Declined appointments are not returned by this endpoint.
Recurring appointments are stored once and expanded into one appointment object per occurrence
that falls within start_date/end_date. Occurrences that haven't been individually modified
share the base appointment's id; once an occurrence's status is changed (for example, checking
a patient in), it's returned as its own appointment with a new id and a recurring_appointment_id
pointing back to the original recurring appointment. See Recurring Appointments
for details, including what happens when a series is edited after an occurrence has already split off.