Hey Jérémy, I just found your mail regarding this bug in the pkg-zope-developers archive. I missed it somehow O_o. So I'll test zope2.9 from unstable, either this night or tomorrow.
Seems there were several problems in the DateTime module, which were not covered by the tests for the module. http://www.zope.org/Collectors/Zope/2191 is still not closed, so I guess we'll see some fixes regarding DateTime. I'll keep an eye on it. Cheers Bernd -- Bernd Zeimetz <[EMAIL PROTECTED]> <http://bzed.de/>