Custom holiday observance in Pandas tseries Holiday

Question

I want to create a class of holidays of Christmas and the day after, but I encounter a problem. There is one out of three special cases I cannot quite solve it.

Case1: Christmas is Friday, then the Holidays are Friday(12-25) and Saturday(12-26)(solved). This case happens in 2020

Case2: Christmas is Saturday, then the Holidays are Saturday(12-25) and Monday(12-27)(solved). This case happens in 2021

Case3: Christmas is Sunday, then the Holidays are Monday(12-26) and Tuesday(12-27)(unsolved). This case happens in 2016

Case 3 could be solved if observance= monday_to_tuesday was available, but sadly it isn't, which is why I am here asking for help, since the pandas tseries user guide doesn't say anything about creating a custom observance or anything about the situation where the observance is from any weekday.

The class I am working on is the following:

---

from pandas.tseries.holiday import Holiday, sunday_to_monday, AbstractHolidayCalendar

import pandas as pd
import datetime as dt

class MyHolidays(AbstractHolidayCalendar):
    rules = [Holiday('Christmas',month=12,day=25, observance= sunday_to_monday),
             Holiday('Boxingday',month=12,day=26, observance= sunday_to_monday)]

cal= MyHolidays()

if __name__ == '__main__':
    myholidays =cal.holidays(start = dt.datetime(2016,1,1), end=dt.datetime(2021,12,31))
    temp_s = pd.Series(myholidays)
    print(temp_s)

Is there anyway to solve my problem? Thank you in advance

Answer 1

You can roll your own observance function following the existing ones . They are just regular python functions, so you can also use a lambda as shown here:

from pandas.tseries.holiday import Holiday, sunday_to_monday, AbstractHolidayCalendar

import pandas as pd
import datetime as dt

class MyHolidays(AbstractHolidayCalendar):
    rules = [Holiday('Christmas',month=12,day=25, observance= sunday_to_monday),
             Holiday('Boxingday',month=12,day=26, observance= lambda d: d + dt.timedelta(1) if d.weekday() == 0 or d.weekday() == 6 else d )]

cal= MyHolidays()

if __name__ == '__main__':
    myholidays =cal.holidays(start = dt.datetime(2016,1,1), end=dt.datetime(2021,12,31))
    temp_s = pd.Series(myholidays)
    print(temp_s)

Output:

0    2016-12-26
1    2016-12-27
2    2017-12-25
3    2017-12-26
4    2018-12-25
5    2018-12-26
6    2019-12-25
7    2019-12-26
8    2020-12-25
9    2020-12-26
10   2021-12-25
11   2021-12-27