JavaScript | 获取指定范围时间

获取近一周的时间

export const getLastWeek = () => {
    let now = new Date();
    let year = now.getFullYear();
    let month = now.getMonth() + 1;//0-11表示1-12月
    let day = now.getDate();
    
    let dateObj = {};
    dateObj.now = year + '-' + ( month < 10 ? '0'+ month : month) + '-' + (day < 10 ? '0' + day : day);

    if(day - 7 <= 0){ //如果在当月7日之前
        let lastMonthDay = new Date(year, (parseInt(month) - 1), 0).getDate(); //1周前所在月的总天数
        if(month - 1 <= 0){ //如果在当年的1月份
            dateObj.last = (year - 1) + '-' + 12 + '-' + (31 - (7 - day));
        }else{
            dateObj.last = year + '-' + (month - 1) + '-' + (lastMonthDay - (7 - day));
        }
    }else{
        dateObj.last = year + '-' + (month < 10 ? '0'+ month : month) + '-' + ((day -6) < 10 ? '0' + (day -6) : (day -6));
    }
    return dateObj;

}

获取近几个月的时间

export const getPreMonthDay = (date, monthNum) => {

    let dateArr = date.split('-')

    let year = dateArr[0] //获取当前日期的年份

    let month = dateArr[1] //获取当前日期的月份

    let day = dateArr[2] //获取当前日期的日    

    let days = new Date(year, month, 0)

    days = days.getDate() //获取当前日期中月的天数
    
    let year2 = year
    
    let month2 = parseInt(month) - monthNum

    if (month2 <= 0) {

        year2 = parseInt(year2) - parseInt(month2 / 12 == 0 ? 1 : Math.abs(parseInt(month2 / 12)) + 1)

        month2 = 12 - (Math.abs(month2) % 12)

    }
    let day2 = day

    let days2 = new Date(year2, month2, 0)

    days2 = days2.getDate()

    if (day2 > days2) {

        day2 = days2

    }
    if (month2 < 10) {

        month2 = '0' + month2

    }
    let t2 = year2 + '-' + month2 + '-' + day2;

    let dateObj = {

        now: date,

        last: t2

    }
    return dateObj

}

getPreMonthDay(‘2020-05-08’，1) //获取最近一个月的日期