How to get the last day of the month?

StackOverflow

Is there a way using Python"s standard library to easily determine (i.e. one function call) the last day of a given month?

If the standard library doesn"t support that, does the dateutil package support this?

Answer rating: 1252

calendar.monthrange provides this information:

calendar.monthrange(year, month)
    Returns weekday of first day of the month and number of days in month, for the specified year and month.

>>> import calendar
>>> calendar.monthrange(2002, 1)
(1, 31)
>>> calendar.monthrange(2008, 2)  # leap years are handled correctly
(4, 29)
>>> calendar.monthrange(2100, 2)  # years divisible by 100 but not 400 aren"t leap years
(0, 28)

so:

calendar.monthrange(year, month)[1]

seems like the simplest way to go.

Answer rating: 188

If you don"t want to import the calendar module, a simple two-step function can also be:

import datetime

def last_day_of_month(any_day):
    # this will never fail
    # get close to the end of the month for any day, and add 4 days "over"
    next_month = any_day.replace(day=28) + datetime.timedelta(days=4)
    # subtract the number of remaining "overage" days to get last day of current month, or said programattically said, the previous day of the first of next month
    return next_month - datetime.timedelta(days=next_month.day)

Outputs:

>>> for month in range(1, 13):
...     print last_day_of_month(datetime.date(2012, month, 1))
...
2012-01-31
2012-02-29
2012-03-31
2012-04-30
2012-05-31
2012-06-30
2012-07-31
2012-08-31
2012-09-30
2012-10-31
2012-11-30
2012-12-31




Get Solution for free from DataCamp guru