You can set the limit for how far in the future your venue accepts bookings.
Head to Settings >> Booking Restrictions.
You can also use the booking date limit setting to block new public bookings.

You can set the end date to roll over automatically, or fix it at the end of a specified year.
Administrators are not bound by this setting.
By using a date limit, you can add your regular hirers' booking before the general public makes booking requests.
You can choose ‘Block New Bookings’ if you would like to stop the public from making bookings through the system.
See Also
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