JS-时间函数

/**
* 日期范围工具类
*/
var daterangeutil = (function () {
    /***
    * 获得当前时间
    */
    this.getcurrentdate = function () {
        return new date();
    };

    /***
    * 获得本周起止时间
    */
    this. 

    /***
    * 获得本月的起止时间
    */
    this.getcurrentmonth = function () {
        //起止日期数组  
        var startstop = new array();
        //获取当前时间  
        var currentdate = this.getcurrentdate();
        //获得当前月份0-11  
        var currentmonth = currentdate.getmonth();
        //获得当前年份4位年  
        var currentyear = currentdate.getfullyear();
        //求出本月第一天  
        var firstday = new date(currentyear, currentmonth, 1);


        //当为12月的时候年份需要加1  
        //月份需要更新为0 也就是下一年的第一个月  
        if (currentmonth == 11) {
            currentyear++;
            currentmonth = 0; //就为  
        } else {
            //否则只是月份增加,以便求的下一月的第一天  
            currentmonth++;
        }


        //一天的毫秒数  
        var millisecond = 1000 * 60 * 60 * 24;
        //下月的第一天  
        var nextmonthdayone = new date(currentyear, currentmonth, 1);
        //求出上月的最后一天  
        var lastday = new date(nextmonthdayone.gettime() - millisecond);

        //添加至数组中返回  
        startstop.push(firstday);
        startstop.push(lastday);
        //返回  
        return startstop;
    };

    /**
    * 得到本季度开始的月份
    * @param month 需要计算的月份
    ***/
    this.getquarterseasonstartmonth = function (month) {
        var quartermonthstart = 0;
        var spring = 0; //春  
        var summer = 3; //夏  
        var fall = 6;   //秋  
        var winter = 9; //冬  
        //月份从0-11  
        if (month lt; 3) {
            return spring;
        }

        if (month lt; 6) {
            return summer;
        }

        if (month lt; 9) {
            return fall;
        }

        return winter;
    };

    /**
    * 获得该月的天数
    * @param year年份
    * @param month月份
    * */
    this.getmonthdays = function (year, month) {
        //本月第一天 1-31  
        var relativedate = new date(year, month, 1);
        //获得当前月份0-11  
        var relativemonth = relativedate.getmonth();
        //获得当前年份4位年  
        var relativeyear = relativedate.getfullyear();

        //当为12月的时候年份需要加1  
        //月份需要更新为0 也就是下一年的第一个月  
        if (relativemonth == 11) {
            relativeyear++;
            relativemonth = 0;
        } else {
            //否则只是月份增加,以便求的下一月的第一天  
            relativemonth++;
        }
        //一天的毫秒数  
        var millisecond = 1000 * 60 * 60 * 24;
        //下月的第一天  
        var nextmonthdayone = new date(relativeyear, relativemonth, 1);
        //返回得到上月的最后一天,也就是本月总天数  
        return new date(nextmonthdayone.gettime() - millisecond).getdate();
    };

    /**
    * 获得本季度的起止日期
    */
    this.getcurrentseason = function () {
        //起止日期数组  
        var startstop = new array();
        //获取当前时间  
        var currentdate = this.getcurrentdate();
        //获得当前月份0-11  
        var currentmonth = currentdate.getmonth();
        //获得当前年份4位年  
        var currentyear = currentdate.getfullyear();
        //获得本季度开始月份  
        var quarterseasonstartmonth = this.getquarterseasonstartmonth(currentmonth);
        //获得本季度结束月份  
        var quarterseasonendmonth = quarterseasonstartmonth + 2;

        //获得本季度开始的日期  
        var quarterseasonstartdate = new date(currentyear, quarterseasonstartmonth, 1);
        //获得本季度结束的日期  
        var quarterseasonenddate = new date(currentyear, quarterseasonendmonth, this.getmonthdays(currentyear, quarterseasonendmonth));
        //加入数组返回  
        startstop.push(quarterseasonstartdate);
        startstop.push(quarterseasonenddate);
        //返回  
        return startstop;
    };

    /***
    * 得到本年的起止日期
    * 
    */
    this.getcurrentyear = function () {
        //起止日期数组  
        var startstop = new array();
        //获取当前时间  
        var currentdate = this.getcurrentdate();
        //获得当前年份4位年  
        var currentyear = currentdate.getfullyear();

        //本年第一天  
        var currentyearfirstdate = new date(currentyear, 0, 1);
        //本年最后一天  
        var currentyearlastdate = new date(currentyear, 11, 31);
        //添加至数组  
        startstop.push(currentyearfirstdate);
        startstop.push(currentyearlastdate);
        //返回  
        return startstop;
    };

    /**
    * 返回上一个月的第一天date类型
    * @param year 年
    * @param month 月
    **/
    this.getpriormonthfirstday = function (year, month) {
        //年份为0代表,是本年的第一月,所以不能减  
        if (month == 0) {
            month = 11; //月份为上年的最后月份  
            year--; //年份减1  
            return new date(year, month, 1);
        }
        //否则,只减去月份  
        month--;
        return new date(year, month, 1);;
    };

