Croach is correct.
The point is that on the 180 day of your first ADR date you can make up to 10 days of reservations, if you'll be staying there 10 days. It's quite confusing, really.
In the past, you had to call 90 days out for every single day of your trip to get your reservation - so you called 6-7 days in a row for your reservations. To avoid that, you can now call on your first 180 days out and make all your reservations in one sitting up to 10 days in advance. They say 10 days because there are families that stay for 2-3 week vacations so they can't make 30 days worth at a time; just 10.
So call on the 180 day before your very first reservation and make ALL your reservations for your trip in that phone call.