BUG: Using DatetimeIndex.date with timezone returns incorrect date #2…

doc/source/whatsnew/v0.23.1.txt

@@ -86,6 +86,7 @@ Indexing
 - Bug in :meth:`Series.reset_index` where appropriate error was not raised with an invalid level name (:issue:`20925`)
 - Bug in :func:`interval_range` when ``start``/``periods`` or ``end``/``periods`` are specified with float ``start`` or ``end`` (:issue:`21161`)
 - Bug in :meth:`MultiIndex.set_names` where error raised for a ``MultiIndex`` with ``nlevels == 1`` (:issue:`21149`)
+- Bug in :attr:`DatetimeIndex.date` where an incorrect date is returned when the input date has a non-UTC timezone (:issue:`21230`)
 - Bug in :class:`IntervalIndex` constructors where creating an ``IntervalIndex`` from categorical data was not fully supported (:issue:`21243`, issue:`21253`)
 -
 

pandas/core/indexes/datetimes.py

@@ -2040,7 +2040,16 @@ def date(self):
         Returns numpy array of python datetime.date objects (namely, the date
         part of Timestamps without timezone information).
         """
-        return libts.ints_to_pydatetime(self.normalize().asi8, box="date")
+
+        # If the Timestamps have a timezone that is not UTC,
+        # convert them into their i8 representation while
+        # keeping their timezone and not using UTC
+        if (self.tz is not None and self.tz is not utc):
+            timestamps = self._local_timestamps()
+        else:
+            timestamps = self.asi8
+
+        return libts.ints_to_pydatetime(timestamps, box="date")
 
     def normalize(self):
         """

pandas/tests/indexes/datetimes/test_timezones.py

@@ -2,7 +2,7 @@
 """
 Tests for DatetimeIndex timezone-related methods
 """
-from datetime import datetime, timedelta, tzinfo
+from datetime import datetime, timedelta, tzinfo, date
 from distutils.version import LooseVersion
 
 import pytest
@@ -706,6 +706,19 @@ def test_join_utc_convert(self, join_type):
         assert isinstance(result, DatetimeIndex)
         assert result.tz.zone == 'UTC'
 
+    @pytest.mark.parametrize("dtype", [
+        None, 'datetime64[ns, CET]',
+        'datetime64[ns, EST]', 'datetime64[ns, UTC]'
+    ])
+    def test_date_accessor(self, dtype):
+        # Regression test for GH#21230
+        expected = np.array([date(2018, 6, 4), pd.NaT], ndmin=1)
+
+        index = DatetimeIndex(['2018-06-04 10:00:00', pd.NaT], dtype=dtype)
+        result = index.date
+
+        tm.assert_numpy_array_equal(result, expected)
+
     def test_dti_drop_dont_lose_tz(self):
         # GH#2621
         ind = date_range("2012-12-01", periods=10, tz="utc")