    /**
    * 获得上一月的起止日期
    * ***/
    this.getpreviousmonth = function () {
        //起止日期数组  
        var startstop = new array();
        //获取当前时间  
        var currentdate = this.getcurrentdate();
        //获得当前月份0-11  
        var currentmonth = currentdate.getmonth();
        //获得当前年份4位年  
        var currentyear = currentdate.getfullyear();
        //获得上一个月的第一天  
        var priormonthfirstday = this.getpriormonthfirstday(currentyear, currentmonth);
        //获得上一月的最后一天  
        var priormonthlastday = new date(priormonthfirstday.getfullyear(), priormonthfirstday.getmonth(), this.getmonthdays(priormonthfirstday.getfullyear(), priormonthfirstday.getmonth()));
        //添加至数组  
        startstop.push(priormonthfirstday);
        startstop.push(priormonthlastday);
        //返回  
        return startstop;
    };


    /**
    * 获得上一周的起止日期
    * **/
    this.getpreviousweek = function () {
        //起止日期数组  
        var startstop = new array();
        //获取当前时间  
        var currentdate = this.getcurrentdate();
        //返回date是一周中的某一天  
        var week = currentdate.getday();
        //返回date是一个月中的某一天  
        var month = currentdate.getdate();
        //一天的毫秒数  
        var millisecond = 1000 * 60 * 60 * 24;
        //减去的天数  
        var minusday = week != 0  week - 1 : 6;
        //获得当前周的第一天  
        var currentweekdayone = new date(currentdate.gettime() - (millisecond * minusday));
        //上周最后一天即本周开始的前一天  
        var priorweeklastday = new date(currentweekdayone.gettime() - millisecond);
        //上周的第一天  
        var priorweekfirstday = new date(priorweeklastday.gettime() - (millisecond * 6));

        //添加至数组  
        startstop.push(priorweekfirstday);
        startstop.push(priorweeklastday);

        return startstop;
    };

    /**
    * 得到上季度的起始日期
    * year 这个年应该是运算后得到的当前本季度的年份
    * month 这个应该是运算后得到的当前季度的开始月份
    * */
    this.getpriorseasonfirstday = function (year, month) {
        var quartermonthstart = 0;
        var spring = 0; //春  
        var summer = 3; //夏  
        var fall = 6;   //秋  
        var winter = 9; //冬  
        //月份从0-11  
        switch (month) {//季度的其实月份  
            case spring:
                //如果是第一季度则应该到去年的冬季  
                year--;
                month = winter;
                break;
            case summer:
                month = spring;
                break;
            case fall:
                month = summer;
                break;
            case winter:
                month = fall;
                break;

        };

        return new date(year, month, 1);
    };

    /**
    * 得到上季度的起止日期
    * **/
    this.getpreviousseason = function () {
        //起止日期数组  
        var startstop = new array();
        //获取当前时间  
        var currentdate = this.getcurrentdate();
        //获得当前月份0-11  
        var currentmonth = currentdate.getmonth();
        //获得当前年份4位年  
        var currentyear = currentdate.getfullyear();
        //上季度的第一天  
        var priorseasonfirstday = this.getpriorseasonfirstday(currentyear, currentmonth);
        //上季度的最后一天  
        var priorseasonlastday = new date(priorseasonfirstday.getfullyear(), priorseasonfirstday.getmonth() + 2, this.getmonthdays(priorseasonfirstday.getfullyear(), priorseasonfirstday.getmonth() + 2));
        //添加至数组  
        startstop.push(priorseasonfirstday);
        startstop.push(priorseasonlastday);
        return startstop;
    };

    /**
    * 得到去年的起止日期
    * **/
    this.getpreviousyear = function () {
        //起止日期数组  
        var startstop = new array();
        //获取当前时间  
        var currentdate = this.getcurrentdate();
        //获得当前年份4位年  
        var currentyear = currentdate.getfullyear();
        currentyear--;
        var prioryearfirstday = new date(currentyear, 0, 1);
        var prioryearlastday = new date(currentyear, 11, 1);
        //添加至数组  
        startstop.push(prioryearfirstday);
        startstop.push(prioryearlastday);
        return startstop;
    };

    return this;
})();

/*
 * 使用:
case "本月":
    $("#startdate").val(daterangeutil.getcurrentmonth()[0].format("yyyy-mm-dd"));
    $("#enddate").val(daterangeutil.getcurrentmonth()[1].format("yyyy-mm-dd"));
    break;
 * 
 */

lt;script type="text/javascript"gt;
function showdate(n)
{
var uom = new date(new date()-0+n*86400000);
uom = uom.getfullyear() + "-" + (uom.getmonth()+1) + "-" + uom.getdate();
return uom;
}
window.alert("今天是："+showdate(0));
window.alert("昨天是："+showdate(-1));
window.alert("明天是："+showdate(1));
window.alert("10天前是："+showdate(-10));
window.alert("5天后是："+showdate(5));
lt;/scriptgt; 

原文：http://www.cnblogs.com/emanlee/archive/2009/04/05/1429666.html

js-时间函数

原文地址：http://www.cnblogs.com/love-zf/p/6219212.html