Are you looking for a simple yet highly customisable Countdown Timer for your website? This might be what you are looking for.

Step 1 - Insert this HTML code to wherever you want the timer to run

HTML

<h1>Countdown Timer - Rename this Title</h1>
<div id="clockdiv">
  <div>
    <span class="days"></span>
    <div class="smalltext">Days</div>
  </div>
  <div>
    <span class="hours"></span>
    <div class="smalltext">Hours</div>
  </div>
  <div>
    <span class="minutes"></span>
    <div class="smalltext">Minutes</div>
  </div>
  <div>
    <span class="seconds"></span>
    <div class="smalltext">Seconds</div>
  </div>
</div>

Step 2 - Add this script to your Header or Footer "Code Injection" area

iQuery

<script>
function getTimeRemaining(endtime) {
  var t = Date.parse(endtime) - Date.parse(new Date());
  var seconds = Math.floor((t / 1000) % 60);
  var minutes = Math.floor((t / 1000 / 60) % 60);
  var hours = Math.floor((t / (1000 * 60 * 60)) % 24);
  var days = Math.floor(t / (1000 * 60 * 60 * 24));
  return {
    'total': t,
    'days': days,
    'hours': hours,
    'minutes': minutes,
    'seconds': seconds
  };
}

function initializeClock(id, endtime) {
  var clock = document.getElementById(id);
  var daysSpan = clock.querySelector('.days');
  var hoursSpan = clock.querySelector('.hours');
  var minutesSpan = clock.querySelector('.minutes');
  var secondsSpan = clock.querySelector('.seconds');

  function updateClock() {
    var t = getTimeRemaining(endtime);

    daysSpan.innerHTML = t.days;
    hoursSpan.innerHTML = ('0' + t.hours).slice(-2);
    minutesSpan.innerHTML = ('0' + t.minutes).slice(-2);
    secondsSpan.innerHTML = ('0' + t.seconds).slice(-2);

    if (t.total <= 0) {
      clearInterval(timeinterval);
    }
  }

  updateClock();
  var timeinterval = setInterval(updateClock, 1000);
}

var deadline = new Date(Date.parse(new Date('2020/10/10')) + 150 * 24 * 60 * 60 * 1000);
initializeClock('clockdiv', deadline);
</script>

Change the Date '2020/10/102' in the last line accordingly but keep the quotation marks.

Step 3 - Design your countdown timer to your own judgement. 

CSS

#clockdiv{
    color: #c42130;
    display: inline-block;
    font-weight: 100;
    text-align: center;
    font-size: 50px;
    padding-bottom:30px;
}

#clockdiv > div {
    padding: 10px;
    background: ;
    display: inline-block;
}

#clockdiv div > span{
    padding: 20px;
    border-radius: 100%;
    background: #ffff;
    display: inline-block;
}

.smalltext {
    padding-top: 5px;
    font-size: 16px;
    color:#000000;
}

That's it. Enjoy!