You can require more advance notice on your direct website than your PMS sets, without changing the lead times your OTAs use.
How it works. Support can configure the Advance Notice Blocking module so the site’s global window acts as a minimum. Each property’s effective calendar window becomes whichever is larger: its synced PMS value or the site’s global setting. OTA behavior is not affected, and your website greys out the longer window on every listing’s calendar.
Checkout enforcement. Checkout follows the site-wide Validate advance booking hour setting when that field is non-zero. To enforce the window at checkout as well, set this field to the same number of hours.
Getting it set up. This minimum-window configuration is not currently a self-serve module option. Contact support to request it.