Fixed #20891 -- Removed part of the tutorial that requires pytz

fields as you'd like -- although because it uses a ``LIKE`` query behind the

scenes, keep it reasonable, to keep your database happy.

Finally, because ``Poll`` objects have dates, it'd be convenient to be able to

drill down by date. Add this line::

    date_hierarchy = 'pub_date'

That adds hierarchical navigation, by date, to the top of the change list page.

At top level, it displays all available years. Then it drills down to months

and, ultimately, days.

Now's also a good time to note that change lists give you free pagination. The

default is to display 100 items per page. Change-list pagination, search boxes,

filters, date-hierarchies and column-header-ordering all work together like you