This is the furthest date in the future that you want to accept bookings
Manage listings > Calendar > Scroll down to booking cut off date (Set date or choose months from today)
By leaving this date blank you'll have the option to accept a booking at any future date
This means you're taking responsibility to keep your rates up-to-date. (e.g. with a Base Rate set high enough that you won't be disappointed if someone inquires to book a high season date far in the future that you haven't updated)
Example: a guest wants to book a special anniversary in two years when you haven’t set a rate. Please make sure your rates are updated.
You also have an option to set a booking cut off date in months from today.