Add Palau holidays (#1776)

Co-authored-by: Arkadii Yakovets <ark@cho.red>
Co-authored-by: ~Jhellico <KJhellico@users.noreply.github.com>

README.rst

@@ -146,7 +146,7 @@ Available Countries
 .. _ISO 639-1 code: https://en.wikipedia.org/wiki/List_of_ISO_639-1_codes
 .. _ISO 639-2 code: https://en.wikipedia.org/wiki/List_of_ISO_639-2_codes
 
-We currently support 146 country codes. The standard way to refer to a country
+We currently support 147 country codes. The standard way to refer to a country
 is by using its `ISO 3166-1 alpha-2 code`_, the same used for domain names, and
 for a subdivision its `ISO 3166-2 code`_. Some countries have common or foreign
 names or abbreviations as aliases for their subdivisions. These are defined in
@@ -695,6 +695,11 @@ All other default values are highlighted with bold:
      -
      -
      -
+   * - Palau
+     - PW
+     -
+     -
+     - ARMED_FORCES, HALF_DAY
    * - Panama
      - PA
      -

holidays/countries/__init__.py

@@ -115,6 +115,7 @@
 from .northern_mariana_islands import NorthernMarianaIslands, MP, MNP, HolidaysMP
 from .norway import Norway, NO, NOR
 from .pakistan import Pakistan, PK, PAK
+from .palau import Palau, PW, PLW
 from .panama import Panama, PA, PAN
 from .papua_new_guinea import PapuaNewGuinea, PG, PNG
 from .paraguay import Paraguay, PY, PRY

