Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2881
File: tests/countries/test_belgium.py:28-30
Timestamp: 2025-09-20T12:21:50.877Z
Learning: Belgium holidays implementation currently lacks a start_year attribute. In tests/countries/test_belgium.py, do not suggest adding test_no_holidays methods that rely on start_year until the start_year attribute is introduced to Belgium's holiday implementation.

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2881
File: tests/countries/test_french_polynesia.py:19-22
Timestamp: 2025-11-08T05:09:56.159Z
Learning: In the vacanza/holidays project's test framework (PR #2881 onwards), the base class CommonCountryTests provides a default test_no_holidays implementation that automatically tests years=start_year - 1 for standard PUBLIC category cases. Individual country test files should only override test_no_holidays when the country supports additional non-PUBLIC categories (GOVERNMENT, WORKDAY, OPTIONAL, etc.) with different start years requiring separate validation.

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2642
File: holidays/countries/france.py:300-319
Timestamp: 2025-06-18T10:21:01.376Z
Learning: In the France holidays implementation, legislative years for holiday changes should be hard-coded rather than extracted into constants, as this maintains consistency with the existing codebase pattern and provides historical accuracy for specific legislative acts.

Learnt from: KJhellico
Repo: vacanza/holidays PR: 2777
File: holidays/countries/gambia.py:120-122
Timestamp: 2025-08-03T13:48:11.910Z
Learning: When reviewing holiday implementations in the holidays library, defer to the maintainers' choice of start years for specific holiday policies, as they likely have access to more reliable primary sources and official documentation than what can be found through web searches.

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2874
File: tests/countries/test_taiwan.py:379-381
Timestamp: 2025-08-31T09:54:22.093Z
Learning: In Taiwan's holiday system, some holidays like Women's Day can appear in multiple categories simultaneously. Women's Day appears in the WORKDAY category for regular March 8th dates but also has special observed dates in the OPTIONAL category (1998-2000) when it was moved before Tomb-Sweeping Day. The test cases correctly reflect this dual-category behavior.

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2881
File: tests/countries/test_south_africa.py:22-22
Timestamp: 2025-09-14T04:41:10.139Z
Learning: South Africa's observed holiday system only started in 1995, so in tests/countries/test_south_africa.py, using years_non_observed=range(1995, 2050) is intentional to limit testing to years where observed holidays actually exist, improving both correctness and performance.

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2654
File: holidays/locale/de/LC_MESSAGES/CV.po:37-40
Timestamp: 2025-07-04T08:54:03.203Z
Learning: In German localization for Cape Verde holidays, "Dia da Nacionalidade e dos Heróis Nacionais" is translated as "Tag der Nationalhelden" (not "Tag der Nationalität und der Nationalhelden") based on authoritative German language sources about Cape Verde holidays, specifically from feelcaboverde.com.

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2654
File: holidays/locale/de/LC_MESSAGES/CV.po:37-40
Timestamp: 2025-07-04T08:54:03.203Z
Learning: In German localization for Cape Verde holidays, "Dia da Nacionalidade e dos Heróis Nacionais" is translated as "Tag der Nationalhelden" (not "Tag der Nationalität und der Nationalhelden") based on authoritative German language sources about Cape Verde holidays, specifically from feelcaboverde.com.

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2642
File: holidays/countries/france.py:178-180
Timestamp: 2025-06-18T10:26:50.180Z
Learning: In the France holidays implementation, the _populate_subdiv_57_public_holidays() (Moselle) and _populate_subdiv_6ae_public_holidays() (Alsace) methods are functionally identical, both adding Good Friday (≥1893) and Saint Stephen's Day (≥1892) with the same legal references from August 16th, 1892. Therefore, for the deprecated "Alsace-Moselle" subdivision, calling either method produces the same result.

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2642
File: holidays/countries/france.py:178-182
Timestamp: 2025-06-18T10:18:59.447Z
Learning: In the France holidays implementation, deprecated subdivision names like "Alsace-Moselle" and "Saint-Barthélémy" are handled through explicit conditionals in _populate_public_holidays() that map them to their corresponding new subdivision-specific holiday population methods, providing backward compatibility while users transition to the new ISO codes.

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2942
File: holidays/countries/south_africa.py:91-98
Timestamp: 2025-09-18T07:01:12.236Z
Learning: In the holidays library South Africa implementation, inline ternary operators for holiday name selection (like "Republic Day" if self._year >= 1961 else "Union Day") are intentionally kept inline rather than extracted to separate variables, as this structure is designed in preparation for future localization (l10n) support where the contextual relationship between conditions and translatable strings needs to be preserved.

