概述

根据当前时间获取上个月月份日期和下个月月份日期。

上个月

// 上个月
const getPreMonth = date => {
    var [year, month, day] = date.split('-'); // 分割数组获取年月日
    var oldDays = new Date(year, month, 0);
    oldDays = oldDays.getDate(); //获取当前日期中月的天数
    var newYear = year;
    var newMonth = parseInt(month) - 1;
    if (newMonth == 0) {
        newYear = parseInt(newYear) - 1;
        newMonth = 12;
    }
    var newDay = day;
    var newDays = new Date(newYear, newMonth, 0);
    newDays = newDays.getDate();
    if (newDay > newDays) {
        newDay = newDays;
    }
    if (newMonth < 10) { // 小于10补0
        newMonth = '0' + newMonth;
    }
    var newDates = newYear + '-' + newMonth + '-' + newDay;
    return newDates;
};

下个月

const getNextMonths = date => {
    var [year, month, day] = date.split('-'); // 分割数组获取年月日
    var oldDays = new Date(year, month, 0);
    oldDays = oldDays.getDate(); //获取当前日期中月的天数

    var newYear = year;
    var newMonth = parseInt(month) + 1;
    if (newMonth == 13) {
        newYear = parseInt(newYear) + 1;
        newMonth = 1;
    }
    var newDay = day;
    var newDays = new Date(newYear, newMonth, 0);
    newDays = newDays.getDate();
    if (newDay > newDays) {
        newDay = newDays;
    }
    if (newMonth < 10) {
        newMonth = '0' + newMonth;
    }

    var newDates = newYear + '-' + newMonth + '-' + newDay;
    return newDates;
};