例子,php计算日期差。
 
以下代码不需要按下按钮,选择了两个文本框的时间后会自动计算时间,自动计算时间的代码在//隐藏日历代码块里,主要代码为:
 
//下边这段代码用来计算两个日期相差的天数   
var sDate1 = document.all.dateCreatedStart.value;   
 var sDate2 = document.all.dateCreatedStop.value;    
      var   aDate,   oDate1,   oDate2,   iDays     
      aDate   =   sDate1.split("-")     
      oDate1   =   new   Date(aDate[1]   +   '-'   +   aDate[2]   +   '-'   +   aDate[0])     //转换为3-1-2009格式     
      aDate   =   sDate2.split("-")     
      oDate2   =   new   Date(aDate[1]   +   '-'   +   aDate[2]   +   '-'   +   aDate[0])     
      iDays   =   parseInt(Math.abs(oDate1   -   oDate2)   /   1000   /   60   /   60   /24)     //把相差的毫秒数转换为天数     
    document.all.dateChangDu.value = iDays;   
//上边这段代码块用来计算两个日期相差的天数  
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">   
<HTML>   
<HEAD>   
<TITLE> New Document </TITLE>   
<META NAME="Generator" CONTENT="EditPlus">   
<META NAME="Author" CONTENT="">   
<META NAME="Keywords" CONTENT="">   
<META NAME="Description" CONTENT="">
<script language="JavaScript" type="text/javascript" >  
String.prototype.toDate = function(x, p) {   
if(x == null) x = "-";   
if(p == null) p = "ymd";   
var a = this.split(x);   
var y = parseInt(a[p.indexOf("y")]);   
//remember to change this next century ;)   
if(y.toString().length <= 2) y += 2000;   
if(isNaN(y)) y = new Date().getFullYear();   
var m = parseInt(a[p.indexOf("m")]) - 1;   
var d = parseInt(a[p.indexOf("d")]);   
if(isNaN(d)) d = 1;   
return new Date(y, m, d);   
}  
Date.prototype.format = function(style) {   
var o = {   
    "M+" : this.getMonth() + 1, //month   
    "d+" : this.getDate(),      //day   
    "h+" : this.getHours(),     //hour   
    "m+" : this.getMinutes(),   //minute   
    "s+" : this.getSeconds(),   //second   
    "w+" : "天一二三四五六".charAt(this.getDay()),   //week   
    "q+" : Math.floor((this.getMonth() + 3) / 3), //quarter   
    "S" : this.getMilliseconds() //millisecond   
}   
if(/(y+)/.test(style)) {   
    style = style.replace(RegExp.$1,   
    (this.getFullYear() + "").substr(4 - RegExp.$1.length));   
}   
for(var k in o){   
    if(new RegExp("("+ k +")").test(style)){   
      style = style.replace(RegExp.$1,   
        RegExp.$1.length == 1 ? o[k] :   
        ("00" + o[k]).substr(("" + o[k]).length));   
    }   
}   
return style;   
};
function Calendar(beginYear, endYear, lang, dateFormatStyle) {   
this.beginYear = 1990;   
this.endYear = 2010;   
this.lang = 0;            //0(中文) | 1(英文)   
this.dateFormatStyle = "yyyy-MM-dd";   
  
if (beginYear != null && endYear != null){   
    this.beginYear = beginYear;   
    this.endYear = endYear;   
}   
if (lang != null){   
    this.lang = lang   
}   
  
if (dateFormatStyle != null){   
    this.dateFormatStyle = dateFormatStyle   
}   
  
this.dateControl = null;   
this.panel = this.getElementById("calendarPanel");   
this.form = null;   
  
this.date = new Date();   
this.year = this.date.getFullYear();   
this.month = this.date.getMonth(); 
  
