JavaScript-时间倒计时

<script>var timer;countDown=function(){    timer=window.setInterval(function(){        ShowCountDown(2016,3,15);    }, 1000);     //clearInterval(timer);}function ShowCountDown(year,month,day) {     var now = new Date();     var endDate = new Date(year, month-1, day);     var leftTime=endDate.getTime()-now.getTime();     var leftsecond = parseInt(leftTime/1000);     var day1=Math.floor(leftsecond/(60*60*24));     var hour=Math.floor((leftsecond-day1*24*60*60)/3600);     var minute=Math.floor((leftsecond-day1*24*60*60-hour*3600)/60);     var second=Math.floor(leftsecond-day1*24*60*60-hour*3600-minute*60);     console.log(year+"年"+month+"月"+day+"日还有："+day1+"天"+hour+"小时"+minute+"分"+second+"秒"); } </script>

调用countDown()方法开始输出倒计时
调用clearInterval(timer)方法停止倒计时