JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://mindvelopers.com/jquery.countdown.min.js"></script>
<div id="clock"></div>

JavaScript

var data1 = new Date ('2015/02/16');
var data2 = new Date (data1);
var addHoras = 21;
data2.setHours ( data1.getHours() + addHoras);

$('#clock').countdown(data2, function(event) {
    $(this).html(event.strftime('%D dias %H:%M:%S'));
});