Here's a little tip from a Disney 'droid.
Monday is when all of the tourist's are usually kicking off their Magic Kingdom vacations and the parks are heavily traffiked, especially the Magic Kingdom and Animal Kingdom.
During this time of the year, we, the residents of Florida rule the World(Disney) on the weekends. Especially EPCOT and the MK. It can get pretty crowded at those two parks, but Animal Kingdom is sometimes wall to wall too. Especially on Saturday. Friday's are a fairly good time because it seems the residents are all at work and the tourists are elsewhere in Orlando or are heading home.
TIP: Buy the "Unoffcial Guide to Walt Disney World" and read it thru. You'll be glad you did.
Also, don't even THINK about going on Washington's B-day, Spring Break(college) or Easter, unless of course, you like waiting in huge lines and being up to your ears in other tourists and/or raucus, rowdy and largely unsupervised school kids. Blechhh! Also, in March, EPCOT brings in a lot of school kiddies on field trips, so be prepared to share the park with thousands of children.
I hope this will help you on your vacation. Enjoy!
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If it's stupid but works, then it isn't stupid!