how to get the same day of next month of a given day in python using datetime

Question

i know using datetime.timedelta i can get the date of some days away form given date

daysafter = datetime.date.today() + datetime.timedelta(days=5)
         


        

Answer 1

I often need to need to keep the date as last in month when adding months. I try to add the amount of months to the day after and then remove one day again. If that fails I add one more day until success.

from datetime import timedelta

DAY = timedelta(1)

def add_months(d, months):
    "Add months to date and retain last day in month."
    d += DAY
    # calculate year diff and zero based month
    y, m = divmod(d.month + months - 1, 12)
    try:
        return d.replace(d.year + y, m + 1) - DAY
    except ValueError:
        # on fail return last day in month
        # can't fail on december so just adding one more month
        return d.replace(d.year + y, m + 2, 1) - DAY