title: Calculate number of days from bootstrap daterangepicker
body: <p>I'm using bootstrap jquery daterangepicker. My intention is to find the number of days between 2 dates.
  In my HTML I'm using 2 input fields as below</p>
  
  <pre class="lang-html prettyprint-override"><code>&lt;div class="col-12 form-group has-feedback"&gt;
      &lt;label&gt;From &lt;span class="text-danger"&gt;*&lt;/span&gt;&lt;/label&gt;
      &lt;input type="text" class="form-control has-feedback-left" id="fromdate" 
          placeholder="MM/DD/YYYY" name="fromdate"&gt;
  &lt;/div&gt;
  &lt;div class="col-12 form-group has-feedback"&gt;
      &lt;label&gt;To &lt;span class="text-danger"&gt;*&lt;/span&gt;&lt;/label&gt;
      &lt;input type="text" class="form-control has-feedback-left" id="todate" 
          placeholder="MM/DD/YYYY" name="todate"&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>Now I need to auto populate the number of days when user select the from date and to date to the below input value</p>
  
  <pre class="lang-html prettyprint-override"><code>&lt;div class="col-12 form-group has-feedback"&gt;
      &lt;label&gt;Number of days &lt;span class="text-danger"&gt;*&lt;/span&gt;&lt;/label&gt;
      &lt;input type="text" class="form-control has-feedback-left" name="numberdays" 
          id="numberdays" disabled&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>I have been referring the bootstrap jquery daterangepicker forum and other internet sources for a solution but unfortunate. Appreciate if anyone could help.</p>