How to handle date error with months in datetime.replace in python?

Question

I have the date object which is as follows. Date: 2025-11-30. If I add 3 month to it using following code, it will raise an Exception as follows.

code:

def get_next_n_month_forward(date, n):
    if date.month + n > 12:
        next_month = date.replace(year=date.year + 1,
                                  month=(date.month + n) % 12)
    else:
        next_month = date.replace(month=(date.month + n))
    return next_month

exception:

ValueError: day is out of range for month

As far as I can understand from error it is because february does not have 30th day.

Question: How can I make it set to the last day of the month? !Note: In my case it would be 29th or 28th of February.

using calendar module, https://stackoverflow.com/questions/42950/how-to-get-the-last-day-of-the-month — sushanth, Jun 01 '20 at 07:48
So what is result for 2020-01-31 + 1month ? what do you expectd ? Same day x month later, x*30 days later ? — azro, Jun 01 '20 at 07:49
did not really get about that, can you try anything I would take an example from your suggestions — Madiyor, Jun 01 '20 at 07:52

Pavel Botsman · Accepted Answer · 2020-06-01T08:09:27.050

You can use timedelta object to increase and decrease dates

from datetime import timedelta
import datetime
d = datetime.datetime.today()
new_d = d + timedelta(days=1)

In order to set the date to the last day of month, you can set the date to the 1st of the next month and then decrease it by 1 day:

from datetime import timedelta
import datetime
day = datetime.datetime.today()
prev_month_last_day = day.replace(day=1) - timedelta(days=1)

How to handle date error with months in datetime.replace in python?

1 Answers1