Calendar events may be tagged as "exclusive". The user can select in settings if new entries will default to exclusive or not.

Any time an exclusive event overlaps with another exclusive event, the user is given a warning about the conflict, so they can then decide how to resolve it.

If two exclusive events are booked close to each other and they both have addresses listed, an estimated travel time could be generated and a warning given if there isn't going to be enough time to travel from one location to the next.

This will be beneficial when importing events via ICS or Google calendar, using a shared family calendar alongside a shared work calendar etc.