From d3ffbb8bc282a77bd6ae2be54a43d866ac167118 Mon Sep 17 00:00:00 2001
From: mishra-prince <88850888+mishra-prince@users.noreply.github.com>
Date: Mon, 28 Sep 2026 12:42:27 +0000
Subject: [PATCH 1/2] Make Timezone and FixedTimezone hashable

Both classes define __eq__ but not __hash__, which makes Python set
__hash__ to None and the instances unhashable (a regression since 3.1.0
when __eq__ was added). Restore hashability by defining __hash__
consistently with __eq__ on both classes.

Fixes #1008
---
 src/pendulum/tz/timezone.py |  6 ++++++
 tests/tz/test_timezone.py   | 12 ++++++++++++
 2 files changed, 18 insertions(+)

diff --git a/src/pendulum/tz/timezone.py b/src/pendulum/tz/timezone.py
index e46e13df1..6fcff5bde 100644
--- a/src/pendulum/tz/timezone.py
+++ b/src/pendulum/tz/timezone.py
@@ -69,6 +69,9 @@ def __new__(cls, key: str) -> Self:
     def __eq__(self, other: object) -> bool:
         return isinstance(other, Timezone) and self.key == other.key
 
+    def __hash__(self) -> int:
+        return hash((self.__class__, self.key))
+
     @property
     def name(self) -> str:
         return self.key
@@ -178,6 +181,9 @@ def __init__(self, offset: int, name: str | None = None) -> None:
     def __eq__(self, other: object) -> bool:
         return isinstance(other, FixedTimezone) and self._offset == other._offset
 
+    def __hash__(self) -> int:
+        return hash((self.__class__, self._offset))
+
     @property
     def name(self) -> str:
         return self._name
diff --git a/tests/tz/test_timezone.py b/tests/tz/test_timezone.py
index 3f0901681..cef378419 100644
--- a/tests/tz/test_timezone.py
+++ b/tests/tz/test_timezone.py
@@ -47,6 +47,18 @@ def test_equality():
     assert timezone("Europe/Paris") != timezone("Europe/Berlin")
 
 
+def test_hashable():
+    # Timezones are hashable and can be used as dict keys / set members.
+    # __eq__ and __hash__ must stay consistent: equal timezones hash equally.
+    assert hash(timezone("Europe/Paris")) == hash(timezone("Europe/Paris"))
+    assert timezone("Europe/Paris") in {timezone("Europe/Paris")}
+    assert len({timezone("Europe/Paris"), timezone("Europe/Berlin")}) == 2
+
+    assert hash(fixed_timezone(3600)) == hash(fixed_timezone(3600))
+    assert fixed_timezone(3600) in {fixed_timezone(3600)}
+    assert len({fixed_timezone(3600), fixed_timezone(7200)}) == 2
+
+
 def test_skipped_time_with_pre_rule():
     dt = datetime(2013, 3, 31, 2, 30, 45, 123456, fold=0)
     tz = timezone("Europe/Paris")

From 09853814711126a427c43cc3e52a46f1171a0e5d Mon Sep 17 00:00:00 2001
From: mishra-prince <88850888+mishra-prince@users.noreply.github.com>
Date: Mon, 28 Sep 2026 15:16:37 +0000
Subject: [PATCH 2/2] Hash only the equality value to preserve eq/hash
 invariant

__eq__ matches any Timezone/FixedTimezone with the same key/offset,
including subclasses, so the hash must not depend on the concrete class.
Hash the key (Timezone) and offset (FixedTimezone) directly.
---
 src/pendulum/tz/timezone.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/pendulum/tz/timezone.py b/src/pendulum/tz/timezone.py
index 6fcff5bde..ffc3c1304 100644
--- a/src/pendulum/tz/timezone.py
+++ b/src/pendulum/tz/timezone.py
@@ -70,7 +70,7 @@ def __eq__(self, other: object) -> bool:
         return isinstance(other, Timezone) and self.key == other.key
 
     def __hash__(self) -> int:
-        return hash((self.__class__, self.key))
+        return hash(self.key)
 
     @property
     def name(self) -> str:
@@ -182,7 +182,7 @@ def __eq__(self, other: object) -> bool:
         return isinstance(other, FixedTimezone) and self._offset == other._offset
 
     def __hash__(self) -> int:
-        return hash((self.__class__, self._offset))
+        return hash(self._offset)
 
     @property
     def name(self) -> str: