Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2881
File: holidays/countries/chile.py:121-123
Timestamp: 2025-09-14T04:36:25.108Z
Learning: In the Chile holidays implementation, the MON_ONLY observance rule is used correctly for January 2 holiday. The rule means "only add this observed holiday if the original date falls on Monday", which perfectly handles Law 20.983's requirement that January 2 is only a holiday when January 1 falls on Sunday, since January 2 falls on Monday exactly when January 1 falls on Sunday.

Learnt from: mbfarah
Repo: vacanza/holidays PR: 2798
File: holidays/countries/chile.py:278-281
Timestamp: 2025-08-12T03:21:09.116Z
Learning: In Chile holidays implementation, the general rule for September 17 (years >= 2007) uses MON_ONLY for years 2007-2016, meaning it only adds the holiday when September 17 falls on a Monday. For years when September 17 falls on other days and was declared a one-off holiday by specific laws, it must be added to the special_public_holidays dictionary.

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: 2881
File: holidays/countries/south_africa.py:69-75
Timestamp: 2025-09-14T07:26:25.431Z
Learning: When reviewing historical holiday implementations in the vacanza/holidays repository, trust the maintainers' research and implementation decisions for specific historical edge cases, especially when they can provide sources like Wikipedia or other historical documentation that supports unusual or complex date calculation rules during specific time periods.

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2881
File: holidays/countries/chile.py:121-123
Timestamp: 2025-09-14T04:36:25.108Z
Learning: In the Chile holidays implementation, the MON_ONLY observance rule correctly implements Law 20.983 for January 2. MON_ONLY is defined as ObservedRule({TUE: None, WED: None, THU: None, FRI: None, SAT: None, SUN: None}), which means when _add_observed() is called with MON_ONLY, it removes holidays that fall on Tuesday through Sunday (via self.pop(dt)) and only keeps holidays that fall on Monday. This perfectly implements the law that January 2 is only a holiday when January 1 falls on Sunday.

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: mbfarah
Repo: vacanza/holidays PR: 2798
File: holidays/countries/chile.py:278-281
Timestamp: 2025-08-12T03:21:09.116Z
Learning: September 17, 2010 and September 20, 2010 were both one-off holidays in Chile established by Law 20.450, separate from the general September 17 observance rule that only applies to Mondays.

Learnt from: KJhellico
Repo: vacanza/holidays PR: 2608
File: tests/countries/test_saint_vincent_and_the_grenadines.py:162-178
Timestamp: 2025-07-02T18:17:53.342Z
Learning: In the Saint Vincent and the Grenadines holidays implementation, New Year's Day is added without observed rules using `_add_new_years_day()` and should not include observed rule testing in its test method. Only holidays explicitly wrapped with `_add_observed()` have observed 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: KJhellico
Repo: vacanza/holidays PR: 3111
File: holidays/financial/ny_stock_exchange.py:63-65
Timestamp: 2025-12-07T18:09:57.513Z
Learning: In the NYSE holidays implementation (holidays/financial/ny_stock_exchange.py), the _add_observed method unconditionally overrides kwargs["rule"] based on the date's year because _move_holiday calls _add_observed with rule=None, and this None value needs to be replaced with the appropriate year-based rule (SUN_TO_NEXT_MON for years <= 1952, otherwise the class's observed_rule).

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2881
File: tests/countries/test_curacao.py:29-29
Timestamp: 2025-09-20T12:24:28.864Z
Learning: For Curacao in the holidays library, PUBLIC and HALF_DAY categories have different start years - PUBLIC holidays begin at the country's start_year while HALF_DAY holidays begin in 2010. When testing no_holidays methods, each category should be tested separately with appropriate pre-start years rather than using a unified supported_categories approach.

Learnt from: mbfarah
Repo: vacanza/holidays PR: 2798
File: holidays/countries/chile.py:278-281
Timestamp: 2025-08-12T03:21:09.116Z
Learning: In Chile holidays implementation, the general rule for September 17 (years >= 2007) uses MON_ONLY for years 2007-2016, meaning it only adds the holiday when September 17 falls on a Monday. For years when September 17 falls on other days and was declared a one-off holiday by specific laws, it must be added to the special_public_holidays dictionary.

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2881
File: holidays/countries/chile.py:121-123
Timestamp: 2025-09-14T04:36:25.108Z
Learning: In the Chile holidays implementation, the MON_ONLY observance rule is used correctly for January 2 holiday. The rule means "only add this observed holiday if the original date falls on Monday", which perfectly handles Law 20.983's requirement that January 2 is only a holiday when January 1 falls on Sunday, since January 2 falls on Monday exactly when January 1 falls on Sunday.

