let timeleft = 60;

let timerId; // task id

​

function setup() {

  noCanvas();

​

  var timer = select("#timer");

  timer.html(getFormattedTime(timeleft - counter));

  function timeIt() {

    counter++;

    timer.html(getFormattedTime(timeleft - counter));

    if(counter >= timeleft) {

      print("hi");

      clearInterval(timerId);

    }

  }

​

  timerId = setInterval(timeIt, 100);

}

​

function draw() {

  noLoop();

}

​

function getFormattedTime(seconds) {

  /*

  1 hour = 3600 sec

  1 min = 60 sec

  */

  let hour = 0;

  let min = 0;

  let sec = 0;

  // hour

  hour = floor(seconds / 3600);

  seconds %= 3600;

​

  // min

  min = floor(seconds / 60);

  seconds %= 60;

  // sec

  sec = seconds;

  let timeStr = hour + ":" + min + ":" + sec;

  return timeStr;

}