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2881
File: tests/countries/test_colombia.py:45-61
Timestamp: 2025-09-20T15:37:21.301Z
Learning: In Colombia's holiday system, movable observed holidays were only introduced from 1984 onwards. Before this date, holidays that later became movable (like Saint Joseph's Day) existed as regular holidays from their introduction year, but had no observed variant system. The years_non_observed parameter in Colombia tests reflects this 1984 start date for the observed holiday system.

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2881
File: tests/countries/test_algeria.py:28-30
Timestamp: 2025-09-18T03:19:23.722Z
Learning: In the vacanza/holidays project, tests now use self.start_year and self.end_year from the TestCase class instead of country-specific aliases (like DZ.start_year) for start_year and end_year references. This approach provides the test framework with better control over test year ranges rather than being tied to specific country start years.

Learnt from: KJhellico
Repo: vacanza/holidays PR: 2653
File: holidays/locale/th/LC_MESSAGES/TW.po:17-21
Timestamp: 2025-06-21T18:06:50.027Z
Learning: KJhellico's username includes a tilde character (~) as part of their nickname (appears as "~Jhellico" in Last-Translator headers), which is intentional formatting and not an error.

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2881
File: tests/countries/test_belgium.py:28-30
Timestamp: 2025-09-20T12:21:50.877Z
Learning: Belgium holidays implementation currently lacks a start_year attribute. In tests/countries/test_belgium.py, do not suggest adding test_no_holidays methods that rely on start_year until the start_year attribute is introduced to Belgium's holiday implementation.

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2609
File: holidays/countries/nauru.py:48-50
Timestamp: 2025-06-14T11:05:21.250Z
Learning: In the holidays library, newer implementations use `start_year` to indicate the earliest year with complete holiday data coverage, not necessarily the first year a holiday existed. If a holiday system starts partway through a year (like Nauru's Public Holidays Act starting Jan 31, 1968), the start_year should be set to the following year (1969) to ensure users get full annual holiday coverage.

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2609
File: holidays/countries/nauru.py:57-60
Timestamp: 2025-06-14T11:04:31.180Z
Learning: In the holidays library, the base `HolidayBase._populate()` method already includes a guard clause that prevents holiday population methods like `_populate_public_holidays()` from being called when the year is before `start_year` or after `end_year`. Therefore, individual country implementations do not need to add their own guard clauses for years before independence or other start dates.

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2881
File: tests/countries/test_algeria.py:28-30
Timestamp: 2025-09-18T03:19:23.722Z
Learning: In the vacanza/holidays project, tests now use self.start_year and self.end_year from the TestCase class instead of country-specific aliases (like DZ.start_year) for start_year and end_year references. This approach provides the test framework with better control over test year ranges rather than being tied to specific country start years.

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2881
File: tests/countries/test_bosnia_and_herzegovina.py:21-24
Timestamp: 2025-09-10T16:17:30.428Z
Learning: Bosnia and Herzegovina holidays implementation currently lacks a start_year attribute. In tests/countries/test_bosnia_and_herzegovina.py, using cls.full_range = range(2000, 2050) is intentional to bound assertions and setup. Do not suggest replacing it with harness default full_range until start_year is introduced.

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2881
File: tests/countries/test_south_africa.py:22-22
Timestamp: 2025-09-14T04:41:10.139Z
Learning: South Africa's observed holiday system only started in 1995, so in tests/countries/test_south_africa.py, using years_non_observed=range(1995, 2050) is intentional to limit testing to years where observed holidays actually exist, improving both correctness and performance.

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2881
File: tests/countries/test_paraguay.py:134-139
Timestamp: 2025-09-17T09:07:56.459Z
Learning: In the vacanza/holidays project, for holidays that start from a specific year (not the country's start_year), the standard pattern is to use `range(specific_year, self.end_year)` rather than `self.full_range` with year conditions. This maintains consistency across the codebase and clearly separates the holiday period from the pre-holiday period using `assertNoHolidayName(name, range(self.start_year, specific_year))`.

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2642
File: holidays/countries/france.py:300-319
Timestamp: 2025-06-18T10:21:01.376Z
Learning: In the France holidays implementation, legislative years for holiday changes should be hard-coded rather than extracted into constants, as this maintains consistency with the existing codebase pattern and provides historical accuracy for specific legislative acts.

