I had to refresh my screen. It was strange because this morning prior to 6:00 (or I think it was 5:56 when my dates finally opened) 8/12 was greyed out as well, and I was playing with the system yesterday several times searching on 8/12 since it was the latest day available for booking. Then suddenly, I hit refresh again and the dates were available through 8/21, my check out day.