BUG fix for date_range 56134 (pandas-dev#56831)

Author: jrmylow

doc/source/whatsnew/v2.3.0.rst

@@ -118,7 +118,7 @@ Categorical
 
 Datetimelike
 ^^^^^^^^^^^^
--
+- Bug in :func:`date_range` where the last valid timestamp would sometimes not be produced (:issue:`56134`)
 -
 
 Timedelta

pandas/core/arrays/datetimes.py

@@ -2775,11 +2775,6 @@ def _generate_range(
         # variable has type "Optional[Timestamp]")
         start = offset.rollforward(start)  # type: ignore[assignment]
 
-    elif end and not offset.is_on_offset(end):
-        # Incompatible types in assignment (expression has type "datetime",
-        # variable has type "Optional[Timestamp]")
-        end = offset.rollback(end)  # type: ignore[assignment]
-
     # Unsupported operand types for < ("Timestamp" and "None")
     if periods is None and end < start and offset.n >= 0:  # type: ignore[operator]
         end = None

pandas/tests/indexes/datetimes/test_date_range.py

@@ -1703,3 +1703,18 @@ def test_date_range_freqstr_matches_offset(self, freqstr, offset):
         idx2 = date_range(start=sdate, end=edate, freq=offset)
         assert len(idx1) == len(idx2)
         assert idx1.freq == idx2.freq
+
+    def test_date_range_partial_day_year_end(self, unit):
+        # GH#56134
+        rng = date_range(
+            start="2021-12-31 00:00:01",
+            end="2023-10-31 00:00:00",
+            freq="YE",
+            unit=unit,
+        )
+        exp = DatetimeIndex(
+            ["2021-12-31 00:00:01", "2022-12-31 00:00:01"],
+            dtype=f"M8[{unit}]",
+            freq="YE",
+        )
+        tm.assert_index_equal(rng, exp)