BUG: BDay() offsetting not behaving as expected

Author: theoniko

pandas/tests/tseries/offsets/test_offsets.py

@@ -19,6 +19,7 @@
 from pandas.compat.numpy import np_datetime64_compat
 from pandas.errors import PerformanceWarning
 
+import pandas as pd
 import pandas._testing as tm
 from pandas.core.indexes.datetimes import DatetimeIndex, date_range
 from pandas.core.series import Series
@@ -2326,6 +2327,36 @@ def test_datetimeindex(self):
         for idx in [idx1, idx2, idx3]:
             tm.assert_index_equal(idx, expected)
 
+    def test_bday_ignores_timedeltas(self):
+        idx = pd.date_range("2010/02/01", "2010/02/10", freq="12H")
+        t1 = idx + BDay(offset=pd.Timedelta(3, unit="H"))
+
+        expected = DatetimeIndex(
+            [
+                "2010-02-02 03:00:00",
+                "2010-02-02 15:00:00",
+                "2010-02-03 03:00:00",
+                "2010-02-03 15:00:00",
+                "2010-02-04 03:00:00",
+                "2010-02-04 15:00:00",
+                "2010-02-05 03:00:00",
+                "2010-02-05 15:00:00",
+                "2010-02-08 03:00:00",
+                "2010-02-08 15:00:00",
+                "2010-02-08 03:00:00",
+                "2010-02-08 15:00:00",
+                "2010-02-08 03:00:00",
+                "2010-02-08 15:00:00",
+                "2010-02-09 03:00:00",
+                "2010-02-09 15:00:00",
+                "2010-02-10 03:00:00",
+                "2010-02-10 15:00:00",
+                "2010-02-11 03:00:00",
+            ],
+            freq=None,
+        )
+        tm.assert_index_equal(t1, expected)
+
 
 class TestCustomBusinessHour(Base):
     _offset = CustomBusinessHour