JS获取当前日期时间及JS日期格式化

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

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：

//---------------------------------------------------
// 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 dtTmp = this;
switch (strInterval) {
case 's' :return new Date(Date.parse(dtTmp) + (1000 * Number));
case 'n' :return new Date(Date.parse(dtTmp) + (60000 * Number));
case 'h' :return new Date(Date.parse(dtTmp) + (3600000 * Number));
case 'd' :return new Date(Date.parse(dtTmp) + (86400000 * Number));
case 'w' :return new Date(Date.parse(dtTmp) + ((86400000 * 7) * Number));
case 'q' :return new Date(dtTmp.getFullYear(), (dtTmp.getMonth()) + Number*3, dtTmp.getDate(), dtTmp.getHours(), dtTmp.getMinutes(), dtTmp.getSeconds());
case 'm' :return new Date(dtTmp.getFullYear(), (dtTmp.getMonth()) + Number, dtTmp.getDate(), dtTmp.getHours(), dtTmp.getMinutes(), dtTmp.getSeconds());
case 'y' :return new Date((dtTmp.getFullYear() + Number), dtTmp.getMonth(), dtTmp.getDate(), dtTmp.getHours(), dtTmp.getMinutes(), dtTmp.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\> \n');
document.write('myDate = Datue(''+month+'-'+day+'-'+year+'') \n');
document.write('result = DatePart('ww', myDate) \n');
document.write(' \n');
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);
}

// 对Date的扩展，将 Date 转化为指定格式的String
// 月(M)、日(d)、小时(h)、分(m)、秒(s)、季度(q) 可以用 1-2 个占位符，
// 年(y)可以用 1-4 个占位符，毫秒(S)只能用 1 个占位符(是 1-3 位的数字)
// 例子：
// (new Date()).Format("yyyy-MM-dd hh:mm:ss.S") ==> 2006-07-02 08:09:04.423
// (new Date()).Format("yyyy-M-d h:m:s.S")      ==> 2006-7-2 8:9:4.18
Date.prototype.Format = function (fmt) { //author: meizz
var o = {
"M+": this.getMonth() + 1, //月份
"d+": this.getDate(), //日
"h+": this.getHours(), //小时
"m+": this.getMinutes(), //分
"s+": this.getSeconds(), //秒
"q+": Math.floor((this.getMonth() + 3) / 3), //季度
"S": this.getMilliseconds() //毫秒
};
if (/(y+)/.test(fmt)) fmt = fmt.replace(RegExp.$1, (this.getFullYear() + "").substr(4 - RegExp.$1.length));
for (var k in o)
if (new RegExp("(" + k + ")").test(fmt)) fmt = fmt.replace(RegExp.$1, (RegExp.$1.length == 1) ? (o[k]) : (("00" + o[k]).substr(("" + o[k]).length)));
return fmt;
}

调用：
var time1 = new Date().Format("yyyy-MM-dd");
var time2 = new Date().Format("yyyy-MM-dd HH:mm:ss");

<script language="javascript" type="text/javascript">
<!-- /** * 对Date的扩展，将 Date 转化为指定格式的String * 月(M)、日(d)、12小时(h)、24小时(H)、分(m)、秒(s)、周(E)、季度(q)
可以用 1-2 个占位符 * 年(y)可以用 1-4 个占位符，毫秒(S)只能用 1 个占位符(是 1-3 位的数字) * eg: * (new
Date()).pattern("yyyy-MM-dd hh:mm:ss.S")==> 2006-07-02 08:09:04.423
* (new Date()).pattern("yyyy-MM-dd E HH:mm:ss") ==> 2009-03-10 二 20:09:04
* (new Date()).pattern("yyyy-MM-dd EE hh:mm:ss") ==> 2009-03-10 周二 08:09:04
* (new Date()).pattern("yyyy-MM-dd EEE hh:mm:ss") ==> 2009-03-10 星期二 08:09:04
* (new Date()).pattern("yyyy-M-d h:m:s.S") ==> 2006-7-2 8:9:4.18
*/
Date.prototype.pattern=function(fmt) {
var o = {
"M+" : this.getMonth()+1, //月份
"d+" : this.getDate(), //日
"h+" : this.getHours()%12 == 0 ? 12 : this.getHours()%12, //小时
"H+" : this.getHours(), //小时
"m+" : this.getMinutes(), //分
"s+" : this.getSeconds(), //秒
"q+" : Math.floor((this.getMonth()+3)/3), //季度
"S" : this.getMilliseconds() //毫秒
};
var week = {
"0" : "/u65e5",
"1" : "/u4e00",
"2" : "/u4e8c",
"3" : "/u4e09",
"4" : "/u56db",
"5" : "/u4e94",
"6" : "/u516d"
};
if(/(y+)/.test(fmt)){
fmt=fmt.replace(RegExp.$1, (this.getFullYear()+"").substr(4 - RegExp.$1.length));
}
if(/(E+)/.test(fmt)){
fmt=fmt.replace(RegExp.$1, ((RegExp.$1.length>1) ? (RegExp.$1.length>2 ? "/u661f/u671f" : "/u5468") : "")+week[this.getDay()+""]);
}
for(var k in o){
if(new RegExp("("+ k +")").test(fmt)){
fmt = fmt.replace(RegExp.$1, (RegExp.$1.length==1) ? (o[k]) : (("00"+ o[k]).substr((""+ o[k]).length)));
}
}
return fmt;
}

var date = new Date();
window.alert(date.pattern("yyyy-MM-dd hh:mm:ss"));
// -->
</script>

Date.prototype.format = function (mask) {
var d = this;

var zeroize = function (value, length) {

if (!length) length = 2;

value = String(value);

for (var i = 0, zeros = ''; i < (length - value.length); i++) {

zeros += '0';

}

return zeros + value;

};

return mask.replace(/"[^"]*"|'[^']*'|/b ( ? : d {
1, 4
} | m {
1, 4
} | yy( ? : yy) ? | ([hHMstT]) / 1 ? | [lLZ]) / b / g, function ($0) {

switch ($0) {

case 'd':
return d.getDate();

case 'dd':
return zeroize(d.getDate());

case 'ddd':
return ['Sun', 'Mon', 'Tue', 'Wed', 'Thr', 'Fri', 'Sat'][d.getDay()];

case 'dddd':
return ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'][d.getDay()];

case 'M':
return d.getMonth() + 1;

case 'MM':
return zeroize(d.getMonth() + 1);

case 'MMM':
return ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'][d.getMonth()];

case 'MMMM':
return ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'][d.getMonth()];

case 'yy':
return String(d.getFullYear()).substr(2);

case 'yyyy':
return d.getFullYear();

case 'h':
return d.getHours() % 12 || 12;

case 'hh':
return zeroize(d.getHours() % 12 || 12);

case 'H':
return d.getHours();

case 'HH':
return zeroize(d.getHours());

case 'm':
return d.getMinutes();

case 'mm':
return zeroize(d.getMinutes());

case 's':
return d.getSeconds();

case 'ss':
return zeroize(d.getSeconds());

case 'l':
return zeroize(d.getMilliseconds(), 3);

case 'L':
var m = d.getMilliseconds();

if (m > 99) m = Math.round(m / 10);

return zeroize(m);

case 'tt':
return d.getHours() < 12 ? 'am' : 'pm';

case 'TT':
return d.getHours() < 12 ? 'AM' : 'PM';

case 'Z':
return d.toUTCString().match(/[A-Z]+$/);

// Return quoted strings with the surrounding quotes removed

default:
return $0.substr(1, $0.length - 2);

}

});

};