Comment 0 for bug 207604

The Debian/Ubuntu packages of pytz include a patch to not install pytz's zoneinfo database and instead load data from the system zoneinfo database. This keeps pytz up to date when system timezone updates are installed which is generally a good idea.

The pytz/__init__.py includes common_timezones and all_timezones lists, which enumerate the time zones in the database pytz was released with. If pytz is instead using the system database, these lists may not be correct (e.g. missing newly added time zones).

It would be nice if pytz could calculate these lists from data found in the zoneinfo directory it is pointed at. If it isn't possible to do this with what tzdata currently installs, this might require it to install an extra index file.