python-pendulum · parinporecha · Apr 19, 2026 · Apr 20, 2026 · Apr 20, 2026
diff --git a/src/pendulum/__init__.py b/src/pendulum/__init__.py
@@ -286,7 +286,11 @@ def from_timestamp(timestamp: int | float, tz: str | Timezone = UTC) -> DateTime
     """
     Create a DateTime instance from a timestamp.
     """
-    dt = _datetime.datetime.fromtimestamp(timestamp, tz=UTC)
+    try:
+        dt = _datetime.datetime.fromtimestamp(timestamp, tz=UTC)
+    except (OSError, OverflowError):
+        epoch = _datetime.datetime(1970, 1, 1, tzinfo=UTC)
+        dt = epoch + _datetime.timedelta(seconds=timestamp)
 
     dt = datetime(
         dt.year, dt.month, dt.day, dt.hour, dt.minute, dt.second, dt.microsecond

diff --git a/src/pendulum/datetime.py b/src/pendulum/datetime.py
@@ -1253,11 +1253,23 @@ def __radd__(self, other: datetime.timedelta) -> Self:
     def fromtimestamp(cls, t: float, tz: datetime.tzinfo | None = None) -> Self:
         tzinfo = pendulum._safe_timezone(tz)
 
-        return cls.instance(datetime.datetime.fromtimestamp(t, tz=tzinfo), tz=tzinfo)
+        try:
+            dt = datetime.datetime.fromtimestamp(t, tz=tzinfo)
+        except (OSError, OverflowError):
+            dt = (cls._EPOCH + datetime.timedelta(seconds=t)).astimezone(tzinfo)
+
+        return cls.instance(dt, tz=tzinfo)
 
     @classmethod
     def utcfromtimestamp(cls, t: float) -> Self:
-        return cls.instance(datetime.datetime.utcfromtimestamp(t), tz=None)
+        try:
+            dt = datetime.datetime.utcfromtimestamp(t)
+        except (OSError, OverflowError):
+            # Match datetime.datetime.utcfromtimestamp(), which returns a
+            # naive datetime representing UTC.
+            dt = datetime.datetime(1970, 1, 1) + datetime.timedelta(seconds=t)
+
+        return cls.instance(dt, tz=None)
 
     @classmethod
     def fromordinal(cls, n: int) -> Self:

diff --git a/tests/datetime/test_behavior.py b/tests/datetime/test_behavior.py
@@ -1,8 +1,13 @@
 from __future__ import annotations
 
+import datetime as datetime_
+import importlib
 import pickle
+import types
 import zoneinfo
 
+import pytest
+
 from copy import deepcopy
 from datetime import date
 from datetime import datetime
@@ -107,6 +112,54 @@ def test_utcfromtimestamp():
     assert p == dt
 
 
+@pytest.mark.parametrize("exception_type", [OSError, OverflowError])
+def test_fromtimestamp_falls_back_for_negative_timestamp(monkeypatch, exception_type):
+    pendulum_datetime_module = importlib.import_module("pendulum.datetime")
+
+    class FakeDateTime(datetime_.datetime):
+        @classmethod
+        def fromtimestamp(cls, t: float, tz: datetime_.tzinfo | None = None):
+            if t == -43201:
+                raise exception_type("Invalid argument")
+
+            return super().fromtimestamp(t, tz=tz)
+
+    monkeypatch.setattr(
+        pendulum_datetime_module,
+        "datetime",
+        types.SimpleNamespace(datetime=FakeDateTime, timedelta=datetime_.timedelta),
+    )
+
+    p = pendulum.DateTime.fromtimestamp(-43201, pendulum.UTC)
+
+    assert p == pendulum.datetime(1969, 12, 31, 11, 59, 59)
+    assert p.timezone_name == "UTC"
+
+
+@pytest.mark.parametrize("exception_type", [OSError, OverflowError])
+def test_utcfromtimestamp_falls_back_for_negative_timestamp(monkeypatch, exception_type):
+    pendulum_datetime_module = importlib.import_module("pendulum.datetime")
+
+    class FakeDateTime(datetime_.datetime):
+        @classmethod
+        def utcfromtimestamp(cls, t: float):
+            if t == -43201:
+                raise exception_type("Invalid argument")
+
+            return super().utcfromtimestamp(t)
+
+    monkeypatch.setattr(
+        pendulum_datetime_module,
+        "datetime",
+        types.SimpleNamespace(datetime=FakeDateTime, timedelta=datetime_.timedelta),
+    )
+
+    p = pendulum.DateTime.utcfromtimestamp(-43201)
+
+    assert p == pendulum.naive(1969, 12, 31, 11, 59, 59)
+    assert p.tzinfo is None
+
+
 def test_fromordinal():
     assert datetime.fromordinal(730120) == pendulum.DateTime.fromordinal(730120)
 

diff --git a/tests/datetime/test_create_from_timestamp.py b/tests/datetime/test_create_from_timestamp.py
@@ -1,6 +1,9 @@
 from __future__ import annotations
 
+import datetime as datetime_
+
 import pendulum
+import pytest
 
 from pendulum import timezone
 from tests.conftest import assert_datetime
@@ -22,3 +25,41 @@ def test_create_from_timestamp_with_timezone():
     d = pendulum.from_timestamp(0, timezone("America/Toronto"))
     assert d.timezone_name == "America/Toronto"
     assert_datetime(d, 1969, 12, 31, 19, 0, 0)
+
+
+def test_create_from_timestamp_negative():
+    d = pendulum.from_timestamp(-43201)
+    assert_datetime(d, 1969, 12, 31, 11, 59, 59)
+    assert d.timezone_name == "UTC"
+
+
+def test_create_from_timestamp_negative_with_timezone():
+    d = pendulum.from_timestamp(-43201, "America/Toronto")
+    assert d.timezone_name == "America/Toronto"
+    assert_datetime(d, 1969, 12, 31, 6, 59, 59)
+
+
+def test_create_from_timestamp_negative_with_microseconds():
+    d = pendulum.from_timestamp(-43201.5)
+    assert_datetime(d, 1969, 12, 31, 11, 59, 58, 500000)
+    assert d.timezone_name == "UTC"
+
+
+@pytest.mark.parametrize("exception_type", [OSError, OverflowError])
+def test_create_from_timestamp_falls_back_for_negative_timestamp(
+    monkeypatch, exception_type
+):
+    class FakeDateTime(datetime_.datetime):
+        @classmethod
+        def fromtimestamp(cls, timestamp: float, tz: datetime_.tzinfo | None = None):
+            if timestamp == -43201:
+                raise exception_type("Invalid argument")
+
+            return super().fromtimestamp(timestamp, tz=tz)
+
+    monkeypatch.setattr(pendulum._datetime, "datetime", FakeDateTime)
+
+    d = pendulum.from_timestamp(-43201)
+
+    assert_datetime(d, 1969, 12, 31, 11, 59, 59)
+    assert d.timezone_name == "UTC"