这里是一个JavaScript中显示倒计时的方法，从10一秒一秒地往下减直到计时结束（即0），代码如下：

runCount(10);function runCount(t){ if(t>0){ document.getElementById(‘shownum').innerHTML = t; t–; setTimeout(function(){runCount(t);},1000); }else{ document.getElementById(‘shownum').innerHTML = ‘倒计时结束！'; }}

　　运行该js代码前，需要先添加一个id为shownum的div。

js实现动态倒计时功能 * a是从后台接收到的时间戳，需转换成毫秒单位

<div> 距明年还有: <span id='daya'></span>天 <span id='hoursa'></span>小时 <span id='minua'></span>分 <span id='secoa'></span>秒</div><script type="text/javascript">/**** copyright WE 2012.7* js实现动态倒计时功能* a是从后台接收到的时间戳，需转换成毫秒单位**/ var a=12345678; //以毫秒为单位 function fomtime() { a=a-1000; var b=new Date(); b.setTime(0); var c=new Date(); c.setTime(a); var day1=b.getDate(); //为方便调用，把天数、小时等单独定义 var hours1=b.getHours(); var minu1=b.getMinutes(); var seco1=b.getSeconds(); var day2=c.getDate(); var hours2=c.getHours(); var minu2=c.getMinutes(); var seco2=c.getSeconds(); var day=day2-day1; var hours=hours2-hours1; var minu=minu2-minu1; var seco=seco2-seco1; document.getElementById('daya').innerHTML=day; document.getElementById('hoursa').innerHTML=hours; document.getElementById('minua').innerHTML=minu; document.getElementById('secoa').innerHTML=seco; setTimeout("fomtime()",1000); } fomtime();</script>

按天倒计时

HTML代码1:

<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>

HTML代码2:

<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
精确到秒的javascript倒计时代码

HTML代码:

<form name="form1"> <div align="center" align="center"> <center>离2013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>

某某运动会，按时间提示不同的阶段

HTML代码:

<!--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>

按小时倒计时

HTML代码:

<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>

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>

以上所述就是本文的全部内容了，希望大家能够喜欢。