this.colors = {   
"cur_word"      : "#FFFFFF", //当日<SPAN class=hilite1>日期</SPAN>文字颜色   
"cur_bg"        : "#00FF00", //当日<SPAN class=hilite1>日期</SPAN>单元格背影色   
"sun_word"      : "#FF0000", //星期天文字颜色   
"sat_word"      : "#0000FF", //星期六文字颜色   
"td_word_light" : "#333333", //单元格文字颜色   
"td_word_dark" : "#CCCCCC", //单元格文字暗色   
"td_bg_out"     : "#EFEFEF", //单元格背影色   
"td_bg_over"    : "#FFCC00", //单元格背影色   
"tr_word"       : "#FFFFFF", //日历头文字颜色   
"tr_bg"         : "#666666", //日历头背影色   
"input_border" : "#CCCCCC", //input控件的边框颜色   
"input_bg"      : "#EFEFEF"   //input控件的背影色   
}   
  
this.draw();   
this.bindYear();   
this.bindMonth();   
this.changeSelect();   
this.bindData();   
} 
  
Calendar.language = {   
"year"   : [[""], [""]],   
"months" : [["一月","二月","三月","四月","五月","六月","七月","八月","九月","十月","十一月","十二月"],   
        ["JAN","FEB","MAR","APR","MAY","JUN","JUL","AUG","SEP","OCT","NOV","DEC"]   
         ],   
"weeks" : [["日","一","二","三","四","五","六"],   
        ["SUN","MON","TUR","WED","THU","FRI","SAT"]   
         ],   
"clear" : [["清空"], ["CLS"]],   
"today" : [["今天"], ["TODAY"]],   
"close" : [["关闭"], ["CLOSE"]]   
}   
  
Calendar.prototype.draw = function() {   
calendar = this;   
  
var mvAry = [];   
mvAry[mvAry.length] = ' <form name="calendarForm" style="margin: 0px;">';   
mvAry[mvAry.length] = '    <table width="100%" border="0" cellpadding="0" cellspacing="1">';   
mvAry[mvAry.length] = '      <tr>';   
mvAry[mvAry.length] = '        <th align="left" width="1%"><input style="border: 1px solid ' + calendar.colors["input_border"] + ';background-color:' + calendar.colors["input_bg"] + ';width:16px;height:20px;" name="prevMonth" type="button" id="prevMonth" value="<" /></th>';   
mvAry[mvAry.length] = '        <th align="center" width="98%" nowrap="nowrap"><select name="calendarYear" id="calendarYear" style="font-size:12px;"></select><select name="calendarMonth" id="calendarMonth" style="font-size:12px;"></select></th>';   
mvAry[mvAry.length] = '        <th align="right" width="1%"><input style="border: 1px solid ' + calendar.colors["input_border"] + ';background-color:' + calendar.colors["input_bg"] + ';width:16px;height:20px;" name="nextMonth" type="button" id="nextMonth" value=">" /></th>';   
mvAry[mvAry.length] = '      </tr>';   
mvAry[mvAry.length] = '    </table>';   
mvAry[mvAry.length] = '    <table id="calendarTable" width="100%" style="border:0px solid #CCCCCC;background-color:#FFFFFF" border="0" cellpadding="3" cellspacing="1">';   
mvAry[mvAry.length] = '      <tr>';   
for(var i = 0; i < 7; i++) {   
    mvAry[mvAry.length] = '      <th style="font-weight:normal;background-color:' + calendar.colors["tr_bg"] + ';color:' + calendar.colors["tr_word"] + ';">' + Calendar.language["weeks"][this.lang][i] + '</th>';   
}   
mvAry[mvAry.length] = '      </tr>';   
for(var i = 0; i < 6;i++){   
    mvAry[mvAry.length] = '    <tr align="center">';   
    for(var j = 0; j < 7; j++) {   
      if (j == 0){   
        mvAry[mvAry.length] = ' <td style="cursor:default;color:' + calendar.colors["sun_word"] + ';"></td>';   
      } else if(j == 6) {   
        mvAry[mvAry.length] = ' <td style="cursor:default;color:' + calendar.colors["sat_word"] + ';"></td>';   
      } else {   
        mvAry[mvAry.length] = ' <td style="cursor:default;"></td>';   
      }   
    }   
    mvAry[mvAry.length] = '    </tr>';   
}   
mvAry[mvAry.length] = '      <tr style="background-color:' + calendar.colors["input_bg"] + ';">';   
mvAry[mvAry.length] = '        <th colspan="2"><input name="calendarClear" type="button" id="calendarClear" value="' + Calendar.language["clear"][this.lang] + '" style="border: 1px solid ' + calendar.colors["input_border"] + ';background-color:' + calendar.colors["input_bg"] + ';width:100%;height:20px;font-size:12px;"/></th>';   
mvAry[mvAry.length] = '        <th colspan="3"><input name="calendarToday" type="button" id="calendarToday" value="' + Calendar.language["today"][this.lang] + '" style="border: 1px solid ' + calendar.colors["input_border"] + ';background-color:' + calendar.colors["input_bg"] + ';width:100%;height:20px;font-size:12px;"/></th>';   
mvAry[mvAry.length] = '        <th colspan="2"><input name="calendarClose" type="button" id="calendarClose" value="' + Calendar.language["close"][this.lang] + '" style="border: 1px solid ' + calendar.colors["input_border"] + ';background-color:' + calendar.colors["input_bg"] + ';width:100%;height:20px;font-size:12px;"/></th>';   
mvAry[mvAry.length] = '      </tr>';   
mvAry[mvAry.length] = '    </table>';   
mvAry[mvAry.length] = ' </form>';   
this.panel.innerHTML = mvAry.join("");   
this.form = document.forms["calendarForm"];   
  
