本文实例总结了js常用倒计时代码。分享给大家供大家参考，具体如下：
第一种：精确到秒的javascript倒计时代码
<form name="form1">
<div align="center" align="center">
<center>离2010年还有:<br>
<input type="textarea" name="left" size="35" style="text-align: center">
</center>
</div>
</form>
<script language="javascript">
startclock()
var timerid = null;
var timerrunning = false;
function showtime() {
today = new date();
var nowhour = today.gethours();
var nowminute = today.getminutes();
var nowmonth = today.getmonth();
var nowdate = today.getdate();
var nowyear = today.getyear();
var nowsecond = today.getseconds();
if (nowyear <2000)
nowyear=1900+nowyear;
today = null;
hourleft = 23 - nowhour
minuteleft = 59 - nowminute
secondleft = 59 - nowsecond
yearleft = 2009 - nowyear
monthleft = 12 - nowmonth - 1
dateleft = 31 - nowdate
if (secondleft<0)
{
secondleft=60+secondleft;
minuteleft=minuteleft-1;
}
if (minuteleft<0)
{
minuteleft=60+minuteleft;
hourleft=hourleft-1;
}
if (hourleft<0)
{
hourleft=24+hourleft;
dateleft=dateleft-1;
}
if (dateleft<0)
{
dateleft=31+dateleft;
monthleft=monthleft-1;
}
if (monthleft<0)
{
monthleft=12+monthleft;
yearleft=yearleft-1;
}
temp=yearleft+'年, '+monthleft+'月, '+dateleft+'天, '+hourleft+'小时, '+minuteleft+'分, '+secondleft+'秒'
document.form1.left.value=temp;
timerid = settimeout("showtime()",1000);
timerrunning = true;
}
var timerid = null;
var timerrunning = false;
function stopclock () {
if(timerrunning)
cleartimeout(timerid);
timerrunning = false;
}
function startclock () {
stopclock();
showtime();
}
// -->
</script>
第二种：某某运动会
<!--倒计时javascript begin-->
<script language="javascript">
<!--
function digitaltime1()
{
var deadline= new date("08/13/2007") //开幕倒计时
var symbol="8月13日"
var now = new date()
var diff = -480 - now.gettimezoneoffset() //是北京时间和当地时间的时间差
var leave = (deadline.gettime() - now.gettime()) + diff*60000
var day = math.floor(leave / (1000 * 60 * 60 * 24))
var hour = math.floor(leave / (1000*3600)) - (day * 24)
var minute = math.floor(leave / (1000*60)) - (day * 24 *60) - (hour * 60)
var second = math.floor(leave / (1000)) - (day * 24 *60*60) - (hour * 60 * 60) - (minute*60)
var deadline_2= new date("08/13/2004") //开幕后计时
var symbol_2="8月13日"
var now_2 = new date()
var diff_2 = -480 - now.gettimezoneoffset() //是北京时间和当地时间的时间差
var leave_2 = (now_2.gettime() - deadline_2.gettime()) + diff_2*60000
var day_2 = math.floor(leave_2 / (1000 * 60 * 60 * 24))
var hour_2 = math.floor(leave_2 / (1000*3600)) - (day_2 * 24)
var minute_2 = math.floor(leave_2 / (1000*60)) - (day_2 * 24 *60) - (hour_2 * 60)
var second_2 = math.floor(leave_2 / (1000)) - (day_2 * 24 *60*60) - (hour_2 * 60 * 60) - (minute_2*60)
day=day+1;
day_2=day_2+1;
if (day>0) //还未开幕
{
//liveclock1.innerhtml = "现在"+symbol+"天"
liveclock1.innerhtml = "<font
settimeout("digitaltime1()",1000)
}
if (day<0) //已经开幕
{
//liveclock1.innerhtml = "现在离"+symbol+"还有"+day+"天"+hour+"小时"+minute+"分"+second +"秒"
liveclock1.innerhtml = "<font
settimeout("digitaltime1()",1000)
}
if (day==0) //正在开幕
{
//liveclock1.innerhtml = "现在"+symbol+"天"
liveclock1.innerhtml = "<font
settimeout("digitaltime1()",1000)
}
if (day<0 & day_2>19) //某某运动会结束
{
//liveclock1.innerhtml = "现在离"+symbol+"还有"+day+"天"+hour+"小时"+minute+"分"+second +"秒"
liveclock1.innerhtml = "<font
settimeout("digitaltime1()",1000)
}
}
// -->
</script>
<!--倒计时javascript end-->
<body onload=digitaltime1()>
<div id= liveclock1></div>
</body>
第三种：小时倒计时
<script language="javascript">
<!--
var maxtime = 60*60 //一个小时，按秒计算，自己调整!
