How to mark/report on attendance?

Business problem:

If I create a calendar for any business function, is it possible to identify which appointments customers actually show up?

Example:

A physio has 10 appointments booked for any given day, some days customers will not attend *without*  directly cancelling (i.e. they just don't show up).

At the end of the week, how can the business report on/identify the appointments that were missed?

e.g. Can you set a status on an appointment when someone arrives?