diff --git a/doc/source/whatsnew/v1.2.0.rst b/doc/source/whatsnew/v1.2.0.rst
index 0cfe010b63a6f..9c8ee10a8a0af 100644
--- a/doc/source/whatsnew/v1.2.0.rst
+++ b/doc/source/whatsnew/v1.2.0.rst
@@ -176,7 +176,8 @@ Datetimelike
 - Bug in :attr:`DatetimeArray.date` where a ``ValueError`` would be raised with a read-only backing array (:issue:`33530`)
 - Bug in ``NaT`` comparisons failing to raise ``TypeError`` on invalid inequality comparisons (:issue:`35046`)
 - Bug in :class:`DateOffset` where attributes reconstructed from pickle files differ from original objects when input values exceed normal ranges (e.g months=12) (:issue:`34511`)
--
+- Bug in :meth:`DatetimeIndex.get_slice_bound` where ``datetime.date`` objects were not accepted or naive :class:`Timestamp` with a tz-aware :class:`DatetimeIndex` (:issue:`35690`)
+- Bug in :meth:`DatetimeIndex.slice_locs` where ``datetime.date`` objects were not accepted (:issue:`34077`)
 
 Timedelta
 ^^^^^^^^^
diff --git a/pandas/core/indexes/datetimes.py b/pandas/core/indexes/datetimes.py
index e66f513e347a9..6dcb9250812d0 100644
--- a/pandas/core/indexes/datetimes.py
+++ b/pandas/core/indexes/datetimes.py
@@ -632,7 +632,7 @@ def get_loc(self, key, method=None, tolerance=None):
             raise KeyError(orig_key) from err
 
     def _maybe_cast_for_get_loc(self, key) -> Timestamp:
-        # needed to localize naive datetimes
+        # needed to localize naive datetimes or dates (GH 35690)
         key = Timestamp(key)
         if key.tzinfo is None:
             key = key.tz_localize(self.tz)
@@ -677,8 +677,7 @@ def _maybe_cast_slice_bound(self, label, side: str, kind):
             if self._is_strictly_monotonic_decreasing and len(self) > 1:
                 return upper if side == "left" else lower
             return lower if side == "left" else upper
-        else:
-            return label
+        return self._maybe_cast_for_get_loc(label)
 
     def _get_string_slice(self, key: str, use_lhs: bool = True, use_rhs: bool = True):
         freq = getattr(self, "freqstr", getattr(self, "inferred_freq", None))
diff --git a/pandas/tests/indexes/base_class/test_indexing.py b/pandas/tests/indexes/base_class/test_indexing.py
new file mode 100644
index 0000000000000..196c0401a72be
--- /dev/null
+++ b/pandas/tests/indexes/base_class/test_indexing.py
@@ -0,0 +1,26 @@
+import pytest
+
+from pandas import Index
+
+
+class TestGetSliceBounds:
+    @pytest.mark.parametrize("kind", ["getitem", "loc", None])
+    @pytest.mark.parametrize("side, expected", [("left", 4), ("right", 5)])
+    def test_get_slice_bounds_within(self, kind, side, expected):
+        index = Index(list("abcdef"))
+        result = index.get_slice_bound("e", kind=kind, side=side)
+        assert result == expected
+
+    @pytest.mark.parametrize("kind", ["getitem", "loc", None])
+    @pytest.mark.parametrize("side", ["left", "right"])
+    @pytest.mark.parametrize(
+        "data, bound, expected", [(list("abcdef"), "x", 6), (list("bcdefg"), "a", 0)],
+    )
+    def test_get_slice_bounds_outside(self, kind, side, expected, data, bound):
+        index = Index(data)
+        result = index.get_slice_bound(bound, kind=kind, side=side)
+        assert result == expected
+
+    def test_get_slice_bounds_invalid_side(self):
+        with pytest.raises(ValueError, match="Invalid value for side kwarg"):
+            Index([]).get_slice_bound("a", kind=None, side="middle")
diff --git a/pandas/tests/indexes/datetimes/test_indexing.py b/pandas/tests/indexes/datetimes/test_indexing.py
index 5d2c6daba3f57..539d9cb8f06a7 100644
--- a/pandas/tests/indexes/datetimes/test_indexing.py
+++ b/pandas/tests/indexes/datetimes/test_indexing.py
@@ -6,7 +6,7 @@
 from pandas.errors import InvalidIndexError
 