function countdown(){
if(maxtime>=0){
minutes = math.floor(maxtime/60);
seconds = math.floor(maxtime%60);
msg = "距离结束还有"+minutes+"分"+seconds+"秒";
document.all["timer"].innerhtml=msg;
if(maxtime == 5*60) alert('注意，还有5分钟!');
--maxtime;
}
else{
clearinterval(timer);
alert("时间到，结束!");
}
}
timer = setinterval("countdown()",1000);
//-->
</script>
<div id="timer" style="color:red"></div>
第四种：最简倒计时
<script language="javascript">
<!-- begin
var timedate= new date("january 14,2006");
var times="研究生考试";
var now = new date();
var date = timedate.gettime() - now.gettime();
var time = math.floor(date / (1000 * 60 * 60 * 24));
if (time >= 0) ;
document.write("<li><font color=#dedbde>现在离2006年"+times+"还有: <font color=#ffffff><b>"+time +"</b></font> 天</font></li>");
// end -->
</script>
第五种：最简倒计时二
<script language="javascript" type="text/javascript">
function djs(){
var urodz= new date("11/12/2008");
var now = new date();
var num
var ile = urodz.gettime() - now.gettime();
var dni = math.floor(ile / (1000 * 60 * 60 * 24));
if (dni >1)
num=dni+1
else if (dni == 1)num=2
else if (dni == 0)num=1
else num=0
document.write(num)
}
</script>
距某某开幕式还有 [<script language="javascript" type="text/javascript">djs()</script>] 天
第五个：javascript倒计时器 - 采用系统时间自校验
这次利用系统时间自校验倒计时, 无需手工调校使得倒计时更为精确, 代码及详细注释如下:
<span id="clock">00:01:11:00</span>
<input id="startb" type="button" value="start countdown!" onclick="run()">
<input id="endb" type="button" value="stop countdown!" onclick="stop()">
<br>
<input id="diff" type="text">
<input id="next" type="text">
<script language="javascript">
var normalelapse = 100;
var nextelapse = normalelapse;
var counter;
var starttime;
var start = clock.innertext;
var finish = "00:00:00:00";
var timer = null;
// 开始运行
function run() {
startb.disabled = true;
endb.disabled = false;
counter = 0;
// 初始化开始时间
starttime = new date().valueof();
// nextelapse是定时时间, 初始时为100毫秒
// 注意setinterval函数: 时间逝去nextelapse(毫秒)后, ontimer才开始执行
timer = window.setinterval("ontimer()", nextelapse);
}
// 停止运行
function stop() {
startb.disabled = false;
endb.disabled = true;
window.cleartimeout(timer);
}
window.onload = function() {
endb.disabled = true;
}
// 倒计时函数
function ontimer()
{
if (start == finish)
{
window.clearinterval(timer);
alert("time is up!");
return;
}
var hms = new string(start).split(":");
var ms = new number(hms[3]);
var s = new number(hms[2]);
var m = new number(hms[1]);
var h = new number(hms[0]);
ms -= 10;
if (ms < 0)
{
ms = 90;
s -= 1;
if (s < 0)
{
s = 59;
m -= 1;
}
if (m < 0)
{
m = 59;
h -= 1;
}
}
var ms = ms < 10 ? ("0" + ms) : ms;
var ss = s < 10 ? ("0" + s) : s;
var sm = m < 10 ? ("0" + m) : m;
var sh = h < 10 ? ("0" + h) : h;
start = sh + ":" + sm + ":" + ss + ":" + ms;
clock.innertext = start;
// 清除上一次的定时器
window.clearinterval(timer);
// 自校验系统时间得到时间差, 并由此得到下次所启动的新定时器的时间nextelapse
counter++;
var countersecs = counter * 100;
var elapsesecs = new date().valueof() - starttime;
var diffsecs = countersecs - elapsesecs;
nextelapse = normalelapse + diffsecs;
diff.value = countersecs + "-" + elapsesecs + "=" + diffsecs;
next.value = "nextelapse = " + nextelapse;
if (nextelapse < 0) nextelapse = 0;
// 启动新的定时器
timer = window.setinterval("ontimer()", nextelapse);
}
</script>
ps：这里再为大家推荐几款时间及计时器相关工具供大家参考使用：
在线秒表工具：
unix时间戳(timestamp)转换工具：
在线世界各地时间查询：
更多关于javascript相关内容感兴趣的读者可查看本站专题：《javascript时间与日期操作技巧总结》《javascript错误与调试技巧总结》、《javascript数据结构与算法技巧总结》、《javascript遍历算法与技巧总结》及《javascript数学运算用法总结》
希望本文所述对大家javascript程序设计有所帮助。