From f45e53b399b954b71c81dec35962aa6f0880eba3 Mon Sep 17 00:00:00 2001
From: lpc <lpintocastaneda@gmail.com>
Date: Wed, 13 Apr 2022 21:08:19 +0200
Subject: [PATCH 1/3] GH46331: add tests

---
 .../indexes/datetimes/test_date_range.py      | 28 +++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/pandas/tests/indexes/datetimes/test_date_range.py b/pandas/tests/indexes/datetimes/test_date_range.py
index 377974a918ad9..965070d31a088 100644
--- a/pandas/tests/indexes/datetimes/test_date_range.py
+++ b/pandas/tests/indexes/datetimes/test_date_range.py
@@ -783,6 +783,34 @@ def test_range_where_start_equal_end(self, inclusive_endpoints_fixture):
 
         tm.assert_index_equal(result, expected)
 
+    def test_range_without_start_inclusive(self, inclusive_endpoints_fixture):
+        # GH 46331
+        start = Timestamp("2000-01-01")
+        end = Timestamp("2000-01-04")
+        both_range = date_range(start, end, inclusive="both")
+
+        result = date_range(end=end, periods=4, inclusive=inclusive_endpoints_fixture)
+        expected = _get_expected_range(
+            start, end, both_range, inclusive_endpoints_fixture
+        )
+
+        tm.assert_index_equal(result, expected)
+
+    def test_range_without_end_inclusive(self, inclusive_endpoints_fixture):
+        # GH 46331
+        start = Timestamp("2000-01-01")
+        end = Timestamp("2000-01-04")
+        both_range = date_range(start, end, inclusive="both")
+
+        result = date_range(
+            start=start, periods=4, inclusive=inclusive_endpoints_fixture
+        )
+        expected = _get_expected_range(
+            start, end, both_range, inclusive_endpoints_fixture
+        )
+
+        tm.assert_index_equal(result, expected)
+
 
 class TestDateRangeTZ:
     """Tests for date_range with timezones"""

From 5660addeca63123c5f60eade3024138977530f29 Mon Sep 17 00:00:00 2001
From: luis pinto <luispintocastaneda@gmail.com>
Date: Fri, 8 Apr 2022 17:45:54 +0200
Subject: [PATCH 2/3] GH46331: take into account start/end being None

---
 pandas/core/arrays/datetimes.py | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/pandas/core/arrays/datetimes.py b/pandas/core/arrays/datetimes.py
index 95882b65e9aaa..f8defc23f3b3a 100644
--- a/pandas/core/arrays/datetimes.py
+++ b/pandas/core/arrays/datetimes.py
@@ -484,17 +484,21 @@ def _generate_range(
                 #  to overflow and cast to e.g. f8, but if it does we need to cast
                 i8values = i8values.astype("i8")
 
+        # Apply `inclusive` rules
         if start == end:
+            # Particular case where we act iff `inclusive="neither"`
+            # cf. GH #43394
             if not left_inclusive and not right_inclusive:
                 i8values = i8values[1:-1]
-        else:
+        elif len(i8values):
             start_i8 = Timestamp(start).value
             end_i8 = Timestamp(end).value
-            if not left_inclusive or not right_inclusive:
-                if not left_inclusive and len(i8values) and i8values[0] == start_i8:
-                    i8values = i8values[1:]
-                if not right_inclusive and len(i8values) and i8values[-1] == end_i8:
-                    i8values = i8values[:-1]
+            _left, _right = None, None
+            if not left_inclusive and (i8values[0] == start_i8 or start is None):
+                _left = 1
+            if not right_inclusive and (i8values[-1] == end_i8 or end is None):
+                _right = -1
+            i8values = i8values[_left:_right]
 
         dt64_values = i8values.view("datetime64[ns]")
         dtype = tz_to_dtype(tz)

From 484102401c871f3b7b04b3ebc236386b6dd7cd08 Mon Sep 17 00:00:00 2001
From: lpc <lpintocastaneda@gmail.com>
Date: Wed, 13 Apr 2022 22:38:19 +0200
Subject: [PATCH 3/3] GH46331: whatsnew

---
 doc/source/whatsnew/v1.5.0.rst | 1 +
 1 file changed, 1 insertion(+)

diff --git a/doc/source/whatsnew/v1.5.0.rst b/doc/source/whatsnew/v1.5.0.rst
index 358d9447b131d..e96f88d37f52f 100644
--- a/doc/source/whatsnew/v1.5.0.rst
+++ b/doc/source/whatsnew/v1.5.0.rst
@@ -473,6 +473,7 @@ Datetimelike
 - Bug in :meth:`Index.astype` when casting from object dtype to ``timedelta64[ns]`` dtype incorrectly casting ``np.datetime64("NaT")`` values to ``np.timedelta64("NaT")`` instead of raising (:issue:`45722`)
 - Bug in :meth:`SeriesGroupBy.value_counts` index when passing categorical column (:issue:`44324`)
 - Bug in :meth:`DatetimeIndex.tz_localize` localizing to UTC failing to make a copy of the underlying data (:issue:`46460`)
+- Bug in :meth:`date_range` when ``start`` or ``end`` was not specified, failed to exclude first or last date despite ``inclusive`` not being ``"both"`` (:issue:`46331`)
 -
 
 Timedelta