/**

 * 获取本周、本季度、本月、上月的开始日期、结束日期

 */

var now = new Date();                    //当前日期

var nowDayOfWeek = now.getDay();         //今天本周的第几天

var nowDay = now.getDate();              //当前日

var nowMonth = now.getMonth();           //当前月

var nowYear = now.getYear();             //当前年

nowYear += (nowYear < 2000) ? 1900 : 0;  //    

var lastMonthDate = new Date();  //上月日期

lastMonthDate.setDate(1);

lastMonthDate.setMonth(lastMonthDate.getMonth()-1);

var lastYear = lastMonthDate.getYear();

var lastMonth = lastMonthDate.getMonth();  

//格式化日期：yyyy-MM-dd

function formatDate(date) {

    var myyear = date.getFullYear();

    var mymonth = date.getMonth()+1;

    var myweekday = date.getDate();      

    if(mymonth < 10){

        mymonth = "0" + mymonth;

    }

    if(myweekday < 10){

        myweekday = "0" + myweekday;

    }

    return (myyear+"-"+mymonth + "-" + myweekday);

}      

//获得某月的天数

function getMonthDays(myMonth){

    var monthStartDate = new Date(nowYear, myMonth, 1);

    var monthEndDate = new Date(nowYear, myMonth + 1, 1);

    var   days   =   (monthEndDate   -   monthStartDate)/(1000   *   60   *   60   *   24);

    return   days;

}     

//获得本季度的开始月份

function getQuarterStartMonth(){

    var quarterStartMonth = 0;

    if(nowMonth<3){

       quarterStartMonth = 0;

    }

    if(2<nowMonth && nowMonth<6){

       quarterStartMonth = 3;

    }

    if(5<nowMonth && nowMonth<9){

       quarterStartMonth = 6;

    }

    if(nowMonth>8){

       quarterStartMonth = 9;

    }

    return quarterStartMonth;

}     

//获得本周的开始日期

function getWeekStartDate() {

    var weekStartDate = new Date(nowYear, nowMonth, nowDay - nowDayOfWeek);

    return formatDate(weekStartDate);

}      

//获得本周的结束日期

function getWeekEndDate() {

    var weekEndDate = new Date(nowYear, nowMonth, nowDay + (6 - nowDayOfWeek));

    return formatDate(weekEndDate);

}      

//获得本月的开始日期

function getMonthStartDate(){

    var monthStartDate = new Date(nowYear, nowMonth, 1);

    return formatDate(monthStartDate);

}     

//获得本月的结束日期

function getMonthEndDate(){

    var monthEndDate = new Date(nowYear, nowMonth, getMonthDays(nowMonth));

    return formatDate(monthEndDate);

}     

//获得上月开始时间

function getLastMonthStartDate(){

    var lastMonthStartDate = new Date(nowYear, lastMonth, 1);

    return formatDate(lastMonthStartDate);

}  

//获得上月结束时间

function getLastMonthEndDate(){

    var lastMonthEndDate = new Date(nowYear, lastMonth, getMonthDays(lastMonth));

    return formatDate(lastMonthEndDate);

}  

//获得本季度的开始日期

function getQuarterStartDate(){     

    var quarterStartDate = new Date(nowYear, getQuarterStartMonth(), 1);

    return formatDate(quarterStartDate);

}     

//或的本季度的结束日期

function getQuarterEndDate(){

    var quarterEndMonth = getQuarterStartMonth() + 2;

    var quarterStartDate = new Date(nowYear, quarterEndMonth, getMonthDays(quarterEndMonth));

    return formatDate(quarterStartDate);

}