assignment_calendar

Idea on creating a homework calendar
see http://venturacottage.com/tutorials/theming/homework-calendar

I've had some requests from tutors to view my class's assignment calendar. I'm using Bill's model from his book and have the assignment calendar up and running.

I would like these people to be able to view the calendar and the assignments but no more. I'm not sure how to do this. I tried to create a new role (calendar viewer) and assign just those rights, but those are not options. I also looked at the View for the assignment calendar but am frankly stumped. I don't particularly want to add these people to the class, just because I'd like to have some measure of privacy for the students.