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2881
File: tests/countries/test_french_polynesia.py:19-22
Timestamp: 2025-11-08T05:09:56.159Z
Learning: In the vacanza/holidays project's test framework (PR #2881 onwards), the base class CommonCountryTests provides a default test_no_holidays implementation that automatically tests years=start_year - 1 for standard PUBLIC category cases. Individual country test files should only override test_no_holidays when the country supports additional non-PUBLIC categories (GOVERNMENT, WORKDAY, OPTIONAL, etc.) with different start years requiring separate validation.

Learnt from: KJhellico
Repo: vacanza/holidays PR: 2763
File: holidays/groups/mandaean.py:58-69
Timestamp: 2025-08-08T21:52:45.289Z
Learning: HolidayBase in the holidays library has a default end_year = 2100 (defined as DEFAULT_END_YEAR in holidays/constants.py), which is automatically inherited by all country classes unless explicitly overridden.

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2642
File: holidays/countries/france.py:178-180
Timestamp: 2025-06-18T10:26:50.180Z
Learning: In the France holidays implementation, the _populate_subdiv_57_public_holidays() (Moselle) and _populate_subdiv_6ae_public_holidays() (Alsace) methods are functionally identical, both adding Good Friday (≥1893) and Saint Stephen's Day (≥1892) with the same legal references from August 16th, 1892. Therefore, for the deprecated "Alsace-Moselle" subdivision, calling either method produces the same result.

Learnt from: KJhellico
Repo: vacanza/holidays PR: 2386
File: holidays/countries/nepal.py:24-26
Timestamp: 2025-03-30T20:18:46.006Z
Learning: In the holidays library, country classes do not directly implement `_populate()`. Instead, they implement specialized methods like `_populate_public_holidays()`, and the base class `HolidayBase` handles the orchestration by calling these specialized methods.

Learnt from: KJhellico
Repo: vacanza/holidays PR: 2386
File: holidays/countries/nepal.py:52-60
Timestamp: 2025-04-13T20:42:13.152Z
Learning: In the holidays library, country classes follow a consistent initialization pattern: first explicitly initializing each parent holiday group class with their specific parameters, then calling `super().__init__(*args, **kwargs)` at the end to properly initialize the base `HolidayBase` class.

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2614
File: holidays/countries/guyana.py:78-90
Timestamp: 2025-06-13T12:18:03.539Z
Learning: The holidays codebase now uses the constructor signature pattern `__init__(self, *args, islamic_show_estimated: bool = True, **kwargs)` across country classes.

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2642
File: holidays/countries/french_southern_territories.py:41-44
Timestamp: 2025-06-18T10:07:58.780Z
Learning: Territorial holiday classes that inherit from parent countries (like HolidaysAX from Finland, HolidaysSJ from Norway, HolidaysTF from France) follow a standard pattern of silently overriding self.subdiv in their _populate_public_holidays() method without validation, as this ensures they always use the correct subdivision code for their territory regardless of user input.

Learnt from: ankushhKapoor
Repo: vacanza/holidays PR: 2386
File: holidays/countries/nepal.py:29-34
Timestamp: 2025-03-29T17:55:09.799Z
Learning: In the holidays library, classes with multiple inheritance from various holiday groups (like ChristianHolidays, HinduCalendarHolidays, etc.) should initialize each parent class separately rather than using `super().__init__(*args, **kwargs)` because the parent classes have different parameter requirements. HolidayBase should receive the `*args, **kwargs` while other holiday group classes typically don't accept parameters like `observed`.

Learnt from: KJhellico
Repo: vacanza/holidays PR: 2606
File: holidays/countries/faroe_islands.py:62-67
Timestamp: 2025-06-15T15:24:53.055Z
Learning: The `HolidayBase` class uses `__getattr__` to dynamically implement `_add_holiday_*` methods through pattern matching, including patterns like `_add_holiday_<n>_days_past_easter`, `_add_holiday_<month>_<day>`, and various weekday-relative patterns. Methods like `_add_holiday_26_days_past_easter` are not explicitly defined but are dynamically generated when called.

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2843
File: holidays/countries/burundi.py:63-101
Timestamp: 2025-08-21T04:56:03.780Z
Learning: In the holidays library, countries with localization support consistently use tr() wrappers around holiday names when calling _add_* methods (e.g., self._add_new_years_day(tr("Holiday Name"))). This is the established pattern across United States, Thailand, and other l10n-enabled countries, contrary to any suggestion that translation is handled internally by _add_* methods.

