dateutil

powerful extensions to the standard datetime module

Tip

Check out Delorean (Time Travel Made Easy) (Delorean Documentation)

For python 2.x:

pip install python-dateutil==1.5

Import

from datetime import date
from dateutil.relativedelta import relativedelta

parse

from dateutil import parser

result = parser.parse(date_as_str)

Tip

parser.parse returns a datetime. To set this datetime to the first or last second in the day, see Combine

rrule

Django timezone:

from dateutil.rrule import MONTHLY
from dateutil.rrule import rrule
from django.utils import timezone

result = rrule(MONTHLY, bymonthday=(-1,), dtstart=timezone.now())
result.after(timezone.now())

Tip

To get rrule to work with timezone, then set dtstart to a timezone aware date/time.

Sample

Iterate

from dateutil.rrule import DAILY, rrule

for day in rrule(DAILY, dtstart=date(2015, 1, 1), until=date(2015, 1, 3)):
    print(day)

>>> 2015-01-01 00:00:00
>>> 2015-01-02 00:00:00
>>> 2015-01-03 00:00:00

Specific

First day of the month:

d = date(2013, 9, 22)

>>> d + relativedelta(day=1)
datetime.date(2013, 9, 1)

First day of the next month:

>>> d + relativedelta(months=+1, day=1)
datetime.date(2013, 10, 1)

First day of the previous month:

>>> d + relativedelta(months=-1, day=1)
datetime.date(2013, 8, 1)

Last day of the previous month:

>>> d + relativedelta(day=1, days=-1)
datetime.date(2013, 8, 31)

Last day of this month:

>>> d + relativedelta(months=+1, day=1, days=-1)

Monday:

>>> from dateutil.relativedelta import MO, relativedelta
>>> d + relativedelta(weekday=MO(-1))

Tomorrow:

date.today() + relativedelta(days=1)