摘要：
您可以看到，js的date类几乎没有方法，很少有人扩展这个类，所以我做了一个扩展供您参考。欢迎添加。
大家可以看到js的date类的方法很少，而很少有人去扩展这个类，所以我就做了个扩展，供大家参考，欢迎大家补充。
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml" ><head> <title>datetime</title></head><body>
<script language="javascript" type="text/javascript">
Date.prototype.add = function(milliseconds){
var m = this.getTime() + milliseconds; return new Date(m);
};Date.prototype.addSeconds = function(second){ return this.add(second * 1000);};Date.prototype.addMinutes = function(minute){ return this.addSeconds(minute*60);};Date.prototype.addHours = function(hour){ return this.addMinutes(60*hour);};Date.prototype.addDays = function(day){ return this.addHours(day * 24);};Date.isLeepYear = function(year){ return (year % 4 == 0 && year % 100 != 0)};Date.daysInMonth = function(year,month){ if(month == 2){ if(year % 4 == 0 && year % 100 != 0) return 29; else return 28; } else if((month <= 7 && month % 2 == 1) || (month > 7 && month % 2 == 0)) return 31; else return 30;};Date.prototype.addMonth = function(){ var m = this.getMonth(); if(m == 11)return new Date(this.getFullYear() + 1,1,this.getDate(),this.getHours(),this.getMinutes(),this.getSeconds()); var daysInNextMonth = Date.daysInMonth(this.getFullYear(),this.getMonth() + 1); var day = this.getDate(); if(day > daysInNextMonth){ day = daysInNextMonth; } return new Date(this.getFullYear(),this.getMonth() + 1,day,this.getHours(),this.getMinutes(),this.getSeconds()); };Date.prototype.subMonth = function(){ var m = this.getMonth(); if(m == 0)return new Date(this.getFullYear() -1,12,this.getDate(),this.getHours(),this.getMinutes(),this.getSeconds()); var day = this.getDate(); var daysInPreviousMonth = Date.daysInMonth(this.getFullYear(),this.getMonth()); if(day > daysInPreviousMonth){ day = daysInPreviousMonth; } return new Date(this.getFullYear(),this.getMonth() - 1,day,this.getHours(),this.getMinutes(),this.getSeconds());};Date.prototype.addMonths = function(addMonth){ var result = false; if(addMonth > 0){ while(addMonth > 0){ result = this.addMonth(); addMonth -- ; } }else if(addMonth < 0){ while(addMonth < 0){ result = this.subMonth(); addMonth ++ ; } }else{ result = this; } return result;};Date.prototype.addYears = function(year){ return new Date(this.getFullYear() + year,this.getMonth(),this.getDate(),this.getHours(),this.getMinutes(),this.getSeconds());};var d = new Date();alert('d.addYears(2) = ' + d.addYears(2).toLocaleString());alert('d.addMonths(2) = ' + d.addMonths(2).toLocaleString());alert('d.addMonths(-2) = ' + d.addMonths(-2).toLocaleString());alert('d.addDays(2) = ' + d.addDays(2).toLocaleString());alert('d.addHours(2) = ' + d.addHours(2).toLocaleString());alert('d.addMinutes(2) = ' + d.addMinutes(2).toLocaleString());
alert('d.addSeconds(2) = ' + d.addSeconds(2).toLocaleString());</script></body></html>希望这个东西可以对大家有点用处。