The base pytz package is patched to use the system zoneinfo files. The Python 3 version has not been patched, so it includes it own out of date copy of the files.
pytz-2015.4-1.fc23 has been submitted as an update to Fedora 23. https://bodhi.fedoraproject.org/updates/FEDORA-2015-14677
pytz-2015.4-1.fc23 has been pushed to the Fedora 23 testing repository. If problems still persist, please make note of it in this bug report.\nIf you want to test the update, you can install it with \n su -c 'yum --enablerepo=updates-testing update pytz'. You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2015-14677
This package has changed ownership in the Fedora Package Database. Reassigning to the new owner of this component.
pytz-2015.4-1.fc23 has been pushed to the Fedora 23 stable repository. If problems still persist, please make note of it in this bug report.