Hello.
Probably you are having the Booking Calendar Business Medium or higher version and configure availability via season filters.
Please note, at the Booking > Resources > Availability page you can activate or deactivate the availability for specific “Season Filter” for specific booking resources.
You can edit, delete or add new season filters (define dates that will be available or unavailable ) at the Booking > Resources > Filters page.
Watch it in this video guide https://wpbookingcalendar.com/help/booking-calendar-video-season-availability/
If you was asking about something different, please explain more detail and send screenshots of your issue.
Please note, these questions relative to the premium versions, please ask other questions here https://wpbookingcalendar.com/support/ or directly by email https://wpbookingcalendar.com/contact/
This forum is only about support of Booking Calendar Free version.
Thank you.