> Is there a way to prevent users from updating calendar entries for
> days that have passed? As an example, if a user has an entry in
> their calendar from yesterday, we would like to prevent them from
> updating or modifying that calendar entry. However, they still need
> the ability to update or modify calendar items for today and in the
> future.
I don't think there's any way to do that. They own the data, after all, and
there's no way to prevent someone modifying data they own.

Signature
Brian Tillman [MVP-Outlook]