Revert whatsnew entry

Author: Matt Roeschke

doc/source/whatsnew/v0.24.0.txt

@@ -293,46 +293,6 @@ that the dates have been converted to UTC
 
     pd.to_datetime(["2015-11-18 15:30:00+05:30", "2015-11-18 16:30:00+06:30"], utc=True)
 
-.. _whatsnew_0240.api_breaking.calendarday:
-
-CalendarDay Offset
-^^^^^^^^^^^^^^^^^^
-
-:class:`Day` and associated frequency alias ``'D'`` were documented to represent
-a calendar day; however, arithmetic and operations with :class:`Day` sometimes
-respected absolute time instead (i.e. ``Day(n)`` and acted identically to ``Timedelta(days=n)``).
-
-*Previous Behavior*:
-
-.. code-block:: ipython
-
-
-    In [2]: ts = pd.Timestamp('2016-10-30 00:00:00', tz='Europe/Helsinki')
-
-    # Respects calendar arithmetic
-    In [3]: pd.date_range(start=ts, freq='D', periods=3)
-    Out[3]:
-    DatetimeIndex(['2016-10-30 00:00:00+03:00', '2016-10-31 00:00:00+02:00',
-                   '2016-11-01 00:00:00+02:00'],
-                  dtype='datetime64[ns, Europe/Helsinki]', freq='D')
-
-    # Respects absolute arithmetic
-    In [4]: ts + pd.tseries.frequencies.to_offset('D')
-    Out[4]: Timestamp('2016-10-30 23:00:00+0200', tz='Europe/Helsinki')
-
-:class:`CalendarDay` and associated frequency alias ``'CD'`` are now available
-and respect calendar day arithmetic while :class:`Day` and frequency alias ``'D'``
-will now respect absolute time (:issue:`22274`, :issue:`20596`, :issue:`16980`, :issue:`8774`)
-See the :ref:`documentation here <timeseries.dayvscalendarday>` for more information.
-
-Addition with :class:`CalendarDay` across a daylight savings time transition:
-
-.. ipython:: python
-
-   ts = pd.Timestamp('2016-10-30 00:00:00', tz='Europe/Helsinki')
-   ts + pd.offsets.Day(1)
-   ts + pd.offsets.CalendarDay(1)
-
 .. _whatsnew_0240.api_breaking.period_end_time:
 
 Time values in ``dt.end_time`` and ``to_timestamp(how='end')``