效果如下

Time Until Christmas

1.这个特效是每天离 00：00：00的倒计时

CSS样式

<style>
html {
  height: 100%;
}
body {
  min-height: 100%;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  background: #EEE;
}
.flip-clock {
  text-align: center;
  perspective: 400px;
  margin: 20px auto;
}
.flip-clock *,
.flip-clock *:before,
.flip-clock *:after {
  box-sizing: border-box;
}
.flip-clock__piece {
  display: inline-block;
  margin: 0 5px;
}
.flip-clock__slot {
  font-size: 0.8vw;
}
.card {
  display: block;
  position: relative;
  padding-bottom: 0.72em;
  font-size: 10vw;
  line-height: 0.95;
}
.card__top,
.card__bottom,
.card__back::before,
.card__back::after {
  display: block;
  height: 0.72em;
  color: #ccc;
  background: #222;
  padding: 0.25em 0.25em;
  border-radius: 0.15em 0.15em 0 0;
  backface-visiblity: hidden;
  transform-style: preserve-3d;
  width: 1.8em;
}
.card__bottom {
  color: #FFF;
  position: absolute;
  top: 50%;
  left: 0;
  border-top: solid 1px #000;
  background: #393939;
  border-radius: 0 0 0.15em 0.15em;
  pointer-events: none;
  overflow: hidden;
}
.card__bottom::after {
  display: block;
  margin-top: -0.72em;
}
.card__back::before,
.card__bottom::after {
  content: attr(data-value);
}
.card__back {
  position: absolute;
  top: 0;
  height: 100%;
  left: 0%;
  pointer-events: none;
}
.card__back::before {
  position: relative;
  z-index: -1;
  overflow: hidden;
}
.flip .card__back::before {
  animation: flipTop 0.3s cubic-bezier(0.37, 0.01, 0.94, 0.35);
  animation-fill-mode: both;
  transform-origin: center bottom;
}
.flip .card__back .card__bottom {
  transform-origin: center top;
  animation-fill-mode: both;
  animation: flipBottom 0.6s cubic-bezier(0.15, 0.45, 0.28, 1);
}
@keyframes flipTop {
  0% {
    transform: rotateX(0deg);
    z-index: 2;
  }
  0%,
  99% {
    opacity: 1;
  }
  100% {
    transform: rotateX(-90deg);
    opacity: 0;
  }
}
@keyframes flipBottom {
  0%,
  50% {
    z-index: -1;
    transform: rotateX(90deg);
    opacity: 0;
  }
  51% {
    opacity: 1;
  }
  100% {
    opacity: 1;
    transform: rotateX(0deg);
    z-index: 5;
  }
}
</style>

HTML

<H1> Time Until Christmas </H1>
<div id='flip_timer'></div>

JavaScript

<script src="https://cdn.bootcss.com/jquery/3.3.1/jquery.min.js" type="text/javascript"></script>
<script>
console.clear();

function CountdownTracker(label, value){

  var el = document.createElement('span');

  el.className = 'flip-clock__piece';
  el.innerHTML = '<b class="flip-clock__card card"><b class="card__top"></b><b class="card__bottom"></b><b class="card__back"><b class="card__bottom"></b></b></b>' + 
    '<span class="flip-clock__slot">' + label + '</span>';

  this.el = el;

  var top = el.querySelector('.card__top'),
      bottom = el.querySelector('.card__bottom'),
      back = el.querySelector('.card__back'),
      backBottom = el.querySelector('.card__back .card__bottom');

  this.update = function(val){
    val = ( '0' + val ).slice(-2);
    if ( val !== this.currentValue ) {
      
      if ( this.currentValue >= 0 ) {
        back.setAttribute('data-value', this.currentValue);
        bottom.setAttribute('data-value', this.currentValue);
      }
      this.currentValue = val;
      top.innerText = this.currentValue;
      backBottom.setAttribute('data-value', this.currentValue);

      this.el.classList.remove('flip');
      void this.el.offsetWidth;
      this.el.classList.add('flip');
    }
  }
  
  this.update(value);
}

function getTimeRemaining(dateTime) {
var EndTime = new Date(dateTime);
// 当前系统时间
var NowTime = new Date();
//var t = EndTime.getTime() - NowTime.getTime();
  var t = Date.parse(EndTime) - Date.parse(NowTime);
  return {
    'Total': t,
    'Hours': Math.floor((t / (1000 * 60 * 60)) % 24),
    'Minutes': Math.floor((t / 1000 / 60) % 60),
    'Seconds': Math.floor((t / 1000) % 60)
  };
}

function Clock(countdown,callback) {
  countdown = countdown ? new Date(Date.parse(countdown)) : false;
  callback = callback || function(){};
  
  var updateFn = getTimeRemaining;
  

  this.el = document.createElement('div');
  this.el.className = 'flip-clock';

  var trackers = {},
      t = updateFn(countdown),
      key, timeinterval;
  for ( key in t ){
    if ( key === 'Total' ) { continue; }
    trackers[key] = new CountdownTracker(key, t[key]);
    this.el.appendChild(trackers[key].el);
  }

  var i = 0;
  function updateClock() {
    timeinterval = requestAnimationFrame(updateClock);
    
    // throttle so it's not constantly updating the time.
    if ( i++ % 10 ) { return; }
    
    var t = updateFn(countdown);
    if ( t.Total < 0 ) {
      cancelAnimationFrame(timeinterval);
      for ( key in trackers ){
        trackers[key].update( 0 );
      }
      callback();
      return;
    }

    for ( key in trackers ){
      trackers[key].update( t[key] );
    }
  }

  setTimeout(updateClock,500);
}

var day = new Date();
//console.log(day);
day.setTime(day.getTime()+24*60*60*1000);
day.setHours(00);
day.setMinutes(00);
day.setSeconds(00);
//var deadline = new Date(Date.parse(new Date()) + 12 * 24 * 60 * 60 * 1000);
//var deadline = new Date(Date.parse(new Date('2016/12/25')));
var c = new Clock(day, function(){ /* Do something when countdouwn is complete */ });
var page_timer = document.getElementById('flip_timer');
page_timer.appendChild(c.el);
</script>