Sorry I didn't fly last year as we drove. I usually start checking daily, starting in August. These are the dates that I booked our flights over 4 years. Sometimes, I got lucky and was able to book before midnight, when JB had announced the release date was the next day! The worst is when they used to split the release date for March, and you would have to book one flight and then wait for the next release date to book your return flight! Your best tip is to register with TrueBlue and JB will email you with the release dates. Start checking the day before though, as last year they released the flights a day earlier than they had posted!
July 31, 2006 ( this one was really early)
September 21, 2007
September 5, 2008
September 17, 2009