You can enter your closed dates into KennelBooker from the 'Closed Dates' settings page.
When adding closed dates into the system, you can specify if the facility is completely closed to pets, i.e. there will be no pets on site for the duration of the holiday!
You can specify that for the period pets can be onsite but check-in/outs will not be permitted during this period.
The checkbox labelled 'Completely Closed' is used to specify which rule will be observed (with the checkbox ticked the facility will be completely closed).
When the customer tries to book online the they will see the message that you have entered.