The Disneyland resort will celebrate Mickey Mouse's Birthday on November 18, 2017:

Quote Originally Posted by Disney Parks & Resorts

... Disneyland Resort will host a celebration cavalcade for Mickey Mouse, featuring some of his special friends and the Disneyland Band, starting at “it’s a small world” and pausing for a special moment at Sleeping Beauty Castle before continuing down Main Street, U.S.A., to Town Square. There will be plenty of chances to sing “Happy Birthday” along the way, and of course, “Happy Birthday, Mickey!” buttons will be distributed to park guests.