日历控件，可运行在XHTML1.0下

JCalendar.js

//////////////////基本函数库/////////////////////////////
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//////////////JCalendar 类////////////////////////////
/***************************
 *JCalendar日历控件
 *@author brull
 *@email [email]brull@163.com[/email]
 *@date 2007-4-16
 *@更新 2007-5-27
 *@version 1.0 beta
 ***************************/
/*
 *@param year 年份,[可选]
 *@param month 月份，[可选]
 *@param date 日期，[可选]
 *或者是以横线间隔开的日期，比如：2007-4-27
 */
 
function JCalendar (year,month,date) {
 if($("calendar"))return;//唯一实例
 var _date = null;
 if(arguments.length == 3) _date = new Date(year,month-1,date);
 else if(arguments.length == 1 && typeof arguments[0] == "string")
  _date = eval("new Date(" + arguments[0].split("-").join() + ")");
 //如果没有参数，就初始化为当天日期
 else if(arguments.length == 0) _date = new Date();
 this.year = _date.getFullYear();
 this.month = _date.getMonth() + 1;
 this.date = _date.getDate();
 this.FIRSTYEAR = 1949;
 this.LASTYEAR = 2049;
 JCalendar.cur_year = this.year;
 JCalendar.cur_month = this.month;
 JCalendar.cur_date = this.date;
 JCalendar.cur_obj_id = null;//作为输入控件时保存当前文本框的id
}
/**
 *设置日历年份下拉菜单的年份范围
 *@first 第一个年份界限
 *@last 第二个年份界限
 *两个参数顺序可以颠倒
 */
JCalendar.prototype.setYears = function(first,last){
 if(isNaN(first) || isNaN(last)) return;
 this.FIRSTYEAR = Math.min(first,last);
 this.LASTYEAR = Math.max(first,last);
}
/**
 *以HTML串返回日历控件的HTML代码
 */
JCalendar.prototype.toString = function(){
 var fday = new Date(this.year,this.month-1,1).getDay();//每月第一天的星期数
 var select_year = new Array();//年份下拉菜单
 var select_month = new Array();//月份下拉菜单
 //日历里的每个单元格的数据，预先定义一段空数组，对应日历里第一周空的位置。[注意星期天对应的数是0]
 var date = new Array(fday > 0 ? fday - 1 : 0);
 var dayNum = new Date(this.year,this.month,0).getDate();//每月的天数
 var html_str = new Array();//保存日历控件的HTML代码
 var date_index = 0;//date数组的索引
 var weekDay = ["日","一","二","三","四","五","六"];
 
 //填充年份下拉菜单
 select_year.push("<select id='select_year'  style='display:none' onblur ="hide(this);show('title_year')" onchange='JCalendar.update(this.value,JCalendar.cur_month)'>");
 for(var i = this.FIRSTYEAR; i <= this.LASTYEAR; i++){
  if(i == this.year)
   select_year.push("<option value='" + i + "' selected='selected'>" + i +"</option>");
  else
   select_year.push("<option value='" + i + "'>" + i +"</option>");
 }
 select_year.push("</select>");
 
