Countdown Timer

by Roman

HTML

<p id="timer"></p>

JavaScript

let countDownValue = 1000 * 60; // 60 seconds
let countDownDate = new Date(Date.now() + countDownValue).getTime();

let timer = setInterval(function() {
  let now = new Date().getTime();

  let distance = countDownDate - now;

  let days = Math.floor(distance / (1000 * 60 * 60 * 24));
  let hours = Math.floor((distance % (1000 * 60 * 60 * 24)) / (1000 * 60 * 60));
  let minutes = Math.floor((distance % (1000 * 60 * 60)) / (1000 * 60));
  let seconds = Math.floor((distance % (1000 * 60)) / 1000);

  document.getElementById("timer").innerHTML = days + "d " + hours + "h "
  + minutes + "m " + seconds + "s ";

  if (distance < 0) {
    clearInterval(timer);
    document.getElementById("timer").innerHTML = "EXPIRED";
  }
}, 1000);