How to display a CounterDown on a page?

Hello Forum !

What is the easiest way to display a counterdown on a SharePoint page?

I want something very simple and basic as I have a single fixed date for one single event. Therefore, Something like like the example below would be perfect:

You have:  22 Days, 23 Hours, 40 Seconds for ABC Event
 

Obviously, The timer must be accurate for all users so if someone from Europe or Australia or America opened the page, The timer must be correct.

I have tried using the script web part and reused some JavaScript code that I got from: (https://blog.smalldo.gs/2013/12/create-simple-countdown/) :


<h1 id="countdown-holder"></h1> 

<script src="/js/countdown.js"></script>

<script>
  var clock = document.getElementById("countdown-holder")
    , targetDate = new Date(2016, 00, 05); // June 1, 2016
 
  clock.innerHTML = countdown(targetDate).toString();
</script>

<script>
  var clock = document.getElementById("countdown-holder")
    , targetDate = new Date(2050, 00, 01); // Jan 1, 2050;
 
  clock.innerHTML = countdown(targetDate).toString();
  setInterval(function(){
    clock.innerHTML = countdown(targetDate).toString();
  }, 1000);
</script>



But, Nothing worked and nothing showed up on the page !!!


Could you please guide/correct me to be able to display it correctly ?