vacanza · arkid15r · Aug 14, 2025 · Aug 11, 2025 · Aug 11, 2025 · Aug 11, 2025
@@ -0,0 +1,31 @@
+#  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 CONTRIBUTORS file)
+#           dr-prodigy <dr.prodigy.github@gmail.com> (c) 2017-2023
+#           ryanss <ryanssdev@icloud.com> (c) 2014-2017
+#  Website: https://github.com/vacanza/holidays
+#  License: MIT (see LICENSE file)
+
+ETHIOPIAN_CALENDAR = "ETHIOPIAN_CALENDAR"
+
+
+def is_ethiopian_leap_year(year: int) -> bool:
+    """Determine if the Ethiopian year that starts in the given Gregorian year is a leap year.
+
+    Ethiopian leap years follow the Coptic/Julian rule:
+        * Every 4 years without exception (no century rule).
+        * The Ethiopian year starts on September 11 (or 12 in an Ethiopian leap year).
+
+    Args:
+        year:
+            Gregorian year to evaluate.
+
+    Returns:
+        `True` if an Ethiopian leap year starts in the given Gregorian year, `False` otherwise.
+    """
+
+    return (year + 1) % 4 == 0
@@ -11,3 +11,17 @@
 #  License: MIT (see LICENSE file)
 
 JULIAN_CALENDAR = "JULIAN_CALENDAR"
+
+
+def julian_calendar_drift(year: int) -> int:
+    """Return the Julian–Gregorian date drift relative to the 1899–2099 baseline.
+
+    Args:
+        year:
+            Gregorian year to check.
+
+    Returns:
+        Number of days to add/subtract relative to the 1899–2099 baseline.
+    """
+
+    return -13 if year <= 1582 else (year // 100) - (year // 400) - 15
@@ -10,12 +10,11 @@
 #  Website: https://github.com/vacanza/holidays
 #  License: MIT (see LICENSE file)
 
-from calendar import isleap
 from gettext import gettext as tr
 
 from holidays.calendars import _CustomIslamicHolidays
-from holidays.calendars.gregorian import JAN, AUG, SEP, NOV
-from holidays.calendars.julian import JULIAN_CALENDAR
+from holidays.calendars.ethiopian import ETHIOPIAN_CALENDAR, is_ethiopian_leap_year
+from holidays.calendars.gregorian import AUG, SEP, NOV
 from holidays.constants import PUBLIC, WORKDAY
 from holidays.groups import ChristianHolidays, InternationalHolidays, IslamicHolidays
 from holidays.holiday_base import HolidayBase
@@ -30,7 +29,7 @@ class Ethiopia(HolidayBase, ChristianHolidays, InternationalHolidays, IslamicHol
         * <https://web.archive.org/web/20250427173714/https://www.edarabia.com/ethiopia/public-holidays/>
         * <https://en.wikipedia.org/wiki/Public_holidays_in_Ethiopia>
         * <https://en.wikipedia.org/wiki/Nations,_Nationalities_and_Peoples'_Day>
-        * <https://web.archive.org/web/20250408213218/https://www.timeanddate.com/holidays/ethiopia/>
+        * <https://web.archive.org/web/20250811041201/https://www.timeanddate.com/holidays/ethiopia/2025>
     """
 
     country = "ET"
@@ -42,30 +41,14 @@ class Ethiopia(HolidayBase, ChristianHolidays, InternationalHolidays, IslamicHol
     supported_categories = (PUBLIC, WORKDAY)
     supported_languages = ("am", "ar", "en_ET", "en_US")
 
