Q: How do you add dates to multiple contacts? For example, closing date for both the transaction coordinator and the listing agent? If you add someone to the "with" section and they are a user, will the dates appear on their calendar also?
A: If they are users then it has to be in the "Assign To" in order for it to show in their calendar. You just make 2 copies of that activity - one for the "Listing Agent and one for the Transaction Coordinator. You can give them different "Colors" if you like - that way both will have event on their calendar.