A button in the email reminders or "Reply Yes to confirm appt" in SMS reminders that allow the client to physically confirm, and have the schedule show them as confirmed if they do, from both the shedule view and in each appointment. We feel this would drastically decrease no-shows, and provide more time to fill appointments that forgot to cancel in good time.

Possible suggestions on how to show this: perhaps a thin green bar across the top of the appointment (schedule view) or a green checkmark, or even the word "confirmed" or conf'd beside the time range. Conversely a red bar or red x to show they are not confirmed.
Anything that would allow us to look at the schedule/calendar view and know who confirmed when they got their reminder and who didn't. Thank you.