How to get last Friday?

Question

The code below should return last Friday, 16:00:00. But it returns Friday of previous week. How to fix that?

now = datetime.datetime.now()
test = (now - date         


        

Answer 1

The principle is the same as in your other question.

Get the friday of the current week and, if we are later, subtract one week.

import datetime
from datetime import timedelta
now = datetime.datetime.now()
today = now.replace(hour=16,minute=0,second=0,microsecond=0)
sow = (today - datetime.timedelta(days=now.weekday()))
this_friday = sow + timedelta(days=4)
if now > this_friday:
     test = this_friday
else:
     test = this_friday + timedelta(weeks=-1)

Answer 2

Could be lame but to me simplest. Get the last day of the current month and start checking in a loop (which wouldn't cost anything since max loops before finding last friday is 7) for friday. if last day is not friday decrement and the check the day before.

import calendar
from datetime import datetime, date

def main():
    year = datetime.today().year    
    month = datetime.today().month  
    x = calendar.monthrange(year,month)
    lastday = x[1]
    while True:
        z = calendar.weekday(year, month, lastday)
        if z != 4:
            lastday -= 1
        else:
            print(date(year,month,lastday))
            break

if __name__ == "__main__":
    main()

Answer 3

As in the linked question, you need to use datetime.date objects instead of datetime.datetime. To get a datetime.datetime in the end, you can use datetime.datetime.combine():

import datetime

current_time = datetime.datetime.now()

# get friday, one week ago, at 16 o'clock
last_friday = (current_time.date()
    - datetime.timedelta(days=current_time.weekday())
    + datetime.timedelta(days=4, weeks=-1))
last_friday_at_16 = datetime.datetime.combine(last_friday, datetime.time(16))

# if today is also friday, and after 16 o'clock, change to the current date
one_week = datetime.timedelta(weeks=1)
if current_time - last_friday_at_16 >= one_week:
    last_friday_at_16 += one_week

Answer 4

Simplest solution without dependency:

from datetime import datetime, timedelta

def get_last_friday():
    now = datetime.now()
    closest_friday = now + timedelta(days=(4 - now.weekday()))
    return (closest_friday if closest_friday < now
            else closest_friday - timedelta(days=7))

Answer 5

The dateutil library is great for things like this:

>>> from datetime import datetime
>>> from dateutil.relativedelta import relativedelta, FR
>>> datetime.now() + relativedelta(weekday=FR(-1))
datetime.datetime(2012, 9, 28, 9, 42, 48, 156867)

Answer 6

This was borrowed from Jon Clements, but is the full solution:

>>> from datetime import datetime
>>> from dateutil.relativedelta import relativedelta, FR
>>> lastFriday = datetime.now() + relativedelta(weekday=FR(-1))
>>> lastFriday.replace(hour=16,minute=0,second=0,microsecond=0)
datetime.datetime(2012, 9, 28, 16, 0, 0, 0)