Disneyland, California Adventure, open 24 hoursDisney announced that it will keep three of its theme parks open for 24 hours in a row on May 24 to celebrate the start of summer. Disneyland Park and Disney Adventure Park in Anaheim and The Magic Kingdom Park in Orlando will stay open from 6 AM to 6 AM to kick off Memorial Day weekend. Most of the extra bells and whistles in the “All-Nighter” initiative are tied to Disney/Pixar’s prequel Monsters University, which opens in the U.S. on June 21.