Last year we went the week of April 24th and the dates released late on December 20th. I am not sure if it had something to do with the SW plane running off the runway in Chicago. For 2007 we are going for the same week and dates released November 20th. I got tickets for the week I wanted, but I was caught off guard and missed Saturday departure (Sunday is not so bad). I thought it would be in December. I highly recommend checking every day to be safe.