Is there a way to alter room booking rules based on date?

I work at a small College, and we are currently running Exchange 2010 SP1 (Update Rollup 8).

After the school year ends, (at the end of April) and the summer begins, the school changes modes to more of a conference center.

As such, our business rules for booking rooms on campus change from anyone being able to book a room, to all bookings needing to go through our conference director.  The conferences director is set as a delegate for all rooms currently.

My question is this:  Is there a way in Exchange 2010 to have different sets of rules enacted based on the booking date?  For example, if the booking time is between September and April, process it automatically, but if the booking time is from April to September, forward all requests to the delegate.

Any help would be appreciated.