用JavaScript实现精准的天时分秒倒计时自定义时间戳

 countDown(endTimeStamp) {
    var nowTimeStamp = new Date().getTime()
    var time = {}
    if (endTimeStamp > nowTimeStamp) {
      var mss = endTimeStamp - nowTimeStamp;
      var days = parseInt(mss / (1000 * 60 * 60 * 24))
      var hours = parseInt((mss % (1000 * 60 * 60 * 24)) / (1000 * 60 * 60))
      var minutes = parseInt((mss % (1000 * 60 * 60)) / (1000 * 60))
      var seconds = parseInt((mss % (1000 * 60)) / 1000)
      time = {
        day: days < 10 ? "0" + days : days,
        hour: hours < 10 ? "0" + hours : hours,
        minute: minutes < 10 ? "0" + minutes : minutes,
        second: seconds < 10 ? "0" + seconds : seconds,
        mss: mss,
      }
    } else {
      time = {
        day: '00',
        hour: '00',
        minute: '00',
        second: '00',
        mss: '00',
      }
    }
    return time
  },

this.countDown(1593432000000)