JS时间工具类

/**
* 时间对象的格式化
*/
Date.prototype.format = function(format)
{
/*
* format="yyyy-MM-dd hh:mm:ss";
*/
var o = {
"M+" : this.getMonth() + 1,
"d+" : this.getDate(),
"h+" : this.getHours(),
"m+" : this.getMinutes(),
"s+" : this.getSeconds(),
"q+" : Math.floor((this.getMonth() + 3) / 3),
"S" : this.getMilliseconds()
}

if (/(y+)/.test(format))
{
format = format.replace(RegExp.$1, (this.getFullYear() + "").substr(4 - RegExp.$1.length));
}

for (var k in o)
{
if (new RegExp("(" + k + ")").test(format))
{
format = format.replace(RegExp.$1, RegExp.$1.length == 1 ? o[k] : ("00" + o[k]).substr(("" + o[k]).length));
}
}
return format;
}
/**
 * 获取给定日期的最大天数
 * yyyy-MM-dd 
 */
Date.prototype.maxDay  = function(){
var curDate = new Date(this.getFullYear(),this.getMonth(),1);
var nextDate = new Date(this.getFullYear(),this.getMonth()+1,1);
var days = (nextDate.getTime()-curDate.getTime())/(24*3600*1000);
return days;
}