this.form.prevMonth.onclick = function () {calendar.goPrevMonth(this);}   
this.form.nextMonth.onclick = function () {calendar.goNextMonth(this);}   
  
this.form.calendarClear.onclick = function () {calendar.dateControl.value = "";calendar.hide();}   
this.form.calendarClose.onclick = function () {calendar.hide();}   
this.form.calendarYear.onchange = function () {calendar.update(this);}   
this.form.calendarMonth.onchange = function () {calendar.update(this);}   
this.form.calendarToday.onclick = function () {   
    var today = new Date();   
    calendar.date = today;   
    calendar.year = today.getFullYear();   
    calendar.month = today.getMonth();   
    calendar.changeSelect();   
    calendar.bindData();   
    calendar.dateControl.value = today.format(calendar.dateFormatStyle);   
    calendar.hide();   
}   
  
}   
  
//年份下拉框绑定数据   
Calendar.prototype.bindYear = function() {   
var cy = this.form.calendarYear;   
cy.length = 0;   
for (var i = this.beginYear; i <= this.endYear; i++){   
    cy.options[cy.length] = new Option(i + Calendar.language["year"][this.lang], i);   
}   
}   
  
//月份下拉框绑定数据   
Calendar.prototype.bindMonth = function() {   
var cm = this.form.calendarMonth;   
cm.length = 0;   
for (var i = 0; i < 12; i++){   
    cm.options[cm.length] = new Option(Calendar.language["months"][this.lang][i], i);   
}   
}   
  
//向前一月   
Calendar.prototype.goPrevMonth = function(e){   
if (this.year == this.beginYear && this.month == 0){return;}   
this.month--;   
if (this.month == -1) {   
    this.year--;   
    this.month = 11;   
}   
this.date = new Date(this.year, this.month, 1);   
this.changeSelect();   
this.bindData();   
}   
  
//向后一月   
Calendar.prototype.goNextMonth = function(e){   
if (this.year == this.endYear && this.month == 11){return;}   
this.month++;   
if (this.month == 12) {   
    this.year++;   
    this.month = 0;   
}   
this.date = new Date(this.year, this.month, 1);   
this.changeSelect();   
this.bindData();   
}   
  
//改变SELECT选中状态   
Calendar.prototype.changeSelect = function() {   
var cy = this.form.calendarYear;   
var cm = this.form.calendarMonth;   
for (var i= 0; i < cy.length; i++){   
    if (cy.options[i].value == this.date.getFullYear()){   
      cy[i].selected = true;   
      break;   
    }   
}   
for (var i= 0; i < cm.length; i++){   
    if (cm.options[i].value == this.date.getMonth()){   
      cm[i].selected = true;   
      break;   
    }   
}   
}   
  
