js日期操作

获取当前日期：

var myDate = new Date();
myDate.getYear();        //获取当前年份(2位)
myDate.getFullYear();    //获取完整的年份(4位,1970-????)
myDate.getMonth();       //获取当前月份(0-11,0代表1月)
myDate.getDate();        //获取当前日(1-31)
myDate.getDay();         //获取当前星期X(0-6,0代表星期天)
myDate.getTime();        //获取当前时间(从1970.1.1开始的毫秒数)
myDate.getHours();       //获取当前小时数(0-23)
myDate.getMinutes();     //获取当前分钟数(0-59)
myDate.getSeconds();     //获取当前秒数(0-59)
myDate.getMilliseconds();    //获取当前毫秒数(0-999)
myDate.toLocaleDateString();     //获取当前日期
var mytime=myDate.toLocaleTimeString();     //获取当前时间
myDate.toLocaleString( );        //获取日期与时间

操作函数：

Date.prototype.isLeapYear 判断闰年
Date.prototype.Format 日期格式化
Date.prototype.DateAdd 日期计算
Date.prototype.DateDiff 比较日期差
Date.prototype.toString 日期转字符串
Date.prototype.toArray 日期分割为数组
Date.prototype.DatePart 取日期的部分信息
Date.prototype.MaxDayOfDate 取日期所在月的最大天数
Date.prototype.WeekNumOfYear 判断日期所在年的第几周
StringToDate 字符串转日期型
IsValidDate 验证日期有效性
CheckDateTime 完整日期时间检查
daysBetween 日期天数差

js代码：

js代码：

//---------------------------------------------------
// 判断闰年
//---------------------------------------------------
Date.prototype.isLeapYear = function()
{
return (0==this.getYear()%4&&((this.getYear()%100!=0)||(this.getYear()%400==0)));
}

//---------------------------------------------------
// 日期格式化
// 格式 YYYY/yyyy/YY/yy 表示年份
// MM/M 月份
// W/w 星期
// dd/DD/d/D 日期
// hh/HH/h/H 时间
// mm/m 分钟
// ss/SS/s/S 秒
//---------------------------------------------------
Date.prototype.Format = function(formatStr)
{
var str = formatStr;
var Week = ['日','一','二','三','四','五','六'];

str=str.replace(/yyyy|YYYY/,this.getFullYear());
str=str.replace(/yy|YY/,(this.getYear() % 100)>9?(this.getYear() % 100).toString():'0' + (this.getYear() % 100));

str=str.replace(/MM/,this.getMonth()>9?this.getMonth().toString():'0' + this.getMonth());
str=str.replace(/M/g,this.getMonth());

str=str.replace(/w|W/g,Week[this.getDay()]);

str=str.replace(/dd|DD/,this.getDate()>9?this.getDate().toString():'0' + this.getDate());
str=str.replace(/d|D/g,this.getDate());

str=str.replace(/hh|HH/,this.getHours()>9?this.getHours().toString():'0' + this.getHours());
str=str.replace(/h|H/g,this.getHours());
str=str.replace(/mm/,this.getMinutes()>9?this.getMinutes().toString():'0' + this.getMinutes());
str=str.replace(/m/g,this.getMinutes());

str=str.replace(/ss|SS/,this.getSeconds()>9?this.getSeconds().toString():'0' + this.getSeconds());
str=str.replace(/s|S/g,this.getSeconds());

return str;
}

//+---------------------------------------------------
//| 求两个时间的天数差 日期格式为 YYYY-MM-dd
//+---------------------------------------------------
function daysBetween(DateOne,DateTwo)
{
var OneMonth = DateOne.substring(5,DateOne.lastIndexOf ('-'));
var OneDay = DateOne.substring(DateOne.length,DateOne.lastIndexOf ('-')+1);
var OneYear = DateOne.substring(0,DateOne.indexOf ('-'));

var TwoMonth = DateTwo.substring(5,DateTwo.lastIndexOf ('-'));
var TwoDay = DateTwo.substring(DateTwo.length,DateTwo.lastIndexOf ('-')+1);
var TwoYear = DateTwo.substring(0,DateTwo.indexOf ('-'));

var cha=((Date.parse(OneMonth+'/'+OneDay+'/'+OneYear)- Date.parse(TwoMonth+'/'+TwoDay+'/'+TwoYear))/86400000);
return Math.abs(cha);
}


