We're looking at this as a permanent option and using the free trial to see how it goes - I can't seem to see where to find adding 'ad hoc appointments' as we'll be doing clinic bookings at random times, so perhaps:
This week: Monday 3pm, 4pm, 5pm
Next week: Tuesday 2pm, 3pm
Week after: Monday 2pm, 3pm, Thursday 5pm
Is there an option to easily add when appointments are 'available' to book?