title: Moment.js - two dates difference in number of days
body: <p>I get incorrect results when trying to find numeric difference between two dates:</p>
  
  <pre><code>var startDate = moment( $('[name="date-start"]').val(), "DD.MM.YYYY"), // $('[name="date-start"]').val() === "13.04.2016"
  endDate       = moment( $('[name="date-end"]'  ).val(), "DD.MM.YYYY"); // $('[name="date-end"]').val() === "28.04.2016"
  
  var diff = startDate.diff(endDate);
  
  console.log( moment(diff).format('E') );
  </code></pre>
  
  <p>Between <code>13.04.2016</code> and <code>28.04.2016</code> I shouldn't get that difference is <strong>3</strong> or <strong>2</strong> days...</p>
  
  <p>I've tried to multiple combinations:</p>
  
  <ul>
  <li>swap <code>startDate.diff(endDate)</code> with <code>endDate.diff(startDate)</code></li>
  <li><code>format('E')</code> with something I've come up searching the SO</li>
  </ul>
  
  <p>result: all the time I get that difference is 3 or 2 days.</p>
  
  <p>What am I doing wrong? Thanks in advance.</p>