 //填充月份下拉菜单
 select_month.push("<select  id='select_month' style='display:none'  onblur ="hide(this);show('title_month')" onchange='JCalendar.update(JCalendar.cur_year,this.value)'>");
 for(var i = 1; i <= 12; i++){
  if(i == this.month)
   select_month.push("<option value='" + i + "' selected='selected'>" + i +"月</option>");
  else
   select_month.push("<option value='" + i + "'>" + i +"月</option>");
 }
 select_month.push("</select>");
 //初始化date数组
 for(var j = 1; j <= dayNum; j++){
  date.push(j);
 }
 //开始构建日历控件的HTML代码
 html_str.push("<table id='calendar'>");
 //日历表格caption
 html_str.push("<caption>" + "<a href='#'  id='prev_month' title='上一月份' onclick="JCalendar.update(JCalendar.cur_year,JCalendar.cur_month-1);return false;">«</a><a href='#' id='title_year' title='点击选择年份' onclick="hide(this);show('select_year');$('select_year').focus();return false">" + this.year + "年</a>" + select_year.join("") + "<a href='#' id='title_month' title='点击选择月份' onclick="hide(this);show('select_month');$('select_month').focus();return false">" + this.month + "月</a>" + select_month.join("") + "<a href='#' id='next_month' title='下一月份' onclick="JCalendar.update(JCalendar.cur_year,JCalendar.cur_month+1);return false;">»</a></caption>");
 //日历表格头
 html_str.push("<thead><tr>");
 for(var i = 0; i < 7; i++){//填充日历头
  html_str.push("<td>" + weekDay[i] + "</td>");
 }
 html_str.push("</tr></thead>");
 //日历主体
 var tmp;
 html_str.push("<tbody>");
 for(var i = 0; i < 6; i++){//填充日期，6行7列
  html_str.push("<tr>");
  for(var j = 0; j < 7; j++){
   tmp = date[date_index++];
   if(!tmp) tmp = "";
   html_str.push("<td ");
   if(tmp == this.date) html_str.push("id='c_today' ");
   html_str.push("onmouseover='JCalendar.over(this)' onmouseout='JCalendar.out(this)' onclick='JCalendar.click(this)'>" + tmp + "</td>");
  }
  html_str.push("</tr>");
 }
 html_str.push("</tbody></table>");
 return html_str.join("");
}
/**
 *特别显示关键天，典型例子博客的日历
 * 实现原理，为每个关键天的表格单元添加一个class,名字为keydate,CSS样式需要自己写，比如加个背景之类的
 *@param 日期的数组，比如：[1,4,6,9]
 */
JCalendar.prototype.setKeyDate = function(){
 var dates = arguments[0];
 var tds = $TN("td",$("calendar"));
 var reg = null;
 for(var i = 0; i < dates.length; i++){
  reg = new RegExp("\b" + dates[i] + "\b");
  for(var j = 7; j < tds.length; j++){//忽略表格头
   if(reg.test(tds[j].innerText)){
    tds[j].className = "keydate";
    break;
   }
  }
 }
}
/**
 *可以将日历控件邦定到某个文本框，在点击文本框的时候，会在direction指定的方向弹出日历,可以多次调用来帮定多个文本框
 *@ param obj_id 需要邦定日历的文本框的id
 *@ param direction 日历出现的相对于文本框的方向 [可选] 默认为right
 */
JCalendar.prototype.bind = function(obj_id,direction){
 var obj = $(obj_id);
 var direction = direction ? direction : "right";
 if(!obj)return;
 if(!$("calendar_container")){//唯一容器
  var contain = $DC("div");
  var s = contain.style;
  s.visibility = "hidden";
  s.position = "absolute";
  s.top = "0px";//不能占据页面空间
  s.zIndex = 65530;
  contain.id = "calendar_container";
  contain.innerHTML = this.toString();
  document.body.appendChild(contain);
  if(isIE){
   var ifm = $DC("iframe");
   var s = ifm.style;
   ifm.frameBorder = 0;
   ifm.height = (contain.clientHeight - 3) + "px";
   s.visibility = "inherit";
   s.filter = "alpha(opacity=0)";
   s.position = "absolute";
   s.top = "0px";//不能占据页面空间
   s.width = $("calendar_container").offsetWidth;
   s.zIndex = -1;
   contain.insertAdjacentElement("afterBegin",ifm);
  }
 }
 //覆盖日历事件
 JCalendar.onupdate = function () {};
 JCalendar.onclick = function (year,month,date){
  $(JCalendar.cur_obj_id).value = $(JCalendar.cur_obj_id).value.replace(/^[^s]*/i,year + '-' + month + '-' + date);
  hide("calendar_container");
 }
 //邦定事件
 document.attachEvent("onclick",function(){
  if($("calendar_container").style.visibility="visible")hide("calendar_container");
 });
 obj.attachEvent("onclick",function(e){
  var obj = e.srcElement;
  var dates =obj.value.split(/s/)[0].split("-");//文本框日期数组,文本框内容可能有时间这样的字串，即:2007-5-26 15:39
  var left = obj.offsetLeft , top = obj.offsetTop;
  var x,y,left,top;
  var contain = $("calendar_container");
  var body = isDTD ? document.documentElement : document.body;
  left = body.scrollLeft + e.clientX - e.offsetX;
