js获取日期

 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<6){

            quarterStartMonth = 3;

        }

        if(5<9){

            quarterStartMonth = 6;

        }

        if(nowMonth>8){

            quarterStartMonth = 9;

        }

        return quarterStartMonth;

    }

 

    //今天

    var getCurrentDate = new Date(nowYear, nowMonth, nowDay);

    var getCurrentDate  = formatDate(getCurrentDate)

 

    //昨天

    var getYesterdayDate = new Date(nowYear, nowMonth, nowDay - 1);

    var getYesterdayDate =  formatDate(getYesterdayDate);

 

    //获得本周的开始日期

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

    var getWeekStartDate =  formatDate(getWeekStartDate);

    //获得本周的结束日期

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

    var getWeekEndDate =  formatDate(getWeekEndDate);

 

 

    //获得上周的开始日期

    var getUpWeekStartDate = new Date(nowYear, nowMonth, nowDay - nowDayOfWeek -7);

    var getUpWeekStartDate =  formatDate(getUpWeekStartDate);

 

    //获得上周的结束日期

    var getUpWeekEndDate = new Date(nowYear, nowMonth, nowDay + (6 - nowDayOfWeek - 7));

    var getUpWeekEndDate =  formatDate(getUpWeekEndDate);

 

 

    //获得本月的开始日期

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

    var getMonthStartDate =  formatDate(getMonthStartDate);

 

    //获得本月的结束日期

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

    var getMonthEndDate =  formatDate(getMonthEndDate);

 

    //获得上月开始时间

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

    var getLastMonthStartDate = formatDate(getLastMonthStartDate);

 

    //获得上月结束时间

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

    var getLastMonthEndDate = formatDate(getLastMonthEndDate);