Fix errors where hours and days were not handled correctly when addin…

…g durations (#775)

Fixes #768

src/pendulum/datetime.py

@@ -685,9 +685,7 @@ def _add_timedelta_(self, delta: datetime.timedelta) -> Self:
                 microseconds=delta.microseconds,
             )
         elif isinstance(delta, pendulum.Duration):
-            return self.add(
-                years=delta.years, months=delta.months, seconds=delta._total
-            )
+            return self.add(**delta._signature)  # type: ignore[attr-defined]
 
         return self.add(seconds=delta.total_seconds())
 

src/pendulum/duration.py

@@ -112,6 +112,17 @@ def __new__(
         self._months = months
         self._years = years
 
+        self._signature = {  # type: ignore[attr-defined]
+            "years": years,
+            "months": months,
+            "weeks": weeks,
+            "days": days,
+            "hours": hours,
+            "minutes": minutes,
+            "seconds": seconds,
+            "microseconds": microseconds + milliseconds * 1000,
+        }
+
         return self
 
     def total_minutes(self) -> float:
@@ -440,7 +451,10 @@ def __mod__(self, other: timedelta) -> Self:
 
     def __divmod__(self, other: timedelta) -> tuple[int, Duration]:
         if isinstance(other, timedelta):
-            q, r = divmod(self._to_microseconds(), other._to_microseconds())  # type: ignore[attr-defined] # noqa: E501
+            q, r = divmod(
+                self._to_microseconds(),
+                other._to_microseconds(),  # type: ignore[attr-defined]
+            )
 
             return q, self.__class__(0, 0, r)
 

tests/datetime/test_add.py

@@ -252,13 +252,25 @@ def test_add_time_to_new_transition_repeated_big():
     assert not dt.is_dst()
 
 
-def test_add_interval():
+def test_add_duration_across_transition():
     dt = pendulum.datetime(2017, 3, 11, 10, 45, tz="America/Los_Angeles")
     new = dt + pendulum.duration(hours=24)
 
     assert_datetime(new, 2017, 3, 12, 11, 45)
 
 
+def test_add_duration_across_transition_days():
+    dt = pendulum.datetime(2017, 3, 11, 10, 45, tz="America/Los_Angeles")
+    new = dt + pendulum.duration(days=1)
+
+    assert_datetime(new, 2017, 3, 12, 10, 45)
+
+    dt = pendulum.datetime(2023, 11, 5, 0, 0, tz="America/Chicago")
+    new = dt + pendulum.duration(days=1)
+
+    assert_datetime(new, 2023, 11, 6, 0, 0)
+
+
 def test_interval_over_midnight_tz():
     start = pendulum.datetime(2018, 2, 25, tz="Europe/Paris")
     end = start.add(hours=1)