Not sure. Try this out and see if it works.
Type in the date you want to go like this 10/02/2011. Double check if it works that the date is correct. Some people have clicked on a calendar date that was grey, clicked the change search options button or entered a date that Fantasmic isn't shown and it booted them to another date. I would hate for your CC to be charged if it reset the date to tomorrows date.
I booked my ADR using this method when October dates weren't showing up on the calendar back on Apr. 1. I had no trouble getting the time and place I wanted.