JavaScript实现多种倒计时与时间显示效果

<!DOCTYPE html>
<html>
<head>
  <title>获取时间</title>
  <script type="text/javascript">
  window.onload = function(){
    showTime();
  }

  function showTime(){
    var myDate = new Date();
    var year = myDate.getFullYear();
    var month = myDate.getMonth() + 1;
    var date = myDate.getDate();
    var dateArr = ["日","一",'二','三','四','五','六'];
    var day = myDate.getDay();
    var hours = myDate.getHours();
    var minutes = formatTime(myDate.getMinutes());
    var seconds = formatTime(myDate.getSeconds());

    var systemTime = document.getElementById("time");
    systemTime.innerHTML = " " + year + "年" + month +"月" + date + "日" + " 星期" + dateArr[day] + " " + hours + ":" + minutes + ":" + seconds;
    setTimeout("showTime()",500);
  }

  //格式化时间：分秒。
  function formatTime (i){
    if(i < 10){
      i = "0" + i;
    }
    return i;
  }

  </script>
</head>
<body>
  <div id ='time'></div>
</body>
</html>

<!DOCTYPE html>
<html>
<head>
  <title>获取时间</title>
  <script type="text/javascript">
    window.onload = function(){
      deadTime();
    }
    function deadTime(){
      var nowTime = new Date();
      var finalTime = new Date("2015-11-11");
      var lefttime = (finalTime.getTime() - nowTime.getTime())/(1000*24*60*60);
      var date = Math.ceil(lefttime);
      document.getElementById("time").innerHTML = date;
    }
  </script>
</head>
<body>
  <div >距离双十一还有：<span id ='time'></span>天</div>
</body>
</html>

<!DOCTYPE html>
<html>
<head>
<title>团购——限时抢</title>

</head>

<body>

<div class="time"> <span id="LeftTime"></span></div>
</div>
<script>
function FreshTime()
{
    var endtime=new Date("2015/11/11,12:20:12");//结束时间
    var nowtime = new Date();//当前时间
    var lefttime=parseInt((endtime.getTime()-nowtime.getTime())/1000); 
    d=parseInt(lefttime/3600/24);
    h=parseInt((lefttime/3600)%24);
    m=parseInt((lefttime/60)%60);
    s=parseInt(lefttime%60);

    document.getElementById("LeftTime").innerHTML="距离活动结束还剩" + d+"天"+h+"小时"+m+"分"+s+"秒";
    if(lefttime<=0){
        document.getElementById("LeftTime").innerHTML="团购已结束";
        clearInterval(sh);
    }
}
    FreshTime();
    var sh;
    sh=setInterval(FreshTime,1000);
</script>
</body>
</html>