var oResult = document.getElementById('result');
var countdown = new CountDown({
  time: 2 * 24 * 60 * 60 * 1000,
  onChange(currentTime) {
    oResult.innerText = CountDown.format(currentTime, "DD 天 HH 时 mm 分 ss 秒");
  },
  onEnd() {
    oResult.innerText = '倒计时结束！';
  }
});

countdown.start();