Inspired by: http://docs.webfaction.com/software/zope-and-plone/configuring.html
Sometime you download a datafs from a server located in USA.
but you are working in European timezone.
to avoid confusion add the timezoneinfo in the buildout so server and your local has the same timezone.
to do this
add this section environment-vars if not there then add the line below it:
then save the file and rerun buildout.
that will make your local or maybe another server where u install plone using same timezone info.
hope this helps