Countdown function in pure js (no jquery)

countdown.js

// @author: Rawnly
// @version: 1.0.0 
// @url: https://rawnly.com

function countDown(id, date = "Jan 5 2018") {
  var int = setInterval(function() {
    // Get todays date and time
    var now = new Date().getTime();

    // Find the distance between now an the count down date
    var distance = date - 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="demo"
    document.getElementById(id).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(id).innerHTML = "00d 00h 00m 00s";
    }
  }, 1000);

  return int;
}


// EXAMPLE
// var c = countdown('myCountDown', "Jan 5, 2020");

// THAN IF YOU WANT TO CLEAR IT
// clearInterval(c);