v0.4.0 and moment.js v2.10.6</p>