-    def _is_leap_year(self) -> bool:
-        """Determine if the Ethiopian calendar year is a leap year.
-
-        Ethiopian leap years generally align with Gregorian leap years until
-        February 2100. However, the Ethiopian calendar starts earlier (on September 11),
-        which affects holidays between September 11 and January 1.
-
-        To account for this shift, the method checks whether next year is a leap year
-        in the Gregorian calendar.
-
-        Returns:
-            `True` if the Ethiopian year is a leap year, `False` otherwise.
-        """
-
-        return isleap(self._year + 1)
-
     def __init__(self, *args, islamic_show_estimated: bool = True, **kwargs):
         """
         Args:
             islamic_show_estimated:
                 Whether to add "estimated" label to Islamic holidays name
                 if holiday date is estimated.
         """
-        ChristianHolidays.__init__(self, JULIAN_CALENDAR)
+        ChristianHolidays.__init__(self, ETHIOPIAN_CALENDAR)
         InternationalHolidays.__init__(self)
         IslamicHolidays.__init__(
             self, cls=EthiopiaIslamicHolidays, show_estimated=islamic_show_estimated
@@ -77,7 +60,7 @@ def _populate_public_holidays(self):
         self._add_christmas_day(tr("የገና ወይም የልደት በዓል"))
 
         # Epiphany.
-        self._add_holiday(tr("የጥምቀት በዓል"), JAN, 20 if super()._is_leap_year() else 19)
+        self._add_epiphany_day(tr("የጥምቀት በዓል"))
 
         if self._year >= 1996:
             # Adwa Victory Day.
@@ -100,14 +83,19 @@ def _populate_public_holidays(self):
             self._add_holiday_may_28(tr("ደርግ የወደቀበት ቀን"))
 
         # Ethiopian New Year.
-        self._add_holiday(tr("የዘመን መለወጫ (እንቁጣጣሽ) በዓል"), SEP, 12 if self._is_leap_year() else 11)
+        self._add_ethiopian_new_year(tr("የዘመን መለወጫ (እንቁጣጣሽ) በዓል"))
 
         # Finding of True Cross.
-        self._add_holiday(tr("የመስቀል በዓል"), SEP, 28 if self._is_leap_year() else 27)
+        self._add_finding_of_true_cross(tr("የመስቀል በዓል"))
 
         if self._year <= 1990:
-            # Popular Revolution Commemoration Day.
-            self._add_holiday(tr("የአብዮት ቀን"), SEP, 13 if self._is_leap_year() else 12)
+            # Julian Date Drift shouldn't affect this one.
+            self._add_holiday(
+                # Popular Revolution Commemoration Day.
+                tr("የአብዮት ቀን"),
+                SEP,
+                13 if is_ethiopian_leap_year(self._year) else 12,
+            )
 
             # October Revolution Day.
             self._add_holiday_nov_7(tr("የጥቅምት አብዮት ቀን"))
@@ -139,15 +127,16 @@ class ETH(Ethiopia):
 
 
 class EthiopiaIslamicHolidays(_CustomIslamicHolidays):
-    EID_AL_ADHA_DATES_CONFIRMED_YEARS = (2018, 2024)
+    EID_AL_ADHA_DATES_CONFIRMED_YEARS = (2018, 2025)
     EID_AL_ADHA_DATES = {
         2018: (AUG, 22),
     }
 
     EID_AL_FITR_DATES_CONFIRMED_YEARS = (2018, 2025)
 
-    MAWLID_DATES_CONFIRMED_YEARS = (2018, 2024)
+    MAWLID_DATES_CONFIRMED_YEARS = (2018, 2025)
     MAWLID_DATES = {
         2018: (NOV, 21),
         2019: (NOV, 10),
+        2025: (SEP, 5),
     }
@@ -14,8 +14,9 @@
 
 from dateutil.easter import EASTER_ORTHODOX, EASTER_WESTERN, easter
 
-from holidays.calendars.gregorian import GREGORIAN_CALENDAR, JAN, DEC, _timedelta
-from holidays.calendars.julian import JULIAN_CALENDAR
+from holidays.calendars.ethiopian import ETHIOPIAN_CALENDAR, is_ethiopian_leap_year
+from holidays.calendars.gregorian import GREGORIAN_CALENDAR, JAN, AUG, SEP, DEC, _timedelta
+from holidays.calendars.julian import JULIAN_CALENDAR, julian_calendar_drift
 from holidays.calendars.julian_revised import JULIAN_REVISED_CALENDAR
 
