I know that some calendars have “busy” and “free” slots. That’s all great. However, I really want “Tentative” slots and I would really like them to have some sort of expiration as well as a different UI treatment for them as well.
This would make calendaring much easier for me, because I can easily add things that I would like to see happen or things I am talking with people about, but not have them me permanent.
Additionally, having the calendar “react” when I plan something overtop or at the same time as a tentative event would be awesome. “You have an overlapping tentative event, would you like to cancel this event?”