Non delivery days
To prevent a delivery slot being displayed in your store front and booked by a shopper set a non delivery day. For example your automatic rules may cause an unwanted delivery slot to be generated on Christmas Day and setting a non-delivery day would prevent that being a problem. A non-delivery day should be set before a slot on that date is automatically generated to prevent any orders being placed for delivery on that day.
A non delivery day can be set against an individual delivery scheme or for all schemes.
The visibility of delivery slots in the control panel is unaffected by non delivery days
See also:
Creating delivery slot rules
Generating delivery slots
Live delivery slots