It is common to require advance notice for reservations. For example, if an item can only be booked up to a week ahead of time.
Rules such as advance notice are configured per Resource from the Resources option in the Application Management menu item. Within the Access section there are options to require advance notice for new reservations, updates to existing reservations, or deletion of existing reservations.
Updating the advance notice time for any of those three reservation activities will force people to book at least that far in advance.
Application Administrators, Schedule Administrators, and Resource Administrators are excluded from most booking rules, including advance notice rules.