That does make it a lot more difficult. I don't have any real answer on how to do that, but I would probably start with getting the .ics file from zimbra, and figuring out some shell/PERL script to parse through the .ics and remove things that are the same. Though it is entirely possible that there is some small difference between each entry that would make that step more difficult too.
From my previous example, you can get the ics of the user from the command line by doing:
Code:
zmmailbox -z -m user@domain.com gru -o /tmp/calendar.ics /Calendar
That will get the .ics of the user, and you can work on it from there...but of course, getting the ICS is easy, cleaning it up is certainly the hard part.