js获取自然周/自然月/自然日开始结束时间戳

/**
 * 获取自然月开始结束时间
 * @param {*} year
 * @param {*} month
 */
function getMonthBeginEnd(year, month) {
    if (~~year === 0 || ~~month === 0) {
        throw new Error('年月参数错误');
    }

    const result = {begin: 0, end: 0};
    const target = new Date();
    target.setFullYear(year);
    target.setMonth(month - 1);
    target.setDate(1);
    target.setHours(0);
    target.setMinutes(0);
    target.setSeconds(0);
    target.setMilliseconds(0);
    result.begin = target.getTime();

    const now = new Date();
    if (target.getFullYear() + target.getMonth() >= now.getFullYear() + now.getMonth()) {
        result.end = now.getTime();
        console.log(result);
        console.log(new Date(result.begin), new Date(result.end));
        return result;
    }

    target.setMonth(month);//当月的下个月1日 0时0分0秒
    target.setSeconds(-1);//前1秒,即昨天最后1秒钟,也就是上个月的最后一秒钟
    result.end = target.getTime();

    console.log(result);
    console.log(new Date(result.begin), new Date(result.end));
    return result;
}
/**
 * 获取自然日开始结束时间
 * @param {*} year
 * @param {*} month
 * @param {*} date
 */
function getDateBeginEnd(year, month, date) {
    if (~~year === 0 || ~~month === 0 || ~~date === 0) {
        throw new Error('年月日参数错误');
    }

    const result = {begin: 0, end: 0};
    const target = new Date();
    target.setFullYear(year);
    target.setMonth(month - 1);
    target.setDate(date);
    target.setHours(0);
    target.setMinutes(0);
    target.setSeconds(0);
    target.setMilliseconds(0);
    result.begin = target.getTime();
    const targetDateCount = target.getFullYear() + target.getMonth() + target.getDate();

    const now = new Date();
    const nowDateCount = now.getFullYear() + now.getMonth() + now.getDate();
    if (targetDateCount >= nowDateCount) {
        result.end = now.getTime();
        console.log(0, result);
        console.log(new Date(result.begin), new Date(result.end));
        return result;
    }

    target.setDate(target.getDate() + 1);//次日0时0分0秒
    target.setSeconds(-1);//前1秒,即当日最后1秒钟
    result.end = target.getTime();

    console.log(1, result);
    console.log(new Date(result.begin), new Date(result.end));
    return result;
}

/**
 * 获取自然周开始结束时间
 * @param {*} year
 * @param {*} month
 * @param {*} number 第几周
 */
function getWeekByMonth(year, month, number) {
    const weekCount = getWeekCountInMonth(year, month);
    const result = {begin: 0, end: 0, list: weekCount};
    const target = new Date();
    target.setFullYear(year);
    target.setMonth(month - 1);
    target.setDate(1);
    target.setHours(0);
    target.setMinutes(0);
    target.setSeconds(0);
    target.setMilliseconds(0);
    let targetDay = target.getDay();
    targetDay = targetDay === 0 ? 7 : targetDay;

    if (number === weekCount[0]) {
        console.log(month + '月第' + number + '周起始', target);
        result.begin = target.getTime();
        target.setDate(target.getDate() + (7 - targetDay));//设置到周日最后一秒
        target.setHours(23);
        target.setMinutes(59);
        target.setSeconds(59);
        target.setMilliseconds(0);
        console.log(month + '月第' + number + '周截止', target);
        result.end = target.getTime();
        console.log(result);
        return result;
    }

    target.setDate(target.getDate() + (7 - targetDay) + 1);//对其到周一,设置到第二个周一0时0分0秒
    target.setDate(target.getDate() + 7 * (number - 2));//设置到第n周周日
    console.log(month + '月第' + number + '周起始', target);
    result.begin = target.getTime();

    if (number === weekCount[weekCount.length - 1]) {
        target.setMonth(month);//次月1日
        target.setDate(1);
        target.setHours(0);
        target.setMinutes(0);
        target.setSeconds(0);
        target.setMilliseconds(-1);//向前到当月最后1毫秒
        result.end = target.getTime();
        console.log(month + '月第' + number + '周截止', target);
        console.log(result);
        return result;
    }

    target.setDate(target.getDate() + 6);//设置到第n周周日
    target.setHours(23);
    target.setMinutes(59);
    target.setSeconds(59);
    target.setMilliseconds(0);
    result.end = target.getTime();
    console.log(month + '月第' + number + '周截止', target);
    console.log(result);
    return result;
}

