How to calculate next Friday?

Question

How can I calculate the date of the next Friday?

Answer 1

Just for readability I would use strftime('%A') rather than weekday():

import datetime

d = datetime.date.today()

while d.strftime('%a') != 'Fri':
    d += datetime.timedelta(1)

Answer 2

You can calculate any next day dates using these this code below.

from datetime import datetime as dt
from datetime import timedelta

def get_weekday(day):
    days  = ["mon","tue","wed","thu","fri","sat","sun"]
    return days.index(day) + 1

def get_next_dayofweek_datetime(date_time, dayofweek):
    start_time_w = date_time.isoweekday()
    target_w = get_weekday(dayofweek)
    if start_time_w < target_w:
      day_diff = target_w - start_time_w
    else:
        day_diff = 7 - (start_time_w - target_w)

    return date_time + timedelta(days=day_diff)

def get_next_n_weekends_dates(date_time, weekday, n=2):
  days_list = []
  week_date_time = date_time
  while n > 0:
      week_date_time = get_next_dayofweek_datetime(week_date_time, weekday)
      days_list.append(week_date_time)
      n = n -1
  return  days_list

start_time = dt.strptime("2020-02-01 20:20:00", "%Y-%m-%d %H:%M:%S") # wednesday


print(get_next_dayofweek_datetime(start_time, "thu"))
print(get_next_dayofweek_datetime(start_time, "fri"))
print(get_next_dayofweek_datetime(start_time, "sat"))
print(get_next_dayofweek_datetime(start_time, "sun"))
print(get_next_dayofweek_datetime(start_time, "mon"))
print(get_next_dayofweek_datetime(start_time, "tue"))
print(get_next_dayofweek_datetime(start_time, "wed"))
print(get_next_dayofweek_datetime(start_time, "thu"))

print("get next two fridays or mote ")
print(get_next_n_weekends_dates(start_time, "fri", 2))

output:

2020-02-06 10:20:00
2020-02-07 10:20:00
2020-02-08 10:20:00
2020-02-02 10:20:00
2020-02-03 10:20:00
2020-02-04 10:20:00
2020-02-05 10:20:00
2020-02-06 10:20:00
get next two fridays or mote 
[datetime.datetime(2020, 2, 7, 10, 20), datetime.datetime(2020, 2, 14, 10, 20)]

Answer 3

A certain improvement on @taymon`s answer:

today = datetime.date.today()
friday = today + datetime.timedelta( (4-today.weekday()) % 7 )

4 is Friday's weekday (0 based, counting from Monday).
( (4-today.weekday()) % 7) is the number of days till next friday (% is always non-negative).

After seeing @ubuntu's answer, I should add two things:
1. I'm not sure if Friday=4 is universally true. Some people start their week on Sunday.
2. On Friday, this code returns the same day. To get the next, use (3-today.weekday())%7+1. Just the old x%n to ((x-1)%n)+1 conversion.

Answer 4

To start off, you'll need the datetime library:

import datetime

Then you need a starting date; that is, today.

d = datetime.date.today()

Starting from there, you'll want to keep going forward until you reach Friday. The date.weekday method represents Monday through Sunday as 0 through 6, so:

while d.weekday() != 4:

If the current day isn't Friday, you'll have to add a day, one at a time. To add an interval of time to a date object, you use a timedelta object.

    d += datetime.timedelta(1)

Put it all together, and d will ultimately contain a date object representing next Friday. Note that if today is Friday, this code will produce today; you can tweak it if you need it to produce next Friday instead.

Answer 5

import datetime 
def next_fri_13(start_date):
        next_friday = start_date + datetime.timedelta(((4 - today.weekday()) % 7))
        while True:
            if next_friday.day==13:
                thirteen_friday = next_friday
                break
            else:
                next_date = next_friday + datetime.timedelta(days=1)
                next_friday = next_date + datetime.timedelta(((4 -next_date.weekday())% 7))
        return thirteen_friday

    r = next_fri_13(datetime.date(2020, 2, 11)) print(r)

Answer 6

Here is how you could do it using dateutil:

import datetime as DT
import dateutil.relativedelta as REL
today = DT.date.today()
print(today)
# 2012-01-10

rd = REL.relativedelta(days=1, weekday=REL.FR)
next_friday = today + rd
print(next_friday)
# 2012-01-13

(The days = 1 argument ensures that the "next Friday" is not the same as today in case today happens to be a Friday.)