JSFiddle - React, Tailwind, and code Playground

HTML

<div id="countdown">
    <span id="row1"></span><br />
    <span id="row2"></span>
</div>

JavaScript

var end = new Date('October 08, 2012 00:55:00');

function toSt1(n) {
    var s = '';
    if (n < 10) s += '0';
    return (s + n).toString();
}

function toSt2(n) {
    var s = '';
    if (n < 10) s += '00';
    else if (n < 100) s += '0';
    return (s + n).toString();
}

var countdown = function() {
    var d = new Date();
    var count = Math.floor(end.getTime() - d.getTime());
    if (count > 0) {
        var miliseconds = toSt2(count % 1000);
        count = Math.floor(count / 1000);
        var seconds = toSt1(count % 60);
        count = Math.floor(count / 60);
        var minutes = toSt1(count % 60);
        count = Math.floor(count / 60);
        var hours = toSt1(count % 24);
        count = Math.floor(count / 24);
        var days = count;
        document.getElementById('row1').innerHTML = days + ' Days';
        document.getElementById('row2').innerHTML = hours + ' Hours ' + minutes + ' Minutes ' + seconds + ' Seconds ';
        setTimeout('countdown()', 100);
    } else {
        document.getElementById("countdown").innerHTML = "Time up";
    }
}
countdown();