/**
 * 获取每月有多少周
 * @param {*} year
 * @param {*} month
 */
function getWeekCountInMonth(year, month) {
    const list = [];
    const target = new Date();
    let offset = 1;
    target.setFullYear(year);
    target.setMonth(month - 1);
    target.setDate(1);
    target.setHours(0);
    target.setMinutes(0);
    target.setSeconds(0);
    target.setMilliseconds(0);
    let targetDay = target.getDay();
    targetDay = targetDay === 0 ? 7 : targetDay;

    if (targetDay !== 1) {
        console.log(targetDay);
        list.push(offset);
        offset = offset + 1;
        target.setDate(target.getDate() + (7 - targetDay) + 1);//对齐到周一
    }

    for (let i = offset; i <= 5; i++) {
        list.push(offset);
        offset = offset + 1;
        target.setDate(target.getDate() + 7);//设置到次周一0时分秒
        target.setMilliseconds(-1);//向前1毫秒到本周最后1毫秒
        console.log(target);
        if ((target.getMonth() + 1) !== month) {
            break;
        }
    }
    console.log(month + '月周数', list);
    return list;
}

/**
 * 获取上一月时间
 * @param {} date
 */
function getPreMonth (date) {
    var _date = dateFormat('YYYY-MM', new Date(date));
    var arr = _date.split('-');
    var year = arr[0]; // 获取当前日期的年份
    var month = arr[1]; // 获取当前日期的月份
    var day = arr[2]; // 获取当前日期的日
    var days = new Date(year, month, 0);
    days = days.getDate(); // 获取当前日期中月的天数
    var year2 = year;
    var month2 = parseInt(month) - 1;
    if (month2 === 0) {
        year2 = parseInt(year2) - 1;
        month2 = 12;
    }
    var day2 = day;
    var days2 = new Date(year2, month2, 0);
    days2 = days2.getDate();
    if (day2 > days2) {
        day2 = days2;
    }
    if (month2 < 10) {
        month2 = '0' + month2;
    }
    var t2 = year2 + '-' + month2;
    return t2;
}
/**
 * 获取下一月时间
 * @param {时间} date
 */
function getNextMonth (date) {
    var _date = dateFormat('YYYY-MM', new Date(date));
    var arr = _date.split('-');
    var year = arr[0]; // 获取当前日期的年份
    var month = arr[1]; // 获取当前日期的月份
    var day = arr[2]; // 获取当前日期的日
    var days = new Date(year, month, 0);
    days = days.getDate(); // 获取当前日期中的月的天数
    var year2 = year;
    var month2 = parseInt(month) + 1;
    if (month2 === 13) {
        year2 = parseInt(year2) + 1;
        month2 = 1;
    }
    var day2 = day;
    var days2 = new Date(year2, month2, 0);
    days2 = days2.getDate();
    if (day2 > days2) {
        day2 = days2;
    }
    if (month2 < 10) {
        month2 = '0' + month2;
    }

    var t2 = year2 + '-' + month2;
    return t2;
}
/**
 * 格式化时间
 * @param {YYYY-MM-DD hh:mm:ss} String
 * @param {时间} date
 */
function dateFormat (fmt, date) {
    date = new Date(date);
    let ret;
    let opt = {
        'Y+': date.getFullYear().toString(), // 年
        'M+': (date.getMonth() + 1).toString(), // 月
        'D+': date.getDate().toString(), // 日
        'h+': date.getHours().toString(), // 时
        'm+': date.getMinutes().toString(), // 分
        's+': date.getSeconds().toString() // 秒
    // 有其他格式化字符需求可以继续添加，必须转化成字符串
    };
    for (let k in opt) {
        ret = new RegExp('(' + k + ')').exec(fmt);
        if (ret) {
            fmt = fmt.replace(ret[1], (ret[1].length === 1) ? (opt[k]) : (opt[k].padStart(ret[1].length, '0')));
        }
    }
    return fmt;
}
// getMonthBeginEnd(2019, 9);
// getDateBeginEnd(2019, 10, 16);
// getWeekByMonth(2019, 10, 5);

原文地址：https://www.cnblogs.com/Lewiskycc/p/11697586.html