jQuery addClass example

Change class name on click in jQuery

by John Doe

HTML

Only <span id='time'></span> left!

CSS

body {
  background: #20262E;
  padding: 20px;
  font-family: Helvetica;
}

#banner-message {
  background: #fff;
  border-radius: 4px;
  padding: 20px;
  font-size: 25px;
  text-align: center;
  transition: all 0.2s;
  margin: 0 auto;
  width: 300px;
}

button {
  background: #0084ff;
  border: none;
  border-radius: 5px;
  padding: 8px 14px;
  font-size: 15px;
  color: #fff;
}

#banner-message.alt {
  background: #0084ff;
  color: #fff;
  margin-top: 40px;
  width: 200px;
}

#banner-message.alt button {
  background: #fff;
  color: #000;
}

JavaScript

(function() {
  var start = new Date;
  start.setHours(23, 0, 0); // 11pm

  function pad(num) {
    return ("0" + parseInt(num)).substr(-2);
  }

  function tick() {
    var now = new Date;
    if (now > start) { // too late, go to tomorrow
      start.setDate(start.getDate() + 1);
    }
    var remain = ((start - now) / 1000);
    var hh = pad((remain / 60 / 60) % 60);
    var mm = pad((remain / 60) % 60);
    var ss = pad(remain % 60);
    document.getElementById('time').innerHTML =
      hh + ":" + mm + ":" + ss;
    setTimeout(tick, 1000);
  }

  document.addEventListener('DOMContentLoaded', tick);
})();