document changes for YearArchiveView.

docs/ref/class-based-views/generic-date-based.txt

@@ -87,16 +87,24 @@ YearArchiveView
     * ``year``: A :class:`~datetime.date` object
       representing the given year.
 
+      .. versionchanged:: 1.5
+
+      Previously, this returned a string.
+
     * ``next_year``: A :class:`~datetime.date` object
       representing the first day of the next year, according to
       :attr:`~BaseDateListView.allow_empty` and
       :attr:`~DateMixin.allow_future`.
 
+      .. versionadded:: 1.5
+
     * ``previous_year``: A :class:`~datetime.date` object
       representing the first day of the previous year, according to
       :attr:`~BaseDateListView.allow_empty` and
       :attr:`~DateMixin.allow_future`.
 
+      .. versionadded:: 1.5
+
     **Notes**
 
     * Uses a default ``template_name_suffix`` of ``_archive_year``.