Ok, I've put a new item into the site configuration that defines a default
time zone to be assumed when a calendar item is not UTC but does not have
any time zone defined. Frankly I think these calendar items are broken to
begin with, but since they exist, we need to contend with them.
The per-user setting is a good idea, but I don't have any way to convert
an Olsen time zone to a Unix time zone, so it would only work for
calendars -- not for timestamps on messages or anything else in the
system. If someone finds a way around this issue, I will add the per-user
timezone.
My next project is going to be the modification of imap_do_expunge() and
CtdlDeleteMessages() to use the new bulk-move API. This will *hopefully*
be the final step in improving the response time when you move or delete a
big block of messages using IMAP and you've got 30,000 messages in your
Trash folder. (Yes, I know ... empty the trash. The problem is that I
have an important user at an important site for whom "Trash" doesn't mean
"Trash" -- it means "My Archive Of All Important Historical Emails")