JavaScript count down, add hours & minutes

Question

So, I have the below (seconds countdown) in good order. But! I am trying to add hours & minutes as apart of the count down as well. Ideally keeping the same structure, and just using pure JS. I would like the output to be:

There is X hours, X minutes, and X seconds remaining on this Sale!

var count=30;

    var counter=setInterval(timer, 1000); //1000 will  run it every 1 second

    function timer()
    {
      count=count-1;
      if (count <= 0)
      {
         clearInterval(counter);
         return;
      }

     document.getElementById("timer").innerHTML=count + " secs"; // watch for spelling
    }

If the solution has to be a rewrite with jQuery or another library; that's fine. Just not preferable. Cheers and Salutations for any help.

Answer 1

Something like this:

var count = 30;
var counter = setInterval(timer, 1000); //1000 will  run it every 1 second

function timer() {
    count = count - 1;
    if (count == -1) {
        clearInterval(counter);
        return;
    }

    var seconds = count % 60;
    var minutes = Math.floor(count / 60);
    var hours = Math.floor(minutes / 60);
    minutes %= 60;
    hours %= 60;

    document.getElementById("timer").innerHTML = hours + "hours " + minutes + "minutes and" + seconds + " seconds left on this Sale!"; // watch for spelling
}

Answer 2

var totalSeconds = 3723; // lets say we have 3723 seconds on the countdown
                         // that's 1 hour, 2 minutes and 3 seconds.

var hours   = Math.floor(totalSeconds / 3600 );
var minutes = Math.floor(totalSeconds % 3600 / 60);
var seconds = totalSeconds % 60;

var result = [hours, minutes, seconds].join(':');
console.log(result);
// 1:2:3

• hours is seconds divided by the number of seconds in hour (3600) rounded down
• minutes is the remainder of the above division, divided by the number of seconds in a minute (60), rounded down.
• seconds is the remainder of total seconds divided by seconds in a minute.

Each calculation after hour has to use a modulus calculation to get the remainder, because you don't care about total time at that step, just progress to the next tick.