The ability to link project member calendars to Hive so that when someone is marked as out of office you cannot assign them a due date for when they are OOO, or if they mark OOO on their calendar after they've been assigned an action card due date on the same date as their OOO, Hive notifies the project manager to change the due date or reassign the action card. This could operate similarly to not being able to assign due dates on weekends or holidays, for example.