  top = body.scrollTop + e.clientY - e.offsetY;
  switch(direction){
   case "right" : x = left + obj.offsetWidth; y = top;break;
   case "bottom" : x = left; y = top + obj.offsetHeight;break;
  }
  contain.style.top = y + "px";
  contain.style.left = x + "px";
  //更新日历日期
  if(dates.length == 3 && (JCalendar.cur_year != dates[0] || JCalendar.cur_month != dates[1] || JCalendar.cur_date != dates[2]))
   JCalendar.update(dates[0],dates[1],dates[2]);//如果文本框有时间则更新时间到文本框的时间
  else if (dates.length != 3){
   var now = new Date();
   JCalendar.update(now.getFullYear(),now.getMonth() + 1,now.getDate());
  }
  if($("calendar_container").style.visibility="hidden")show("calendar_container");
  e.cancelBubble = true;
  JCalendar.cur_obj_id = obj.id;
 });
 $("calendar_container").attachEvent("onclick",function(e){e.cancelBubble = true;});
}
/*===========================静态方法=======================================*/
/**
 *更新日历内容
 */
JCalendar.update = function(_year,_month,_date){
 date = new Date(_year,_month-1,1);
 var fday = date.getDay();//每月第一天的星期数
 var year = date.getFullYear();
 var month = date.getMonth() + 1;
 var dayNum = new Date(_year,_month,0).getDate();//每月的天数
 var tds = $TN("td",$("calendar"));
 var years = $("select_year").options;
 var months = $("select_month").options;
 var _date = _date ? _date : JCalendar.cur_date;
 //更新当前年月
 JCalendar.cur_year = year;
 JCalendar.cur_month = month;
 if(_date && _date <= dayNum) JCalendar.cur_date = _date;
 else if(_date > dayNum) JCalendar.cur_date = _date - dayNum;
 $("title_year").innerText = year + "年";
 $("title_month").innerText = month + "月";
 //更新年份下拉菜单选中项
 for(var i = years.length - 1; i >= 0; i-- ){
  if(years[i].value == year){
   $("select_year").selectedIndex = i;
   break;
  }
 }
 //更新月份下拉菜单选中项
 for(var i = months.length - 1; i >= 0; i-- ){
  if(months[i].value == month){
   $("select_month").selectedIndex = i;
   break;
  }
 }
 //清空日历内容,忽略日历头，即第一行
 for(var i = 7; i < tds.length; i++) tds[i].innerText = "";
 if( $("c_today"))$("c_today").removeAttribute("id");
 for(var j = 1; j <= dayNum; j++){
  tds[6 + fday + j].innerText = j;
  if(j == JCalendar.cur_date) tds[6 + fday + j].id = "c_today";
 }
 JCalendar.onupdate(year,month,JCalendar.cur_date);
}
JCalendar.click = function(obj){
 var tmp = $("c_today");
 if(tmp && tmp == obj){
  JCalendar.onclick(JCalendar.cur_year,JCalendar.cur_month,JCalendar.cur_date);
 }
 else if(obj.innerText != ""){
  if(tmp) tmp.removeAttribute("id");
  JCalendar.cur_date = parseInt(obj.innerText);
  obj.id = "c_today";
  JCalendar.onclick(JCalendar.cur_year,JCalendar.cur_month,JCalendar.cur_date);
 }
}
JCalendar.over = function(obj){
 if(obj.innerText != "") obj.className = "over";
}
JCalendar.out = function(obj){
 if(obj.innerText != "") obj.className = "";
}
//日历更改时执行的函数，可以更改为自己需要函数,控件传递过来的参数为当前日期
JCalendar.onupdate = function(year,month,date){
 alert("日历已更改，当前日历日期：" + year + "年" + month + "月" + date + "日");
}
//点击日期时执行的函数，可以更改为自己需要函数,控件传递过来的参数为当前日期
JCalendar.onclick = function(year,month,date){
 alert( "当前触发的日期：" + year + "年" + month + "月" + date + "日");
}
function showCalendar (obj) 
{
    var j = new JCalendar();
    j.setYears(1990, 2020);
    j.bind(obj, "bottom");
    //j.bind('b');
}

Calendar.css

/**********日历样式开始********************/
#calendar_container {
 width:160px;
 border:1px solid #06C;
}
#calendar {
 border-collapse:collapse;
 background-color:#FFF;
 width:160px;
 height:120px;
 margin:0px auto;
 cursor:default;
}
#calendar td {
 font-size:12px;
 text-align:center;
 vertical-align:middle;
 font-family:"宋体";
}
#calendar thead {
 background-color:#999;
 color:#FFF;
}
#calendar caption {
 background-color:#06C;
}
#calendar a{
 color:#F90;
 margin:0 5px;
 text-decoration:none;
}
#calendar #prev_month,#calendar #next_month {
 font-size:18px;
 margin:0;
}
#calendar #c_today {
 background-color:#036;
 color:#FFF;
}
#calendar .over {
 background-color:#CCC;
}
#calendar .keydate {
 color:#06F;
}

页面调用：

 <link href="calendar.css" type="text/css" rel="stylesheet" />
 <script language="javascript" src="JCalendar.js" type="text/javascript"> </script>
 <input type="text"  onclick='showCalendar(this)' />