Fix incorrect DateTime ordering during DST fold transitions

Dockerfile

@@ -0,0 +1,12 @@
+FROM public.ecr.aws/d3j8x8q7/olympus-base-python:latest
+
+WORKDIR /app
+
+# Copy repository into the image before installing
+COPY . .
+
+# Use pip to install in editable mode with test extras to avoid Poetry issues
+RUN python -m pip install --upgrade pip
+RUN python -m pip install -e ".[test]"
+
+CMD ["/bin/bash"]

src/pendulum/datetime.py

@@ -554,6 +554,48 @@ def is_anniversary(  # type: ignore[override]
 
         return (self.month, self.day) == (instance.month, instance.day)
 
+    # Rich ordering operations
+    def __lt__(self, other: datetime.datetime) -> bool:  # type: ignore[override]
+        if not isinstance(other, datetime.datetime):
+            return NotImplemented
+
+        # Normalize both operands to UTC stdlib datetimes using base implementation
+        self_utc = datetime.datetime.astimezone(self, UTC)
+        other_dt = other if isinstance(other, DateTime) else DateTime.instance(other)
+        other_utc = datetime.datetime.astimezone(other_dt, UTC)
+
+        return datetime.datetime.__lt__(self_utc, other_utc)
+
+    def __le__(self, other: datetime.datetime) -> bool:  # type: ignore[override]
+        if not isinstance(other, datetime.datetime):
+            return NotImplemented
+
+        self_utc = datetime.datetime.astimezone(self, UTC)
+        other_dt = other if isinstance(other, DateTime) else DateTime.instance(other)
+        other_utc = datetime.datetime.astimezone(other_dt, UTC)
+
+        return datetime.datetime.__le__(self_utc, other_utc)
+
+    def __gt__(self, other: datetime.datetime) -> bool:  # type: ignore[override]
+        if not isinstance(other, datetime.datetime):
+            return NotImplemented
+
+        self_utc = datetime.datetime.astimezone(self, UTC)
+        other_dt = other if isinstance(other, DateTime) else DateTime.instance(other)
+        other_utc = datetime.datetime.astimezone(other_dt, UTC)
+
+        return datetime.datetime.__gt__(self_utc, other_utc)
+
+    def __ge__(self, other: datetime.datetime) -> bool:  # type: ignore[override]
+        if not isinstance(other, datetime.datetime):
+            return NotImplemented
+
+        self_utc = datetime.datetime.astimezone(self, UTC)
+        other_dt = other if isinstance(other, DateTime) else DateTime.instance(other)
+        other_utc = datetime.datetime.astimezone(other_dt, UTC)
+
+        return datetime.datetime.__ge__(self_utc, other_utc)
+
     # ADDITIONS AND SUBSTRACTIONS
 
     def add(

test.sh

@@ -0,0 +1,24 @@
+#!/bin/sh
+set -eu
+
+if [ "$#" -ne 1 ]; then
+    echo "Usage: $0 {base|new}"
+    exit 1
+fi
+
+case "$1" in
+base)
+    # Run the comparison file but exclude the new regression test that
+    # doesn't exist in the base commit.
+    poetry run pytest -q tests/datetime/test_comparison.py -k "not less_than_with_fold"
+    ;;
+new)
+    # Run the full file including the new regression test.
+    poetry run pytest -q tests/datetime/test_comparison.py
+    ;;
+*)
+    echo "Usage: $0 {base|new}"
+    exit 1
+    ;;
+esac
+

tests/datetime/test_comparison.py

@@ -392,3 +392,35 @@ def test_comparison_to_unsupported():
 
     assert dt1 != "test"
     assert dt1 not in ["test"]
+
+
+def test_less_than_with_fold():
+    d1 = pendulum.datetime(
+        2023,
+        11,
+        5,
+        1,
+        15,
+        tz="America/Los_Angeles",
+        fold=1,
+    )
+
+    d2 = pendulum.datetime(
+        2023,
+        11,
+        5,
+        1,
+        25,
+        tz="America/Los_Angeles",
+        fold=0,
+    )
+
+    assert d1.timestamp() > d2.timestamp()
+
+    # Verify rich ordering operators behave consistently when fold differs but
+    # the absolute instant (timestamp) shows d1 is later than d2.
+    assert not (d1 < d2)
+    assert d1 > d2
+    assert d2 < d1
+    assert d1 >= d2
+    assert not (d1 <= d2)