Lately we go every year at "Thanksgiving"; we've been in the parks on Saturday, Sunday, Monday, Tuesday before Thanksgiving (our kids out of school) and we've been in the parks Friday, Saturday, Sunday, Monday after Thanksgiving (our kids having to miss 2 days of school). We won't do the days before again, unless we just have no choice -- all those days were REALLY busy, but we found only Friday and Saturday after to be horribly busy -- Sunday after not too bad, and Monday after just wonderful! Of course, I know OP only asked about the days before, but thought I'd thrown in our experience on both sides of Thanksgiving!