Sunday folks here. It just works out better that way. We drive down -- if we drove straight, it's about a 15 hr drive. But with 3 kids -- well, you can do the math! So we usually leave on Friday afternoon and pit-stop in S.C., then we would use Sat to go to St. Aug (my mom lived there). That made a nice, easy 2 hr drive on Sunday to WDW -- perfect! BUT.... Note the past tense -- lived -- she moved recently. So no more pit stops in St Aggie!
Because of this (and because of the way room selection is done, too!) we have re-vamped our plans slightly. Now we will drive on Fri to S.C.; then drive straight to WDW on Sat. We will stay Sat. night on cash somewhere, then check in on Sunday a.m. We usually stay for about 10-12 days, so it works out that we only have 2 weekend "points-pillage" days to worry about. THen we check out mid-week or Fri at latest to head back north again.