BUG: fix datetimeindex repr (pandas-dev#53634)

* add bug fix for datetimeindex repr

* Add tests

* Run precommit

* Add bug fix to docs

* Add check for delta

* Fix check for delta

* Fix precheck

* Fix union-attrs mypy check

* Address Pr comments

* Reset test_datetime.py

* Fix precommit

* Fix precommit quotes

* Fix formatting

* Fix whatsnew doc

* Update tests to assert

* run precommit

* break up long line

* Fix space placement

* Add github issue number

* use datetime timedelta

* run precommit

* Fix formatting

* Use getattr

Co-authored-by: Matthew Roeschke <[email protected]>

---------

Co-authored-by: Matthew Roeschke <[email protected]>

Author: Simar-B

doc/source/whatsnew/v2.1.0.rst

@@ -626,6 +626,7 @@ Metadata
 Other
 ^^^^^
 - Bug in :class:`DataFrame` and :class:`Series` raising for data of complex dtype when ``NaN`` values are present (:issue:`53627`)
+- Bug in :class:`DatetimeIndex` where ``repr`` of index passed with time does not print time is midnight and non-day based freq(:issue:`53470`)
 - Bug in :class:`FloatingArray.__contains__` with ``NaN`` item incorrectly returning ``False`` when ``NaN`` values are present (:issue:`52840`)
 - Bug in :func:`api.interchange.from_dataframe` when converting an empty DataFrame object (:issue:`53155`)
 - Bug in :func:`assert_almost_equal` now throwing assertion error for two unequal sets (:issue:`51727`)

pandas/core/indexes/datetimes.py

@@ -393,11 +393,18 @@ def _is_dates_only(self) -> bool:
         -------
         bool
         """
+
         from pandas.io.formats.format import is_dates_only
 
+        delta = getattr(self.freq, "delta", None)
+
+        if delta and delta % dt.timedelta(days=1) != dt.timedelta(days=0):
+            return False
+
         # error: Argument 1 to "is_dates_only" has incompatible type
         # "Union[ExtensionArray, ndarray]"; expected "Union[ndarray,
         # DatetimeArray, Index, DatetimeIndex]"
+
         return self.tz is None and is_dates_only(self._values)  # type: ignore[arg-type]
 
     def __reduce__(self):

pandas/tests/indexes/datetimes/test_formats.py

@@ -68,6 +68,36 @@ def test_dti_repr_short(self):
         dr = pd.date_range(start="1/1/2012", periods=3)
         repr(dr)
 
+    @pytest.mark.parametrize(
+        "dates, freq, expected_repr",
+        [
+            (
+                ["2012-01-01 00:00:00"],
+                "60T",
+                (
+                    "DatetimeIndex(['2012-01-01 00:00:00'], "
+                    "dtype='datetime64[ns]', freq='60T')"
+                ),
+            ),
+            (
+                ["2012-01-01 00:00:00", "2012-01-01 01:00:00"],
+                "60T",
+                "DatetimeIndex(['2012-01-01 00:00:00', '2012-01-01 01:00:00'], "
+                "dtype='datetime64[ns]', freq='60T')",
+            ),
+            (
+                ["2012-01-01"],
+                "24H",
+                "DatetimeIndex(['2012-01-01'], dtype='datetime64[ns]', freq='24H')",
+            ),
+        ],
+    )
+    def test_dti_repr_time_midnight(self, dates, freq, expected_repr):
+        # GH53634
+        dti = DatetimeIndex(dates, freq)
+        actual_repr = repr(dti)
+        assert actual_repr == expected_repr
+
     @pytest.mark.parametrize("method", ["__repr__", "__str__"])
     def test_dti_representation(self, method):
         idxs = []