jquery时间倒计时

代码：

js:

function countDown(time, id) {  //time的格式yyyy/MM/dd hh:mm:ss
var day_elem = $(id).find('.day');
var hour_elem = $(id).find('.hour');
var minute_elem = $(id).find('.minute');
var second_elem = $(id).find('.second');
var end_time = new Date(time).getTime(), //月份是实际月份-1
sys_second = (end_time - new Date().getTime()) / 1000;
var timer = setInterval(function () {
if (sys_second > 1) {
sys_second -= 1;
var day = Math.floor((sys_second / 3600) / 24);
var hour = Math.floor((sys_second / 3600) % 24);
var minute = Math.floor((sys_second / 60) % 60);
var second = Math.floor(sys_second % 60);
day_elem && $(day_elem).text(day); //计算天
$(hour_elem).text(hour < 10 ? "0" + hour : hour); //计算小时
$(minute_elem).text(minute < 10 ? "0" + minute : minute); //计算分钟
$(second_elem).text(second < 10 ? "0" + second : second); //计算秒杀
} else {
clearInterval(timer);
}
}, 1000);
}

html:

<p id="colockbox">
<span class="day" id="day">00</span>

<span class="hour">00</span>:

<span  class="minute">24</span>:

<span class="second">24</span>
</p>