 
@@ -36,8 +37,8 @@ def __get_christmas_day(self, calendar=None):
         self.__verify_calendar(calendar)
 
         return (
-            date(self._year, JAN, 7)
-            if self.__is_julian_calendar(calendar)
+            _timedelta(date(self._year, JAN, 7), julian_calendar_drift(self._year - 1))
+            if self.__is_julian_calendar(calendar) or self.__is_ethiopian_calendar(calendar)
             else date(self._year, DEC, 25)
         )
 
@@ -53,6 +54,14 @@ def __get_easter_sunday(self, calendar=None):
             method=EASTER_WESTERN if self.__is_gregorian_calendar(calendar) else EASTER_ORTHODOX,
         )
 
+    @staticmethod
+    def __is_ethiopian_calendar(calendar):
+        """
+        Return True if `calendar` is Ethiopian calendar.
+        Return False otherwise.
+        """
+        return calendar == ETHIOPIAN_CALENDAR
+
     @staticmethod
     def __is_gregorian_calendar(calendar):
         """
@@ -74,10 +83,15 @@ def __verify_calendar(calendar):
         """
         Verify calendar type.
         """
-        if calendar not in {GREGORIAN_CALENDAR, JULIAN_CALENDAR, JULIAN_REVISED_CALENDAR}:
+        if calendar not in {
+            ETHIOPIAN_CALENDAR,
+            GREGORIAN_CALENDAR,
+            JULIAN_CALENDAR,
+            JULIAN_REVISED_CALENDAR,
+        }:
             raise ValueError(
-                f"Unknown calendar name: {calendar}. "
-                f"Use `{GREGORIAN_CALENDAR}`, `{JULIAN_CALENDAR}` or `{JULIAN_REVISED_CALENDAR}`."
+                f"Unknown calendar name: {calendar}. Use `{ETHIOPIAN_CALENDAR}`, "
+                f"`{GREGORIAN_CALENDAR}`, `{JULIAN_CALENDAR}` or `{JULIAN_REVISED_CALENDAR}`."
             )
 
     @property
@@ -158,7 +172,9 @@ def _add_assumption_of_mary_day(self, name, calendar=None) -> date:
         self.__verify_calendar(calendar)
 
         return (
-            self._add_holiday_aug_28(name)
+            self._add_holiday(
+                name, _timedelta(date(self._year, AUG, 28), julian_calendar_drift(self._year))
+            )
             if self.__is_julian_calendar(calendar)
             else self._add_holiday_aug_15(name)
         )
@@ -299,10 +315,30 @@ def _add_epiphany_day(self, name, calendar=None) -> date:
         calendar = calendar or self.__calendar
         self.__verify_calendar(calendar)
 
-        return (
-            self._add_holiday_jan_19(name)
-            if self.__is_julian_calendar(calendar)
-            else self._add_holiday_jan_6(name)
+        if self.__is_julian_calendar(calendar) or self.__is_ethiopian_calendar(calendar):
+            dt = _timedelta(date(self._year, JAN, 19), julian_calendar_drift(self._year - 1))
+            return self._add_holiday(
+                name,
+                _timedelta(dt, +1)
+                if self.__is_ethiopian_calendar(calendar)
+                and is_ethiopian_leap_year(self._year - 1)
+                else dt,
+            )
+        else:
+            return self._add_holiday_jan_6(name)
+
+    def _add_finding_of_true_cross(self, name) -> date:
+        """
+        Add Finding of True Cross.
+
+        Finding of True Cross, also known as Meskel, is an Ethiopian and Eritrean Orthodox
+        Tewahedo Church holiday that commemorates the discovery of the True Cross by the
+        Roman Empress Saint Helena of Constantinople in the fourth century.
+        https://en.wikipedia.org/wiki/Meskel
+        """
+        dt = _timedelta(date(self._year, SEP, 27), julian_calendar_drift(self._year))
+        return self._add_holiday(
+            name, _timedelta(dt, +1) if is_ethiopian_leap_year(self._year) else dt
         )
 
     def _add_good_friday(self, name, calendar=None) -> date:

