Secondly, it’s worth noting October 1 is just a huge day in Disney World history. October 1, 1971 was the day the park opened its doors for the first time, which means October 1 of this year marks the parks’ 50th anniversary. Even if a new ride hadn’t been set to open that day, it was going to be a popular day to go to all four major Disney theme parks in Orlando. (Though it is worth noting in 1971, Walt Disney World was just Magic Kingdom. Epcot was added in 1981, Hollywood Studios in 1989 and Animal Kingdom in 1998.) Now, Inside the Magic says Epcot is the second park to fully book up.