holidays/countries/palau.py

@@ -0,0 +1,127 @@
+#  holidays
+#  --------
+#  A fast, efficient Python library for generating country, province and state
+#  specific sets of holidays on the fly. It aims to make determining whether a
+#  specific date is a holiday as fast and flexible as possible.
+#
+#  Authors: Vacanza Team and individual contributors (see AUTHORS file)
+#           dr-prodigy <dr.prodigy.github@gmail.com> (c) 2017-2023
+#           ryanss <ryanssdev@icloud.com> (c) 2014-2017
+#  Website: https://github.com/vacanza/python-holidays
+#  License: MIT (see LICENSE file)
+
+from holidays.calendars.gregorian import SEP, NOV
+from holidays.constants import ARMED_FORCES, HALF_DAY, PUBLIC
+from holidays.groups import ChristianHolidays, InternationalHolidays, StaticHolidays
+from holidays.observed_holiday_base import ObservedHolidayBase, SAT_TO_PREV_FRI, SUN_TO_NEXT_MON
+
+
+class Palau(ObservedHolidayBase, ChristianHolidays, InternationalHolidays):
+    """
+    References:
+    - http://www.paclii.org/pw/legis/consol_act/gpt1262/  # Chapter 7, Holidays.
+    - https://www.palaugov.pw/wp-content/uploads/2017/11/RPPL-No.-10-15-re.-Family-Day-Holiday.pdf
+    - https://www.facebook.com/PalauPresident/posts/195883107230463 # EO336 Memorial Day repealed
+    - https://www.taiwanembassy.org/pal_en/post/792.html # Earliest source for President's Day
+
+    If any of the holidays enumerated in section 701 of this chapter falls on Sunday, the
+    following Monday shall be observed as a holiday. If any of the holidays enumerated in
+    section 701 of this chapter falls on Saturday, the preceding Friday shall be observed
+    as a holiday.
+
+    As there's no record of President's Day (Jun 1) and Independence Day (Oct 1) being
+    legal holiday before 2017, as seen in RPRL 10-15, they shall be assumed to start in 2018
+    for our current implementation.
+    """
+
+    country = "PW"
+    supported_categories = (ARMED_FORCES, HALF_DAY, PUBLIC)
+    observed_label = "%s (observed)"
+
+    def __init__(self, *args, **kwargs):
+        ChristianHolidays.__init__(self)
+        InternationalHolidays.__init__(self)
+        StaticHolidays.__init__(self, PalauStaticHolidays)
+        kwargs.setdefault("observed_rule", SAT_TO_PREV_FRI + SUN_TO_NEXT_MON)
+        super().__init__(*args, **kwargs)
+
+    def _populate_public_holidays(self):
+        # Republic of Palau Public Law No. 2-15.
+        # The legislation was first adopted by the 2nd Olbiil Era Kelulau (1984-1988),
+        # but since we cannot find any info on its actual adoption date, we may as
+        # well use the formation date of the country as the placeholder cut-off date.
+        if self._year <= 1980:
+            return None
+
+        # Fixed Date Public Holidays.
+
+        # New Year's Day.
+        name = "New Year's Day"
+        self._add_observed(self._add_new_years_day(name))
+        self._add_observed(self._next_year_new_years_day, name=name, rule=SAT_TO_PREV_FRI)
+
+        # Youth Day.
+        self._add_observed(self._add_holiday_mar_15("Youth Day"))
+
+        # Senior Citizens Day.
+        self._add_observed(self._add_holiday_may_5("Senior Citizens Day"))
+
+        if self._year in {2011, 2012}:
+            # Memorial Day.
+            self._add_holiday_last_mon_of_may("Memorial Day")
+
+        if self._year >= 2018:
+            # President's Day.
+            self._add_observed(self._add_holiday_jun_1("President's Day"))
+
+        # Constitution Day.
+        self._add_observed(self._add_holiday_jul_9("Constitution Day"))
+
+        # Labor Day.
+        self._add_holiday_1st_mon_of_sep("Labor Day")
+
+        if self._year >= 2018:
+            # Independence Day.
+            self._add_observed(self._add_holiday_oct_1("Independence Day"))
+
+        # United Nations Day.
+        self._add_observed(self._add_united_nations_day("United Nations Day"))
+
+        # Thanksgiving Day.
+        self._add_holiday_4th_thu_of_nov("Thanksgiving Day")
+
+        if self._year >= 2017:
+            # Family Day.
+            self._add_holiday_4th_fri_of_nov("Family Day")
+
+        # Christmas Day.
+        self._add_observed(self._add_christmas_day("Christmas Day"))
+
+
+class PW(Palau):
+    pass
+
+
+class PLW(Palau):
+    pass
+
+
+class PalauStaticHolidays:
+    """
+    Sources:
+     - https://www.facebook.com/photo?fbid=1774513196034105&set=a.175933635892077
+     - https://www.facebook.com/photo/?fbid=1794692910682800&set=a.175933635892077
+     - https://www.facebook.com/photo/?fbid=1408133829338712&set=a.175933635892077
+    """
+
+    special_armed_forces_holidays = {
+        2020: (NOV, 11, "Veterans Day"),
+    }
+
+    special_half_day_holidays = {
+        2019: (SEP, 30, "Preparation for the 25th Independence Day of the Republic of Palau"),
+    }
+
+    special_public_holidays = {
+        2020: (NOV, 3, "National Day of Democracy"),
+    }

holidays/countries/south_korea.py

@@ -198,7 +198,7 @@ def add_three_day_holiday(dt: date, name: str):
 
         if 1950 <= self._year <= 1975:
             # United Nations Day.
-            self._add_holiday_oct_24(tr("국제연합일"))
+            self._add_united_nations_day(tr("국제연합일"))
 
         # Chuseok.
         name = tr("추석")

holidays/groups/international.py

@@ -194,3 +194,13 @@ def _add_world_war_two_victory_day(self, name):
         https://en.wikipedia.org/wiki/Victory_Day_(9_May)
         """
         return self._add_holiday_may_9(name)
+
+    def _add_united_nations_day(self, name):
+        """
+        Add United Nations Day (Oct 24th)
+
+        United Nations Day is an annual commemorative day, reflecting the
+        official creation of the United Nations on 24 October 1945.
+        https://en.wikipedia.org/wiki/United_Nations_Day
+        """
+        return self._add_holiday_oct_24(name)

holidays/registry.py

@@ -121,6 +121,7 @@
     "northern_mariana_islands": ("NorthernMarianaIslands", "MP", "MNP", "HolidaysMP"),
     "norway": ("Norway", "NO", "NOR"),
     "pakistan": ("Pakistan", "PK", "PAK"),
+    "palau": ("Palau", "PW", "PLW"),
     "panama": ("Panama", "PA", "PAN"),
     "papua_new_guinea": ("PapuaNewGuinea", "PG", "PNG"),
     "paraguay": ("Paraguay", "PY", "PRY"),