代码：
<!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>javascript节日倒计时</title> <style type="text/css"> .keleyilcd { background-color: black; color: yellow; font: bold 18px MS Sans Serif; padding: 3px; } .keleyilcd sup { font-size: 80%; } #keleyi { font-family: "Lucida Grande", "Lucida Sans Unicode", Verdana, Arial, Helvetica, sans-serif; font-size: 19px; font-weight: bold; color: #164BA0; background-color: #D1D1D1; border: 1px solid #83AAD3; width: 400px; text-align: center; } #keleyi span { font-size: 80%; } </style> <script type="text/javascript"> function cdtime(container, targetdate) { if (!document.getElementById || !document.getElementById(container)) return this.container = document.getElementById(container) this.currentTime = new Date() this.targetdate = new Date(targetdate) this.timesup = false this.updateTime() } cdtime.prototype.updateTime = function () { var thisobj = this this.currentTime.setSeconds(this.currentTime.getSeconds() + 1) setTimeout(function () { thisobj.updateTime() }, 1000) //update time every second } cdtime.prototype.displaycountdown = function (baseunit, functionref) { this.baseunit = baseunit this.formatresults = functionref this.showresults() } cdtime.prototype.showresults = function () { var thisobj = this var timediff = (this.targetdate - this.currentTime) / 1000 if (timediff < 0) { //if time is up keleyi.com this.timesup = true this.container.innerHTML = this.formatresults() return } var oneMinute = 60 var oneHour = 60 * 60 var oneDay = 60 * 60 * 24 var dayfield = Math.floor(timediff / oneDay) var hourfield = Math.floor((timediff - dayfield * oneDay) / oneHour) var minutefield = Math.floor((timediff - dayfield * oneDay - hourfield * oneHour) / oneMinute) var secondfield = Math.floor((timediff - dayfield * oneDay - hourfield * oneHour - minutefield * oneMinute)) if (this.baseunit == "hours") { hourfield = dayfield * 24 + hourfield dayfield = "n/a" } else if (this.baseunit == "minutes") { minutefield = dayfield * 24 * 60 + hourfield * 60 + minutefield dayfield = hourfield = "n/a" } else if (this.baseunit == "seconds") { var secondfield = timediff dayfield = hourfield = minutefield = "n/a" } this.container.innerHTML = this.formatresults(dayfield, hourfield, minutefield, secondfield) setTimeout(function () { thisobj.showresults() }, 1000) //update results every second } function formatresults() { if (this.timesup == false) { var displaystring = arguments[0] + " days " + arguments[1] + " hours " + arguments[2] + " minutes " + arguments[3] + " seconds left" } else { var displaystring = "倒计时:" } return displaystring } function formatresults2() { if (this.timesup == false) { var displaystring = " 到2016新年还有<span class='kel"+"eyilcd'>" + arguments[0] + " <sup>天</sup> " + arguments[1] + " <sup>时</sup> " + arguments[2] + " <sup>分</sup> " + arguments[3] + " <sup>秒</sup></span>" } else { var displaystring = "" alert("Happy new year!");//到确定节日，提示! } return displaystring } </script> </head> <body> <div id="countdowncontainer"></div> <br /> <div id="countdowncontainer2"></div> <hr /> <div id="keleyi">Christmas Countdown</div> <script type="text/javascript"> var futuredate = new cdtime("countdowncontainer", "Feb 8, 2016 00:00:00"); futuredate.displaycountdown("days", formatresults) var currentyear=new Date().getFullYear() var thisnewyear=(new Date().getMonth()>=11 && new Date().getDate()>25)? currentyear+1 : currentyear var newyear=new cdtime("countdowncontainer2", "Feb 8, "+thisnewyear+" 0:0:00"); newyear.displaycountdown("days", formatresults2); </script> <!--类似的特效，下面的方法更容易实现--> <script type="text/javascript"> function iCounter() { var keleyi=(new Date().getMonth()>=11 && new Date().getDate()>25)? (new Date().getFullYear())+1 : new Date().getFullYear(); var cDateTime=new Date(); var tDateTime=new Date("December 25, "+keleyi+" 0:0:00"); //var tDateTime=new Date("June 11, "+keleyi+" 0:0:00"); var timeDiff=(tDateTime-cDateTime)/1000; //difference btw target date and current date, in seconds var oneMin=60; //1 minute in seconds var oneHour=60*60; //1 hour in seconds var oneDay=60*60*24; //1 day in seconds var totalDay=Math.floor(timeDiff/oneDay); var totalHour=Math.floor((timeDiff-totalDay*oneDay)/oneHour); var totalMin=Math.floor((timeDiff-totalDay*oneDay-totalHour*oneHour)/oneMin); var totalSec=Math.floor((timeDiff-totalDay*oneDay-totalHour*oneHour-totalMin*oneMin)); //Disply Christmas Countdown to Web Browser document.getElementById("kel" + "eyi").innerHTML = '距离圣诞节还有<br />' + totalDay + ' <span>天,</span> ' + totalHour + ' <span>时,</span> ' + totalMin + ' <span>分,</span> ' + totalSec + ' <span>秒,</span>'; setTimeout("iCounter()",1000); } iCounter(); </script> </body> </html>