//更新年、月   
Calendar.prototype.update = function (e){   
this.year = e.form.calendarYear.options[e.form.calendarYear.selectedIndex].value;   
this.month = e.form.calendarMonth.options[e.form.calendarMonth.selectedIndex].value;   
this.date = new Date(this.year, this.month, 1);   
this.changeSelect();   
this.bindData();   
}   
  
//绑定数据到月视图   
Calendar.prototype.bindData = function () {   
var calendar = this;   
var dateArray = this.getMonthViewArray(this.date.getYear(), this.date.getMonth());   
var tds = this.getElementById("calendarTable").getElementsByTagName_r("td");   
for(var i = 0; i < tds.length; i++) {   
//tds[i].style.color = calendar.colors["td_word_light"];   
tds[i].style.backgroundColor = calendar.colors["td_bg_out"];   
    tds[i].onclick = function () {return;}   
    tds[i].onmouseover = function () {return;}   
    tds[i].onmouseout = function () {return;}   
    if (i > dateArray.length - 1) break;   
    tds[i].innerHTML = dateArray[i];   
    if (dateArray[i] != " "){   
      tds[i].onclick = function () {   
        if (calendar.dateControl != null){   
          calendar.dateControl.value = new Date(calendar.date.getFullYear(),   
                                                calendar.date.getMonth(),   
                                                this.innerHTML).format(calendar.dateFormatStyle);   
        }   
        calendar.hide();   
      }   
      tds[i].onmouseover = function () {   
        this.style.backgroundColor = calendar.colors["td_bg_over"];   
      }   
      tds[i].onmouseout = function () {   
        this.style.backgroundColor = calendar.colors["td_bg_out"];   
      }   
      if (new Date().format(calendar.dateFormatStyle) ==   
          new Date(calendar.date.getFullYear(),   
                   calendar.date.getMonth(),   
                   dateArray[i]).format(calendar.dateFormatStyle)) {   
        //tds[i].style.color = calendar.colors["cur_word"];   
        tds[i].style.backgroundColor = calendar.colors["cur_bg"];   
        tds[i].onmouseover = function () {   
          this.style.backgroundColor = calendar.colors["td_bg_over"];   
        }   
        tds[i].onmouseout = function () {   
          this.style.backgroundColor = calendar.colors["cur_bg"];   
        }   
      }//end if   
    }   
}   
}   
  
//根据年、月得到月视图数据(数组形式)   
Calendar.prototype.getMonthViewArray = function (y, m) {   
var mvArray = [];   
var dayOfFirstDay = new Date(y, m, 1).getDay();   
var daysOfMonth = new Date(y, m + 1, 0).getDate();   
for (var i = 0; i < 42; i++) {   
    mvArray[i] = " ";   
}   
for (var i = 0; i < daysOfMonth; i++){   
    mvArray[i + dayOfFirstDay] = i + 1;   
}   
return mvArray;   
}   
  
//扩展 document.getElementByIdx_x(id) 多浏览器兼容性 from meizz tree source   
Calendar.prototype.getElementById = function(id){   
if (typeof(id) != "string" || id == "") return null;   
if (document.getElementByIdx_x) return document.getElementByIdx_x(id);   
if (document.all) return document.all(id);   
try {return eval_r(id);} catch(e){ return null;}   
}   
  
//扩展 object.getElementsByTagName_r(tagName)   
Calendar.prototype.getElementsByTagName = function(object, tagName){   
if (document.getElementsByTagName) return document.getElementsByTagName_r(tagName);   
if (document.all) return document.all.tags(tagName);   
}   
  
//取得HTML控件绝对位置   
Calendar.prototype.getAbsPoint = function (e){   
var x = e.offsetLeft;   
var y = e.offsetTop;   
while(e = e.offsetParent){   
    x += e.offsetLeft;   
    y += e.offsetTop;   
}   
return {"x": x, "y": y};   
}   
  
