Hi! I've not come across a way to do this but never desired to do so. I just checked the Access Settings tab for the Website Settings screen in the Admin Console and don't see anything about the calendar. If you read the calendar description in the documentation at
support.toastmastersclubs.org/doc/item/club-calendar
, you'll notice that any member can add/delete her own event and that the administrator can delete anybody's event. No description of access restrictions. Since the documentation discusses the idea of a club having a policy with regard to members creating calendar events, I strongly believe that the answer to your query is "No."
Regards,
Art