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2881
File: holidays/countries/chile.py:121-123
Timestamp: 2025-09-14T04:36:25.108Z
Learning: In the Chile holidays implementation, the MON_ONLY observance rule correctly implements Law 20.983 for January 2. MON_ONLY is defined as ObservedRule({TUE: None, WED: None, THU: None, FRI: None, SAT: None, SUN: None}), which means when _add_observed() is called with MON_ONLY, it removes holidays that fall on Tuesday through Sunday (via self.pop(dt)) and only keeps holidays that fall on Monday. This perfectly implements the law that January 2 is only a holiday when January 1 falls on Sunday.

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: 2833
File: holidays/countries/uganda.py:50-56
Timestamp: 2025-08-25T09:57:22.291Z
Learning: In the holidays package, when adding comments for year-restricted holidays in Uganda and similar country modules, include specific legal or historical context such as the actual laws, parliamentary acts, or government decisions that established the holidays, rather than just generic "since YEAR" information. For example, reference the specific Parliament act, decree, or historical event that created the holiday.

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: 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: 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: mbfarah
Repo: vacanza/holidays PR: 2798
File: holidays/countries/chile.py:278-281
Timestamp: 2025-08-12T03:21:09.116Z
Learning: September 17, 2010 and September 20, 2010 were both one-off holidays in Chile established by Law 20.450, separate from the general September 17 observance rule that only applies to Mondays.

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: 2439
File: holidays/calendars/thai.py:0-0
Timestamp: 2025-04-06T17:44:24.598Z
Learning: When making code suggestions, only include the specific lines that need to be changed in the committable suggestion part, without surrounding unrelated code.

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2881
File: tests/countries/test_argentina.py:228-229
Timestamp: 2025-11-08T04:56:18.070Z
Learning: Argentina: Good Friday ("Viernes Santo") is established from 1977 by Law 21329. In tests/countries/test_argentina.py, assert presence for range(1977, self.end_year) and absence for range(self.start_year, 1977); do not assert over self.full_range.

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: 2831
File: holidays/countries/south_sudan.py:21-30
Timestamp: 2025-08-25T10:51:08.068Z
Learning: In the holidays library, references in country/market holiday implementations should be ordered as follows: Wikipedia links for the country/market holidays first, then country-specific official sources for newer implementations, then Wikipedia links for each individual non-standard holiday if any are required. Official government sources should not be placed first ahead of Wikipedia links.

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: 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: 2354
File: holidays/countries/fiji.py:146-159
Timestamp: 2025-03-19T16:54:58.657Z
Learning: In the holidays library implementation, explicit holiday dates (like Diwali in Fiji) are only defined for historical years with official sources (2016-2025). Future dates beyond the explicitly defined range are automatically calculated by methods like `_add_diwali`, which provide approximations when official dates aren't yet available.

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_iran.py:28-28
Timestamp: 2025-09-14T16:05:55.205Z
Learning: In tests/countries/test_iran.py, using years=(self.start_year - 1, 2102) in the no-holiday test is intentional because Iran uses the Persian Calendar which has specific supported year range constraints, and 2102 represents the upper limit of the Persian Calendar's supported range, not just an arbitrary far-future date.

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: 2398
File: holidays/countries/guinea.py:73-77
Timestamp: 2025-04-03T12:36:41.201Z
Learning: In the Holidays library, comments explaining year restrictions for holidays should be placed above the year check conditional statement, not inside it. Example format:
```python
# reason why goes here
if start_year <= self._year <= end_year:
    # Holiday name
    self._add_holiday_function(tr("Holiday Name"))
```

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2881
File: tests/countries/test_barbados.py:21-23
Timestamp: 2025-09-14T16:03:13.558Z
Learning: In tests/countries/test_barbados.py, using years_non_observed=range(2000, 2024) is intentional because all observed holiday examples fall within 2001-2023, making this range appropriate for limiting testing to years where observed holidays actually exist in the test data.

Learnt from: PPsyrius
Repo: vacanza/holidays PR: 2881
File: tests/countries/test_argentina.py:375-375
Timestamp: 2025-09-03T16:49:35.246Z
Learning: In the holidays library, national holiday tests use self.full_range (or similar comprehensive year ranges) even when explicit test dates only show modern observance. This is intentional for correctness and comprehensive coverage, unlike subdivision-specific holidays which have explicit year boundaries based on known start dates.

Learnt from: KJhellico
Repo: vacanza/holidays PR: 3135
File: holidays/countries/united_states.py:1175-1178
Timestamp: 2025-12-15T22:50:33.654Z
Learning: In the holidays library (vacanza/holidays), for Puerto Rico and potentially other US territories, maintain the documented separation: place Spanish holiday name comments on one line, followed by a blank line, and then the English localization comment. Do not remove the blank line separator, as it documents the Spanish name (e.g., 'Día de la Abolición de la Esclavitud') while the English name below (e.g., 'Emancipation Day') is the actual localization.