A CodePen by Scott Grogan. CSS Chronograph - Experimenting with ways to visualize time via CSS

index.html

<div class="timer-group">
  <div class="timer hour">
    <div class="hand"><span></span></div>
    <div class="hand"><span></span></div>
  </div>
  <div class="timer minute">
    <div class="hand"><span></span></div>
    <div class="hand"><span></span></div>
  </div>
  <div class="timer second">
    <div class="hand"><span></span></div>
    <div class="hand"><span></span></div>
  </div>
  <div class="face">
    <h2>A CSS Chronograph</h2>
    <p id="lazy">00:00:00</p>  
  </div>
</div>

script.js

var defaults = {}
  , one_second = 1000
  , one_minute = one_second * 60
  , one_hour = one_minute * 60
  , one_day = one_hour * 24
  , startDate = new Date()
  , face = document.getElementById('lazy');

// http://paulirish.com/2011/requestanimationframe-for-smart-animating/
var requestAnimationFrame = (function() {
  return window.requestAnimationFrame       || 
         window.webkitRequestAnimationFrame || 
         window.mozRequestAnimationFrame    || 
         window.oRequestAnimationFrame      || 
         window.msRequestAnimationFrame     || 
         function( callback ){
           window.setTimeout(callback, 1000 / 60);
         };
}());

tick();

function tick() {

  var now = new Date()
    , elapsed = now - startDate
    , parts = [];

  parts[0] = '' + Math.floor( elapsed / one_hour );
  parts[1] = '' + Math.floor( (elapsed % one_hour) / one_minute );
  parts[2] = '' + Math.floor( ( (elapsed % one_hour) % one_minute ) / one_second );

  parts[0] = (parts[0].length == 1) ? '0' + parts[0] : parts[0];
  parts[1] = (parts[1].length == 1) ? '0' + parts[1] : parts[1];
  parts[2] = (parts[2].length == 1) ? '0' + parts[2] : parts[2];

  face.innerText = parts.join(':');
  
  requestAnimationFrame(tick);
  
}

style.css

* {
  box-sizing: border-box;
}

html {
  background: #111 url(http://codepen.io/images/classy_fabric.png);
  color: #fff;
  font-family: Arial, sans-serif;
}

body {
  padding: 20px;
}

.timer-group {
  height: 400px;
  margin: 0 auto;
  position: relative;
  width: 400px;
}

.timer {
  height: 100px;
  overflow: hidden;
  position: absolute;
  width: 100px;
}

.timer:after {
  background: #111 url(http://codepen.io/images/classy_fabric.png);
  border-radius: 50%;
  content: "";
  display: block;
  height: 80px;
  left: 10px;
  position: absolute;
  width: 80px;
  top: 10px;
}

.timer .hand {
  float: left;
  height: 100%;
  overflow: hidden;
  position: relative;
  width: 50%;
}

.timer .hand span {
  border: 50px solid rgba(0, 255, 255, .4);
  border-bottom-color: transparent;
  border-left-color: transparent;
  border-radius: 50%;
  display: block;
  height: 0;
  position: absolute;
  right: 0;
  top: 0;
  transform: rotate(225deg);
  width: 0;
}

.timer .hand:first-child {
  transform: rotate(180deg);
}

.timer .hand span {
  animation-duration: 4s;
  animation-iteration-count: infinite;
  animation-timing-function: linear;
}

.timer .hand:first-child span {
  animation-name: spin1;
}

.timer .hand:last-child span {
  animation-name: spin2; 
}

.timer.hour {
  height: 400px;
  left: 0;
  width: 400px;
  top: 0;
}

.timer.hour .hand span {
  animation-duration: 3600s; /*3600s;*/
  border-top-color: rgba(255, 0, 255, .4);
  border-right-color: rgba(255, 0, 255, .4);
  border-width: 200px;
}

.timer.hour:after {
  height: 360px;
  left: 20px;
  width: 360px;
  top: 20px;
}

.timer.minute {
  height: 350px;
  left: 25px;
  width: 350px;
  top: 25px;
}

.timer.minute .hand span {
  animation-duration: 60s;
  border-top-color: rgba(0, 255, 255, .4);
  border-right-color: rgba(0, 255, 255, .4);
  border-width: 175px;
}

.timer.minute:after {
  height: 310px;
  left: 20px;
  width: 310px;
  top: 20px;
}

.timer.second {
  height: 300px;
  left: 50px;
  width: 300px;
  top: 50px;
}

.timer.second .hand span {
  animation-duration: 10s;
  border-top-color: rgba(255, 255, 255, .4);
  border-right-color: rgba(255, 255, 255, .4);
  border-width: 150px;
}

.timer.second:after {
  height: 296px;
  left: 2px;
  width: 296px;
  top: 2px;
}

.face {
  height: 296px;
  left: 52px;
  padding: 200px 40px 0;
  position: absolute;
  width: 296px;
  text-align: center;
  top: 2px;
}

.face p {
  font-size: 40px;
  position: absolute;
  top: 100px;
  width: 200px;
  left: 50px;
}

@keyframes spin1 {
  0% {
    transform: rotate(225deg);
  }
  50% {
    transform: rotate(225deg);
  }
  100% {
    transform: rotate(405deg);
  }
}

@keyframes spin2 {
  0% {
    transform: rotate(225deg);
  }
  50% {
    transform: rotate(405deg);
  }
  100% {
    transform: rotate(405deg);
  }
}