JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://momentjs.com/downloads/moment.js"></script>
<div class="countdown"></div>
<div class="countdown1"></div>
<div class="countdown2"></div>

CSS

html, body {
 background-color:#ccc; 
}

JavaScript

var eventTime = '1366549200'; //Sun, 21 Apr 2013 13:00:00 GMT
    var currentTime = '1359032400'; //Thu, 24 Jan 2013 13:00:00 GMT

    var diffTime = eventTime - currentTime; //better to handle this in Controller to avoid timezone problem
    var duration = moment.duration(diffTime, 'seconds');
    var interval = 1;

    setInterval(function () {
        duration = moment.duration(duration.asSeconds() - interval, 'seconds');
        //.asSeconds()
        $('.countdown').text(Math.round(duration.asHours()) + 'h:' + Math.round(duration.asMinutes()) + 'm:' + Math.round(duration.asSeconds()) + 's');
        //.seconds()
        $('.countdown1').text(duration.days() + 'd:' + duration.hours() + 'h:' + duration.minutes() + 'm:' + duration.seconds() + 's');
        // .format()
        $('.countdown2').text(moment(duration).format('h[h]:mm[m]:ss[s]'));
    }, 1000);