Pomodoro algorythm

pomodoro-1.js

var session = 25 * 60 * 1000; // pomodoro session
var start = Number(new Date()); // set start time
var finish = start + session; // set finish time

function countdown () {
  var now = Number(new Date());
  var isFinished = (finish - now) > finish;
  if (!isFinished) {
    // check after 1 second
    setTimeout(countdown, 1000);
  } else {
    // finished
    alert('Done');
  }
};

countDown();