You can actually book up to 30 days doing an online reservation, and more if you call MS, but your designated departure date can never be more than 11 months plus 7 days from the date you make the reservation for your home resort or 7 months plus 7 days for another
DVC resort. Example: if you went online today, Feb 18, 2022, to book your home resort for November 2022, you could book the whole month, assuming availability, but you cannot today book any trip (online or by calling) that ends later than Jan 25, 2023.
When you want more than 7 nights when booking exactly 11 (or 7) months out, the solution is to book 7 nights, and then modify the reservation thereafter to get your total trip, e.g., you could book Jan 18-25, 2023, today, and then tomorrow modify the reservation online by adding the night of Jan 25 by changing your departure date to Jan 26, 2023.