微信小程序实现倒计时

<view class="title-item">倒计时</view>
<view class="countdown-item">
  <view class="countdown-title">
    <block>
      <text class='tui-conutdown-box'>{{days}}</text>
      <text class="countdown-text">天</text>
      <text class='tui-conutdown-box'>{{hours}}</text>
      <text class="countdown-text">时</text>
      <text class='tui-conutdown-box'>{{minutes}}</text>
      <text class="countdown-text">分</text>
      <text class='tui-conutdown-box'>{{seconds}}</text>
      <text class="countdown-text">秒</text>
    </block>
  </view>
</view>

.countdown-item {
  width: 100%;
  height: 100rpx;
  border: 0rpx solid red;
}

.countdown-title {
  width: 100%;
  height: 50rpx;
  line-height: 50rpx;
  font-size: 40rpx;
  color: #fff;
}

.tui-conutdown-box {
  display: inline-block;
  line-height: 50rpx;
  text-align: center;
  background-color: red;
  color: #fff;
  margin: 0 4rpx;
  padding: 10rpx 20rpx;
}

.tui-countdown-bg {
  background-color: #DF0101;
}

.countdown-text{
  color: #000;
}

Page({
    data: {
        nowDate: '2021-12-22 18:00:00', //结束时间
        countdown: '', //倒计时
        days: '00', //天
        hours: '00', //时
        minutes: '00', //分
        seconds: '00', //秒
    },
    
 countTime() {
    let days,hours, minutes, seconds;
    let nowDate = this.data.nowDate;
    console.log(nowDate)
    let that = this;
    let now = new Date().getTime();
    let end = new Date(nowDate).getTime(); //设置截止时间
    // console.log("开始时间："   now, "截止时间:"   end);
    let leftTime = end - now; //时间差                         
    if (leftTime >= 0) {
      days = Math.floor(leftTime / 1000 / 60 / 60 / 24);
      hours = Math.floor(leftTime / 1000 / 60 / 60 % 24);
      minutes = Math.floor(leftTime / 1000 / 60 % 60);
      seconds = Math.floor(leftTime / 1000 % 60);
      seconds = seconds < 10 ? "0"   seconds : seconds
      minutes = minutes < 10 ? "0"   minutes : minutes
      hours = hours < 10 ? "0"   hours : hours
      that.setData({
        countdown: days ":" hours   "："   minutes   "："   seconds,
        days,
        hours,
        minutes,
        seconds
      })
      // console.log(that.data.countdown)
      //递归每秒调用countTime方法，显示动态时间效果
      setTimeout(that.countTime, 1000);
    } else {
      that.setData({
        countdown: '已截止'
      })
    }
 },
 onLoad: function (options) {
    this.countTime();
 },
})