根据偏移量获取时间

import datetime
def get_month_zone(before_day=1):
    today = datetime.date.today()
    day = today.day
    year = today.year
    month = today.month
    if day > before_day:
        last_day = today - datetime.timedelta(1)
    else:
        last_day = datetime.date(year, month, 1) - datetime.timedelta(1)
    first_day = datetime.date(last_day.year, last_day.month, 1)
    first_day = first_day.strftime("%Y-%m-%d")
    last_day = last_day.strftime("%Y-%m-%d")
    return [first_day, last_day]
print(get_month_zone())