JS date常用代码积累

Date.prototype.Format = function(fmt) {
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;
};

function getYestoday(date){
var yesterday_milliseconds=date.getTime()-1000*60*60*24;
var yesterday = new Date();
yesterday.setTime(yesterday_milliseconds);

var strYear = yesterday.getFullYear();
var strDay = yesterday.getDate();
var strMonth = yesterday.getMonth()+1;
if(strMonth<10)
{
strMonth="0"+strMonth;
}
datastr = strYear+"-"+strMonth+"-"+strDay;
return datastr;
}

//获得上个月在昨天这一天的日期
function getLastMonthYestdy(date){
var daysInMonth = new Array([0],[31],[28],[31],[30],[31],[30],[31],[31],[30],[31],[30],[31]);
var strYear = date.getFullYear();
var strDay = date.getDate();
var strMonth = date.getMonth()+1;
if(strYear%4 == 0 && strYear%100 != 0){
daysInMonth[2] = 29;
}
if(strMonth - 1 == 0)
{
strYear -= 1;
strMonth = 12;
}
else
{
strMonth -= 1;
}
strDay = daysInMonth[strMonth] >= strDay ? strDay : daysInMonth[strMonth];
if(strMonth<10)
{
strMonth="0"+strMonth;
}
if(strDay<10)
{
strDay="0"+strDay;
}
datastr = strYear+"-"+strMonth+"-"+strDay;
return datastr;
}

//获得上一年在昨天这一天的日期
function getLastYearYestdy(date){
var strYear = date.getFullYear() - 1;
var strDay = date.getDate();
var strMonth = date.getMonth()+1;
if(strMonth<10)
{
strMonth="0"+strMonth;
}
if(strDay<10)
{
strDay="0"+strDay;
}
datastr = strYear+"-"+strMonth+"-"+strDay;
return datastr;
}

var haomiao = +new Date();