Calendar Private to Group or by Access Masks

[Doogie]

I have tried to do this, but I'd like to be able to make a calendar viewable by a certain group or access masks. I.E. by default no one has access, but the moderator can then assign access masks in order to allow people to view the calendar.

Usage:

Currently run gaming forums for clans, and each clan wants their own calendar that no one else can see.