90 days out.
And be ready to call at 7am -- I don't know if they are all like this but I tried to get an Illuminations cruise last year and I couldn't get through for 3 mornings. Luckily at that trip we were staying concierge so I finally gave up and asked them to help me get it and they did. But in my experience it was tougher to get than breakfast at the castle!!!!