I think they might be adjusting the days as free dining packages "fill up." When originally planning, FD was 10/1-10/8; figured fine, we'd go to WDW late on Friday 10/7, stay at the airport in a priceline hotel, and check in for FD early on 10/8. When I went to make the ressie for 10/8 check in, the online booking program showed all resorts, all levels w/free dining sold out. YIKES!! When I checked room only, there was ample availability. I decided to let a TA handle the ressie and contacted DU, for check in on 10/7. They made the ressie and put a 48 hour courtesy hold on it, so I could transfer rewards money to my Disney VISA rewards card (knocked $700 off the price!). Good thing, because the NEXT day the free dining end date was 10/6! That wouldn't have worked AT ALL as we all have to work here in Maine on 10/7. I checked online and there was plenty of room-only for 10/7, but no free dining. However, I had the courtesy hold on my ressie so I BOOKED IT!!
As they say, the number of rooms available for this special deal is limited!