There is no guarantee that castmembers will do anything on your special day or event because thousands of guests are celebrating something every day in DW - birthday, anniversary, engagement, wedding, graduation, family reunion, first visit, a life changing experience. At best, wear the birthday button and many castmembers will wish you a happy birthday. Beyond that, if you want something extra at the resort or at a restaurant you will have to plan and pay for it yourself. Pixie dust can happen and you might experience something extra, but it's just as possible that beyond the "Happy Birthday" greetings, there will be nothing.