//显示日历   
Calendar.prototype.show = function (dateControl, popControl) {   
if (dateControl == null){   
    throw new Error("arguments[0] is necessary")   
}   
this.dateControl = dateControl;   
if (dateControl.value.length > 0){   
this.date = new Date(dateControl.value.toDate());   
this.year = this.date.getFullYear();   
this.month = this.date.getMonth();   
    this.changeSelect();   
    this.bindData();   
}   
if (popControl == null){   
    popControl = dateControl;   
}   
var xy = this.getAbsPoint(popControl);   
this.panel.style.left = xy.x + "px";   
this.panel.style.top = (xy.y + dateControl.offsetHeight) + "px";   
this.setDisplayStyle("select", "hidden");   
this.panel.style.visibility = "visible";   
}   
  
//隐藏日历   
Calendar.prototype.hide = function() {   
this.setDisplayStyle("select", "visible");   
this.panel.style.visibility = "hidden";   
  
//下边这段代码用来计算两个日期相差的天数   
var sDate1 = document.all.dateCreatedStart.value;   
 var sDate2 = document.all.dateCreatedStop.value;    
      var   aDate,   oDate1,   oDate2,   iDays     
      aDate   =   sDate1.split("-")     
      oDate1   =   new   Date(aDate[1]   +   '-'   +   aDate[2]   +   '-'   +   aDate[0])     //转换为3-1-2009格式     
      aDate   =   sDate2.split("-")     
      oDate2   =   new   Date(aDate[1]   +   '-'   +   aDate[2]   +   '-'   +   aDate[0])     
      iDays   =   parseInt(Math.abs(oDate1   -   oDate2)   /   1000   /   60   /   60   /24)     //把相差的毫秒数转换为天数     
    document.all.dateChangDu.value = iDays;   
//上边这段代码块用来计算两个日期相差的天数   
  
}   
  
//设置控件显示或隐藏   
Calendar.prototype.setDisplayStyle = function(tagName, style) {   
var tags = this.getElementsByTagName_r(null, tagName)   
for(var i = 0; i < tags.length; i++) {   
    if (tagName.toLowerCase() == "select" &&   
       (tags[i].name == "calendarYear" ||   
      tags[i].name == "calendarMonth")){   
      continue;   
    }   
    tags[i].style.visibility = style;   
}   
}   
  
document.write('<div id="calendarPanel" style="position: absolute;visibility: hidden;z-index: 9999;background-color: #FFFFFF;border: 1px solid #CCCCCC;width:175px;font-size:12px;"></div>');   
//var calendar = new Calendar();   
//调用calendar.show(dateControl, popControl);   
</script>   
<script language="JavaScript">   
// 计算两个日期的间隔天数   
function Computation(){   //sDate1和sDate2是2009-3-1格式     
var sDate1 = document.all.dateCreatedStart.value;   
 var sDate2 = document.all.dateCreatedStop.value;    
  var aDate, oDate1, oDate2, iDays     
  aDate = sDate1.split("-")     
  oDate1 = new Date(aDate[1] + '-' + aDate[2] + '-' + aDate[0])   //转换为3-1-2009格式     
  aDate = sDate2.split("-")     
  oDate2 = new Date(aDate[1] + '-' + aDate[2] + '-' + aDate[0])     
  iDays = parseInt(Math.abs(oDate1 - oDate2) / 1000 / 60 / 60 /24)   //把相差的毫秒数转换为天数     
  document.all.dateChangDu.value = iDays;   
}   
</script>   
</HEAD>   
  
<BODY onload="Computation()">   
时间开始:   
<input id="dateCreatedStart" style="ime-mode:disabled" onclick="new Calendar().show(this);" readonly="true" value="2009-3-1"/>   
  
<br/>   
时间终止:   
<input id="dateCreatedStop" style="ime-mode:disabled" onclick="new Calendar().show(this);" readonly="true" value="2009-3-15"/>
    <br>   
    时间长度:   
    <input id="dateChangDu"/>   
</BODY>   
</HTML>