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 3026
File: holidays/countries/spain.py:189-189
Timestamp: 2025-10-28T17:26:45.090Z
Learning: In the vacanza/holidays codebase, `_populate` methods (such as `_populate_public_holidays`, `_populate_subdiv_holidays`, and subdivision-specific methods like `_populate_subdiv_XX_public_holidays`) intentionally do not include return type annotations like `-> None`. This is a consistent pattern across country implementations (e.g., Germany, United States, Spain) and should not be changed even when static analysis tools like Ruff suggest adding them.
<!-- </add_learning>

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2642
File: holidays/countries/france.py:184-206
Timestamp: 2025-06-18T10:58:28.058Z
Learning: In the holidays library France implementation, creating shared private methods between subdivision-specific holiday population methods (like _populate_subdiv_57_public_holidays and _populate_subdiv_6ae_public_holidays) is not supported by the current framework architecture, so duplicate code between functionally identical subdivision methods should be left as-is.

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2642
File: holidays/countries/france.py:178-182
Timestamp: 2025-06-18T10:18:59.447Z
Learning: In the France holidays implementation, deprecated subdivision names like "Alsace-Moselle" and "Saint-Barthélémy" are handled through explicit conditionals in _populate_public_holidays() that map them to their corresponding new subdivision-specific holiday population methods, providing backward compatibility while users transition to the new ISO codes.

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2706
File: holidays/countries/cayman_islands.py:80-97
Timestamp: 2025-07-10T03:36:16.461Z
Learning: In the holidays library, date dictionaries that map years to specific dates (like queens_birthday_dates, special holiday dates, etc.) are typically defined within the _populate_public_holidays method rather than as module-level constants. This is the established library-wide pattern and should be maintained for consistency.

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2638
File: holidays/countries/svalbard_and_jan_mayen.py:26-32
Timestamp: 2025-06-16T11:46:35.303Z
Learning: When creating country holiday aliases that inherit from parent countries (like Svalbard and Jan Mayen from Norway, or Åland from Finland), it's standard practice to hardcode a specific subdivision code in the _populate methods since the subdivision codes for the parent country yield identical results. The Åland Islands implementation serves as the reference pattern for this approach.

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2706
File: holidays/countries/cayman_islands.py:80-97
Timestamp: 2025-07-10T03:36:16.461Z
Learning: In the holidays library, date dictionaries that map years to specific dates (like queens_birthday_dates, spring_bank_dates, thanksgiving_day_dates, etc.) are typically defined within the _populate_public_holidays method rather than as module-level constants. This is the established library-wide pattern seen across multiple country implementations including United Kingdom, United States, Sri Lanka, and others.

Learnt from: Wasif-Shahzad
Repo: vacanza/holidays PR: 2852
File: holidays/countries/tajikistan.py:55-56
Timestamp: 2025-08-24T06:53:35.897Z
Learning: In Tajikistan, March 8th is celebrated as Mother's Day (Рӯзи Модар) rather than International Women's Day, so the country-specific implementation should use _add_holiday_mar_8() rather than the shared _add_womens_day() helper from InternationalHolidays.

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2843
File: holidays/countries/burundi.py:63-101
Timestamp: 2025-08-21T04:56:03.780Z
Learning: In the holidays library, countries with localization support DO use tr() wrappers around holiday names when calling _add_* methods. This is the correct pattern for l10n-enabled country implementations, contrary to previous learning about translation being handled internally by _add_* methods.

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2942
File: holidays/countries/south_africa.py:91-98
Timestamp: 2025-09-18T07:01:12.236Z
Learning: In the holidays library South Africa implementation, inline ternary operators for holiday name selection (like "Republic Day" if self._year >= 1961 else "Union Day") are intentionally kept inline rather than extracted to separate variables, as this structure is designed in preparation for future localization (l10n) support where the contextual relationship between conditions and translatable strings needs to be preserved.

Learnt from: Wasif-Shahzad
Repo: vacanza/holidays PR: 2409
File: holidays/countries/qatar.py:27-46
Timestamp: 2025-04-03T16:58:27.175Z
Learning: In the holidays library, method names like `_add_holiday_2nd_tue_of_feb()` and `_add_holiday_1st_sun_of_mar()` use calendar constants like FEB, TUE, MAR, and SUN internally through parent class implementations even when these constants don't appear directly in the file.

Learnt from: KJhellico
Repo: vacanza/holidays PR: 2614
File: holidays/countries/guyana.py:146-179
Timestamp: 2025-06-14T20:12:37.212Z
Learning: The `_CustomHinduHolidays` mechanism works through `_CustomCalendarType` metaclass which renames public attributes (like `DIWALI_INDIA_DATES`) with a postfix, allowing `_HinduLunisolar::_get_holiday` to find and use custom holiday dates. When `_add_diwali_india()` is called, it uses the custom dates if available rather than calculated dates.