Fixed DatetimeIndex.tz_convert() .freq attribute

pandas/_libs/tslibs/offsets.pyx

@@ -1373,6 +1373,25 @@ class DateOffset(RelativeDeltaOffset, metaclass=OffsetMeta):
         previous midnight.
     **kwds
         Temporal parameter that add to or replace the offset value.
+    weekday : int {0, 1, ..., 6}, default 0
+
+        A specific integer for the day of the week.
+        - 0 is Monday
+        - 1 is Tuesday
+        - 2 is Wednesday
+        - 3 is Thursday
+        - 4 is Friday
+        - 5 is Saturday
+        - 6 is Sunday.
+
+        Instead Weekday type from dateutil.relativedelta can be used.
+        - MO is Monday
+        - TU is Tuesday
+        - WE is Wednesday
+        - TH is Thursday
+        - FR is Friday
+        - SA is Saturday
+        - SU is Sunday.
 
         Parameters that **add** to the offset (like Timedelta):
 

pandas/core/arrays/datetimes.py

@@ -824,7 +824,8 @@ def _local_timestamps(self) -> npt.NDArray[np.int64]:
 
     def tz_convert(self, tz) -> Self:
         """
-        Convert tz-aware Datetime Array/Index from one time zone to another.
+        Convert tz-aware Datetime Array/Index from one time zone to another
+        and sets frequency to None.
 
         Parameters
         ----------
@@ -866,7 +867,7 @@ def tz_convert(self, tz) -> Self:
         DatetimeIndex(['2014-08-01 02:00:00-05:00',
                        '2014-08-01 03:00:00-05:00',
                        '2014-08-01 04:00:00-05:00'],
-                      dtype='datetime64[ns, US/Central]', freq='H')
+                      dtype='datetime64[ns, US/Central]')
 
         With the ``tz=None``, we can remove the timezone (after converting
         to UTC if necessary):
@@ -884,7 +885,7 @@ def tz_convert(self, tz) -> Self:
         DatetimeIndex(['2014-08-01 07:00:00',
                        '2014-08-01 08:00:00',
                        '2014-08-01 09:00:00'],
-                        dtype='datetime64[ns]', freq='H')
+                        dtype='datetime64[ns]')
         """
         tz = timezones.maybe_get_tz(tz)
 
@@ -896,7 +897,7 @@ def tz_convert(self, tz) -> Self:
 
         # No conversion since timestamps are all UTC to begin with
         dtype = tz_to_dtype(tz, unit=self.unit)
-        return self._simple_new(self._ndarray, dtype=dtype, freq=self.freq)
+        return self._simple_new(self._ndarray, dtype=dtype)
 
     @dtl.ravel_compat
     def tz_localize(

pandas/tests/indexes/datetimes/test_timezones.py

@@ -102,6 +102,12 @@ def test_tz_convert_nat(self):
         expected = ["2010-12-01 11:00", "2010-12-02 11:00", pd.NaT]
         tm.assert_index_equal(idx, DatetimeIndex(expected, tz="US/Eastern"))
 
+    def test_tz_convert_freq(self):
+        i = date_range("2020-03-27 06:00", freq="D", periods=5, tz="Europe/Berlin")
+
+        i2 = i.tz_convert("UTC")
+        assert i2.freq is None
+
     @pytest.mark.parametrize("prefix", ["", "dateutil/"])
     def test_dti_tz_convert_compat_timestamp(self, prefix):
         strdates = ["1/1/2012", "3/1/2012", "4/1/2012"]
@@ -880,7 +886,7 @@ def test_dti_tz_conversion_freq(self, tz_naive_fixture):
         t3 = DatetimeIndex(["2019-01-01 10:00"], freq="H")
         assert t3.tz_localize(tz=tz_naive_fixture).freq == t3.freq
         t4 = DatetimeIndex(["2019-01-02 12:00"], tz="UTC", freq="T")
-        assert t4.tz_convert(tz="UTC").freq == t4.freq
+        assert t4.tz_convert(tz="UTC").freq is None
 
     def test_drop_dst_boundary(self):
         # see gh-18031