BUG: bug in date_range with custom business hours and given periods

doc/source/whatsnew/v1.0.0.rst

@@ -833,6 +833,7 @@ Datetimelike
 - Bug in :meth:`Series.cummin` and :meth:`Series.cummax` with timezone-aware dtype incorrectly dropping its timezone (:issue:`15553`)
 - Bug in :class:`DatetimeArray`, :class:`TimedeltaArray`, and :class:`PeriodArray` where inplace addition and subtraction did not actually operate inplace (:issue:`24115`)
 - Bug in :func:`pandas.to_datetime` when called with ``Series`` storing ``IntegerArray`` raising ``TypeError`` instead of returning ``Series`` (:issue:`30050`)
+- Bug in :func:`date_range` with custom business hours as ``freq`` and given number of ``periods`` (:issue:`30593`)
 
 Timedelta
 ^^^^^^^^^

pandas/tests/indexes/datetimes/test_date_range.py

@@ -945,3 +945,19 @@ def test_range_with_millisecond_resolution(self, start_end):
         result = pd.date_range(start=start, end=end, periods=2, closed="left")
         expected = DatetimeIndex([start])
         tm.assert_index_equal(result, expected)
+
+
+def test_date_range_with_custom_holidays():
+    # GH 30593
+    freq = pd.offsets.CustomBusinessHour(start="15:00", holidays=["2020-11-26"])
+    result = pd.date_range(start="2020-11-25 15:00", periods=4, freq=freq)
+    expected = pd.DatetimeIndex(
+        [
+            "2020-11-25 15:00:00",
+            "2020-11-25 16:00:00",
+            "2020-11-27 15:00:00",
+            "2020-11-27 16:00:00",
+        ],
+        freq=freq,
+    )
+    tm.assert_index_equal(result, expected)

pandas/tseries/offsets.py

@@ -896,7 +896,15 @@ def apply(self, other):
 
             # adjust by business days first
             if bd != 0:
-                skip_bd = BusinessDay(n=bd)
+                if isinstance(self, _CustomMixin):  # GH 30593
+                    skip_bd = CustomBusinessDay(
+                        n=bd,
+                        weekmask=self.weekmask,
+                        holidays=self.holidays,
+                        calendar=self.calendar,
+                    )
+                else:
+                    skip_bd = BusinessDay(n=bd)
                 # midnight business hour may not on BusinessDay
                 if not self.next_bday.is_on_offset(other):
                     prev_open = self._prev_opening_time(other)