 import pandas as pd
-from pandas import DatetimeIndex, Index, Timestamp, date_range, notna
+from pandas import DatetimeIndex, Index, Timestamp, bdate_range, date_range, notna
 import pandas._testing as tm
 
 from pandas.tseries.offsets import BDay, CDay
@@ -665,3 +665,43 @@ def test_get_value(self):
         with tm.assert_produces_warning(FutureWarning):
             result = dti.get_value(ser, key.to_datetime64())
         assert result == 7
+
+
+class TestGetSliceBounds:
+    @pytest.mark.parametrize("box", [date, datetime, Timestamp])
+    @pytest.mark.parametrize("kind", ["getitem", "loc", None])
+    @pytest.mark.parametrize("side, expected", [("left", 4), ("right", 5)])
+    def test_get_slice_bounds_datetime_within(
+        self, box, kind, side, expected, tz_aware_fixture
+    ):
+        # GH 35690
+        index = bdate_range("2000-01-03", "2000-02-11").tz_localize(tz_aware_fixture)
+        result = index.get_slice_bound(
+            box(year=2000, month=1, day=7), kind=kind, side=side
+        )
+        assert result == expected
+
+    @pytest.mark.parametrize("box", [date, datetime, Timestamp])
+    @pytest.mark.parametrize("kind", ["getitem", "loc", None])
+    @pytest.mark.parametrize("side", ["left", "right"])
+    @pytest.mark.parametrize("year, expected", [(1999, 0), (2020, 30)])
+    def test_get_slice_bounds_datetime_outside(
+        self, box, kind, side, year, expected, tz_aware_fixture
+    ):
+        # GH 35690
+        index = bdate_range("2000-01-03", "2000-02-11").tz_localize(tz_aware_fixture)
+        result = index.get_slice_bound(
+            box(year=year, month=1, day=7), kind=kind, side=side
+        )
+        assert result == expected
+
+    @pytest.mark.parametrize("box", [date, datetime, Timestamp])
+    @pytest.mark.parametrize("kind", ["getitem", "loc", None])
+    def test_slice_datetime_locs(self, box, kind, tz_aware_fixture):
+        # GH 34077
+        index = DatetimeIndex(["2010-01-01", "2010-01-03"]).tz_localize(
+            tz_aware_fixture
+        )
+        result = index.slice_locs(box(2010, 1, 1), box(2010, 1, 2))
+        expected = (0, 1)
+        assert result == expected
diff --git a/pandas/tests/indexes/test_numeric.py b/pandas/tests/indexes/test_numeric.py
index e6f455e60eee3..1ffdbbc9afd3f 100644
--- a/pandas/tests/indexes/test_numeric.py
+++ b/pandas/tests/indexes/test_numeric.py
@@ -679,3 +679,22 @@ def test_float64_index_difference():
 
     result = string_index.difference(float_index)
     tm.assert_index_equal(result, string_index)
+
+
+class TestGetSliceBounds:
+    @pytest.mark.parametrize("kind", ["getitem", "loc", None])
+    @pytest.mark.parametrize("side, expected", [("left", 4), ("right", 5)])
+    def test_get_slice_bounds_within(self, kind, side, expected):
+        index = Index(range(6))
+        result = index.get_slice_bound(4, kind=kind, side=side)
+        assert result == expected
+
+    @pytest.mark.parametrize("kind", ["getitem", "loc", None])
+    @pytest.mark.parametrize("side", ["left", "right"])
+    @pytest.mark.parametrize(
+        "bound, expected", [(-1, 0), (10, 6)],
+    )
+    def test_get_slice_bounds_outside(self, kind, side, expected, bound):
+        index = Index(range(6))
+        result = index.get_slice_bound(bound, kind=kind, side=side)
+        assert result == expected