[Video] JavaScript Countdown Timer in Oxygen

The following screencast provides the steps to implement JavaScript Countdown Timer from w3schools in Oxygen.

JS code:

// Set the date we're counting down to
var countDownDate = new Date("Nov 23, 2018 00:00:00").getTime();

// Update the count down every 1 second
var x = setInterval(function() {

  // Get todays date and time
  var now = new Date().getTime();

  // Find the distance between now and the count down date
  var distance = countDownDate - now;

  // Time calculations for days, hours, minutes and seconds
  var days = Math.floor(distance / (1000 * 60 * 60 * 24));
  var hours = Math.floor((distance % (1000 * 60 * 60 * 24)) / (1000 * 60 * 60));
  var minutes = Math.floor((distance % (1000 * 60 * 60)) / (1000 * 60));
  var seconds = Math.floor((distance % (1000 * 60)) / 1000);

  // Display the result in the element with id="headline-63-11"
  document.getElementById("headline-63-11").innerHTML = days + "d " + hours + "h "
  + minutes + "m " + seconds + "s ";

  // If the count down is finished, write some text 
  if (distance < 0) {
    clearInterval(x);
    document.getElementById("headline-63-11").innerHTML = "EXPIRED";
  }
}, 1000);

Update on March 24, 2020: Setting the date and time to come from a custom field – https://wpdevdesign.com/countdown-timer-using-acf-in-oxygen/