Please Note: Instead of applying this patch, you will most likely want to use Zope 2.6.1 or later, which has this and numerous other bugs fixed.

Zope 2.6.0 has a bug in DateTime.rfc822(). The bug appears when you are NOT in a DST timezone, causing a "Name Error: global name localzone is not defined" error.

This will affect many parts of your Zope operations, luckily, the fix is simple:

Download this fixed DateTime.py, and put it into the lib/python/DateTime directory, replacing the one that is there, and then restart the server.

This fix is ONLY valid for Zope 2.6.0. Earlier versions of Zope does not have this bug, and this bugfix will be included in any future releases of Zope.