//+---------------------------------------------------
//| 日期计算
//+--------------------------------------------------- 

Date.prototype.DateAdd =function(strInterval, Number) {
var dtStr = this;
var dtstp = Date.parse(dtStr);
var dt = new Date(dtStr);
switch (strInterval) {
case 's': return new Date(dtstp + (1000 * Number));
case 'n': return new Date(dtstp + (60000 * Number));
case 'h': return new Date(dtstp + (3600000 * Number));
case 'd': return new Date(dtstp + (86400000 * Number));
case 'w': return new Date(dtstp + ((86400000 * 7) * Number));
case 'q': return new Date(dt.getFullYear(), (dt.getMonth()) + Number * 3, dt.getDate(), dt.getHours(), dt.getMinutes(), dt.getSeconds());
case 'm': return new Date(dt.getFullYear(), (dt.getMonth()) + Number, dt.getDate(), dt.getHours(), dt.getMinutes(), dt.getSeconds());
case 'y': return new Date((dt.getFullYear() + Number), dt.getMonth(), dt.getDate(), dt.getHours(), dt.getMinutes(), dt.getSeconds());
}
}

//+---------------------------------------------------
//| 比较日期差 dtEnd 格式为日期型或者有效日期格式字符串
//+---------------------------------------------------
Date.prototype.DateDiff = function(strInterval, dtEnd) {
var dtStart = this;
if (typeof dtEnd == 'string' )//如果是字符串转换为日期型
{
dtEnd = StringToDate(dtEnd);
}
switch (strInterval) {
case 's' :return parseInt((dtEnd - dtStart) / 1000);
case 'n' :return parseInt((dtEnd - dtStart) / 60000);
case 'h' :return parseInt((dtEnd - dtStart) / 3600000);
case 'd' :return parseInt((dtEnd - dtStart) / 86400000);
case 'w' :return parseInt((dtEnd - dtStart) / (86400000 * 7));
case 'm' :return (dtEnd.getMonth()+1)+((dtEnd.getFullYear()-dtStart.getFullYear())*12) - (dtStart.getMonth()+1);
case 'y' :return dtEnd.getFullYear() - dtStart.getFullYear();
}
}

//+---------------------------------------------------
//| 日期输出字符串，重载了系统的toString方法
//+---------------------------------------------------
Date.prototype.toString = function(showWeek)
{
var myDate= this;
var str = myDate.toLocaleDateString();
if (showWeek)
{
var Week = ['日','一','二','三','四','五','六'];
str += ' 星期' + Week[myDate.getDay()];
}
return str;
}

//+---------------------------------------------------
//| 日期合法性验证
//| 格式为：YYYY-MM-DD或YYYY/MM/DD
//+---------------------------------------------------
function IsValidDate(DateStr)
{
var sDate=DateStr.replace(/(^s+|s+$)/g,''); //去两边空格;
if(sDate=='') return true;
//如果格式满足YYYY-(/)MM-(/)DD或YYYY-(/)M-(/)DD或YYYY-(/)M-(/)D或YYYY-(/)MM-(/)D就替换为''
//数据库中，合法日期可以是:YYYY-MM/DD(2003-3/21),数据库会自动转换为YYYY-MM-DD格式
var s = sDate.replace(/[d]{ 4,4 }[-/]{ 1 }[d]{ 1,2 }[-/]{ 1 }[d]{ 1,2 }/g,'');
if (s=='') //说明格式满足YYYY-MM-DD或YYYY-M-DD或YYYY-M-D或YYYY-MM-D
{
var t=new Date(sDate.replace(/-/g,'/'));
var ar = sDate.split(/[-/:]/);
if(ar[0] != t.getYear() || ar[1] != t.getMonth()+1 || ar[2] != t.getDate())
{
//alert('错误的日期格式！格式为：YYYY-MM-DD或YYYY/MM/DD。注意闰年。');
return false;
}
}
else
{
//alert('错误的日期格式！格式为：YYYY-MM-DD或YYYY/MM/DD。注意闰年。');
return false;
}
return true;
}

