I find it hard to believe that this is the actual release date. Apple said Tiger would be released in the first half of 2005, and this date is the midway point of this 6 month timeframe, which is probably why Amazon chose it.
This date is on a Thursday, and as I recall, both Jaguar and Panther were released on a Saturday. I believe Apple held release parties on Friday evenings, and after midnight the OS went on sale. I don't see them holding any special events on a Wednesday evening.