To set your advanced availability:
Go to Menu >> Booking System >> Locations & Availability
Click on the location you wish to set advanced availability for
Switch to the availability tab
Set your advanced availability by choosing a time period from the drop down
This controls how far in advance clients can request bookings e.g up to 3 monthsPress save
Note - You will need to set this up on a per location basis to apply to any/all of your locations