_add_holiday* method documentation

[maxrausch]

Is there any documentation page that explains the _add_holiday method where you add a specific day in each. I was looking through the code and the logic seems to be based on a regex of the name and ends up calling _get_nth_weekday_from eventually but there are no examples in the document that explain how to call these functions for creating a new customized exchange holiday calendar.

[arkid15r]

Hi @maxrausch,
you're absolutely right -- there is no documentation for these methods. You can blame me for that. I implemented those methods as a part of syntactic sugar improvements for PH needs. You can still use the "old fashioned" way for adding holidays directly, e.g. entity[dt] = "My Holiday". Here you can find the implementation with my comments. Essentially the code supports 4 different cases (from most to least frequently used):

• <month> <day> patterns (e.g., _add_holiday_jun_15()).
• <last/nth> <weekday> of <month> patterns (e.g., _add_holiday_last_mon_of_aug() or _add_holiday_3rd_fri_of_aug()).
• <n> day(s) <past/prior> <last/<nth> <weekday> of <month> patterns (e.g., _add_holiday_1_day_past_1st_fri_of_aug() or _add_holiday_5_days_prior_last_fri_of_aug()).
• <nth> <weekday> <before/from> <month> <day> patterns (e.g., _add_holiday_1st_mon_before_jun_15() or _add_holiday_1st_mon_from_jun_15()).

I'll create an issue for documenting this.

[maxrausch]

Thank you! This is very helpful. I don't think I understood the "old fashion" way but I re-read this section and makes sense now: https://python-holidays.readthedocs.io/en/latest/examples.html#creating-custom-holidays-or-augmenting-existing-ones-with-private-ones