And no, there isn't any way to get ADRs for sooner than the 180 days out...other then when you buy a party ticket.
As DaisyDuck said....the 180 day rule is 180 days from your checkin date. Then, you can book all your ADRs for the rest of your stay, up to 10 days, at the same time. It used to be that you had to call each day...it was 180 days from the day you wanted to ADR...that was a huge pain in the neck..if you stayed on-site for a week, you had to call Disney Dining every single day for a week. This system is so much better but it seems confusing to those who are new to it.