Moment JS, UTC to Local time

HTML

<script src="//cdnjs.cloudflare.com/ajax/libs/moment.js/2.5.1/moment.min.js"></script>
<table>
    <tr>
       <td>Start time: 
       <input type="text" title="start time" value="2015-09-30 00:00">
       </td>
       <td>
       End time:
       <input type="text" title="end time" value="2015-10-01 15:53">
       </td>        
       <td>
       Duration:
       <input type="text" title="duration">
       </td>        
       
    </tr>

JavaScript

$(document).ready(function() {
    var start_time = $('input[title="start time"]').val();
    var end_time = $('input[title="End time"]').val();
    var d1 = moment(start_time, "YYYY-MM-DD HH:mm");
    var d2 = moment(end_time, "YYYY-MM-DD HH:mm");
    var duration = d2.diff(d1, 'hours')+1;
    var input = $('input[title="duration"]').val();
    if(input == ''){
         $('#duration').val('duration');
 });