//+---------------------------------------------------
//| 日期时间检查
//| 格式为：YYYY-MM-DD HH:MM:SS
//+---------------------------------------------------
function CheckDateTime(str)
{
var reg = /^(d+)-(d{ 1,2 })-(d{ 1,2 }) (d{ 1,2 }):(d{ 1,2 }):(d{ 1,2 })$/;
var r = str.match(reg);
if(r==null)return false;
r[2]=r[2]-1;
var d= new Date(r[1],r[2],r[3],r[4],r[5],r[6]);
if(d.getFullYear()!=r[1])return false;
if(d.getMonth()!=r[2])return false;
if(d.getDate()!=r[3])return false;
if(d.getHours()!=r[4])return false;
if(d.getMinutes()!=r[5])return false;
if(d.getSeconds()!=r[6])return false;
return true;
}

//+---------------------------------------------------
//| 把日期分割成数组
//+---------------------------------------------------
Date.prototype.toArray = function()
{
var myDate = this;
var myArray = Array();
myArray[0] = myDate.getFullYear();
myArray[1] = myDate.getMonth();
myArray[2] = myDate.getDate();
myArray[3] = myDate.getHours();
myArray[4] = myDate.getMinutes();
myArray[5] = myDate.getSeconds();
return myArray;
}

//+---------------------------------------------------
//| 取得日期数据信息
//| 参数 interval 表示数据类型
//| y 年 m月 d日 w星期 ww周 h时 n分 s秒
//+---------------------------------------------------
Date.prototype.DatePart = function(interval)
{
var myDate = this;
var partStr='';
var Week = ['日','一','二','三','四','五','六'];
switch (interval)
{
case 'y' :partStr = myDate.getFullYear();break;
case 'm' :partStr = myDate.getMonth()+1;break;
case 'd' :partStr = myDate.getDate();break;
case 'w' :partStr = Week[myDate.getDay()];break;
case 'ww' :partStr = myDate.WeekNumOfYear();break;
case 'h' :partStr = myDate.getHours();break;
case 'n' :partStr = myDate.getMinutes();break;
case 's' :partStr = myDate.getSeconds();break;
}
return partStr;
}

//+---------------------------------------------------
//| 取得当前日期所在月的最大天数
//+---------------------------------------------------
Date.prototype.MaxDayOfDate = function()
{
var myDate = this;
var ary = myDate.toArray();
var date1 = (new Date(ary[0],ary[1]+1,1));
var date2 = date1.dateAdd(1,'m',1);
var result = dateDiff(date1.Format('yyyy-MM-dd'),date2.Format('yyyy-MM-dd'));
return result;
}

//+---------------------------------------------------
//| 取得当前日期所在周是一年中的第几周
//+---------------------------------------------------
Date.prototype.WeekNumOfYear = function()
{
var myDate = this;
var ary = myDate.toArray();
var year = ary[0];
var month = ary[1]+1;
var day = ary[2];
document.write('< script language=VBScript> ');
document.write('myDate = Datue(''+month+'-'+day+'-'+year+'') ');
document.write('result = DatePart('ww', myDate) ');
document.write(' ');
return result;
}

//+---------------------------------------------------
//| 字符串转成日期类型
//| 格式 MM/dd/YYYY MM-dd-YYYY YYYY/MM/dd YYYY-MM-dd
//+---------------------------------------------------
function StringToDate(DateStr)
{

var converted = Date.parse(DateStr);
var myDate = new Date(converted);
if (isNaN(myDate))
{
//var delimCahar = DateStr.indexOf('/')!=-1?'/':'-';
var arys= DateStr.split('-');
myDate = new Date(arys[0],--arys[1],arys[2]);
}
return myDate;
}

若要显示:当前日期加时间(如:2009-06-12 12:00)

function CurentTime()
{
var now = new Date();

var year = now.getFullYear(); //年
var month = now.getMonth() + 1; //月
var day = now.getDate(); //日

var hh = now.getHours(); //时
var mm = now.getMinutes(); //分

var clock = year + "-";

if(month < 10)
clock += "0";

clock += month + "-";

if(day < 10)
clock += "0";

clock += day + " ";

if(hh < 10)
clock += "0";

clock += hh + ":";
if (mm < 10) clock += '0';
clock += mm;
return(clock);
}

来源：http://www.cnblogs.com/carekee/articles/1678041.html