I want to close my hotel's availability for a specific period

Add a Closed Hotel restriction as well

In order to close availability for a specific date or period, you can easily do it by updating your availability to zero (0) either on the availability calendar or by a mass update.

However, you need to have in mind that if you simply turn your availability to zero (0), in case of a cancellation, this availability will change to one (1), so your hotel will be bookable again.

If you want to completely close the availability of your hotel and not be able to receive any new reservations, no matter the cancellations that you may have, then you must Add a Closed Dates restriction. You can update restrictions either for specific dates or massively for a whole period.

After setting your Close Date restrictions, make sure to update the channels by using the respective functionality.