Block an entire day - Wix Booking (CLASSES)

Unfortunately, it seems there is no way to block a day in Wix Booking if you’re using classes as the appointment type

Neither “Blocked Time”. nor the removal of the staff’s “work schedule” for the day

So, instead of manually cancelling all class sessions for every holiday that comes up - I want to use the WixBooking API to just cancel a selected date

Is this possible?
When querying sessions I get their general state, as in [runs from x to y every week]

How do I get specifically to the schedules of a certain day?