@@ -12,7 +12,9 @@
 
 from datetime import date
 
-from holidays.calendars.gregorian import JAN
+from holidays.calendars.ethiopian import is_ethiopian_leap_year
+from holidays.calendars.gregorian import JAN, SEP, _timedelta
+from holidays.calendars.julian import julian_calendar_drift
 
 
 class InternationalHolidays:
@@ -85,6 +87,20 @@ def _add_columbus_day(self, name):
         """
         return self._add_holiday_oct_12(name)
 
+    def _add_ethiopian_new_year(self, name) -> date:
+        """
+        Add Ethiopian New Year.
+
+        Ethiopian New Year, also known as Enkutatash, is a public holiday celebrated
+        on Meskerem 1 in the Ethiopian calendar, marking the start of the year in
+        Ethiopia and Eritrea.
+        https://en.wikipedia.org/wiki/Enkutatash
+        """
+        dt = _timedelta(date(self._year, SEP, 11), julian_calendar_drift(self._year))
+        return self._add_holiday(
+            name, _timedelta(dt, +1) if is_ethiopian_leap_year(self._year) else dt
+        )
+
     def _add_europe_day(self, name):
         """
         Add Europe Day (May 9th)

@@ -702,8 +702,8 @@
     "2025-05-01": "International Workers' Day",
     "2025-05-05": "Ethiopian Patriots' Victory Day",
     "2025-05-28": "Downfall of the Dergue Regime Day",
-    "2025-06-06": "Eid al-Adha (estimated)",
-    "2025-09-04": "Prophet's Birthday (estimated)",
+    "2025-06-06": "Eid al-Adha",
+    "2025-09-05": "Prophet's Birthday",
     "2025-09-11": "Ethiopian New Year",
     "2025-09-27": "Finding of True Cross",
     "2025-12-09": "Nations, Nationalities and Peoples Day",

@@ -0,0 +1,37 @@
+#  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 CONTRIBUTORS file)
+#           dr-prodigy <dr.prodigy.github@gmail.com> (c) 2017-2023
+#           ryanss <ryanssdev@icloud.com> (c) 2014-2017
+#  Website: https://github.com/vacanza/holidays
+#  License: MIT (see LICENSE file)
+
+import unittest
+
+from holidays.calendars.ethiopian import is_ethiopian_leap_year
+
+
+class TestEthiopianCalendar(unittest.TestCase):
+    def test_is_ethiopian_leap_year(self):
+        known_ethiopian_leap_years = {
+            # Known Cases.
+            2022: False,
+            2023: True,
+            2024: False,
+            2025: False,
+            # Future Cases.
+            2098: False,
+            2099: True,
+            2100: False,
+            2101: False,
+            2198: False,
+            2199: True,
+            2200: False,
+            2201: False,
+        }
+        for year in known_ethiopian_leap_years:
+            self.assertEqual(known_ethiopian_leap_years[year], is_ethiopian_leap_year(year))
@@ -0,0 +1,36 @@
+#  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 CONTRIBUTORS file)
+#           dr-prodigy <dr.prodigy.github@gmail.com> (c) 2017-2023
+#           ryanss <ryanssdev@icloud.com> (c) 2014-2017
+#  Website: https://github.com/vacanza/holidays
+#  License: MIT (see LICENSE file)
+
+import unittest
+
+from holidays.calendars.julian import julian_calendar_drift
+
+
+class TestJulianCalendar(unittest.TestCase):
+    def test_julian_calendar_drift(self):
+        known_julian_calendar_drift = {
+            1400: -13,
+            1500: -13,
+            1581: -13,
+            1582: -13,
+            1583: -3,
+            1600: -3,
+            1700: -2,
+            1800: -1,
+            1900: 0,
+            2000: 0,
+            2025: 0,
+            2100: +1,
+            2200: +2,
+        }
+        for year in known_julian_calendar_drift:
+            self.assertEqual(known_julian_calendar_drift[year], julian_calendar_drift(year))