They ask that you call the restaurant directly the day before you go, to confirm. Otherwise, they'll call you. Actually, just as long as you call to confirm, the exact day won't make much of a difference. We always eat at V&A on Monday nite. I call to confirm at some point on Sunday. Won't matter what timeyou call--it's an answering machine most times anyway. All they need is your ressie# and a simple statement that your still coming!!
You can just call the Grand Floridian and they'll connect you right to V&A.