获得x个月之后或之前的下一个日期的一般函数。

from datetime import date

def after_month(given_date, month):
    yyyy = int(((given_date.year * 12 + given_date.month) + month)/12)
    mm = int(((given_date.year * 12 + given_date.month) + month)%12)

    if mm == 0:
        yyyy -= 1
        mm = 12
    return given_date.replace(year=yyyy, month=mm)


if __name__ == "__main__":
    today = date.today()
    print(today)

    for mm in [-12, -1, 0, 1, 2, 12, 20 ]:
        next_date = after_month(today, mm)
        print(next_date)

一个简单的建议是《绿箭侠》

PIP安装箭头

>>> import arrow

>>> arrow.now().date()
datetime.date(2019, 6, 28)
>>> arrow.now().shift(months=6).date()
datetime.date(2019, 12, 28)

我使用这个函数来更改年和月，但保留日:

def replace_month_year(date1, year2, month2):
    try:
        date2 = date1.replace(month = month2, year = year2)
    except:
        date2 = datetime.date(year2, month2 + 1, 1) - datetime.timedelta(days=1)
    return date2

你应该这样写:

new_year = my_date.year + (my_date.month + 6) / 12
new_month = (my_date.month + 6) % 12
new_date = replace_month_year(my_date, new_year, new_month)

这是我想到的。它移动了正确的月份和年份，但忽略了天数(这是我的情况所需要的)。

import datetime

month_dt = 4
today = datetime.date.today()
y,m = today.year, today.month
m += month_dt-1
year_dt = m//12
new_month = m%12
new_date = datetime.date(y+year_dt, new_month+1, 1)

使用Python标准库，即没有dateutil或其他，并解决“2月31日”问题:

import datetime
import calendar

def add_months(date, months):
    months_count = date.month + months

    # Calculate the year
    year = date.year + int(months_count / 12)

    # Calculate the month
    month = (months_count % 12)
    if month == 0:
        month = 12

    # Calculate the day
    day = date.day
    last_day_of_month = calendar.monthrange(year, month)[1]
    if day > last_day_of_month:
        day = last_day_of_month

    new_date = datetime.date(year, month, day)
    return new_date

测试:

>>>date = datetime.date(2018, 11, 30)

>>>print(date, add_months(date, 3))
(datetime.date(2018, 11, 30), datetime.date(2019, 2, 28))

>>>print(date, add_months(date, 14))
(datetime.date(2018, 12, 31), datetime.date(2020, 2, 29))

Dateutil包实现了这样的功能。但要知道，这将是天真的，因为其他人已经指出。