Summary
a) Reduction in vacant slots without details of participants:
Use our “Availability management Anchor (Quota Management)” option and reduce the maximum availability for participant numbers individually by date in the calendar daily view. (So vacant booking slots will only be displayed if there are no old bookings.)
b) Reduction in vacant slots including details of participants:
For each date, you manually transfer your old bookings including all information on participants via the function “Add booking”.