Besides Watopia there are always two other so called guest worlds available for you to select and ride on. However they will rotate every few days.
So make sure you check the guest world schedule in-game or here 🙂
Watopia is available every day and does not rotate.
Please note that the guest world changeover times are most likely not at 12pm in your local time zone. Changeover time will happen at midnight Eastern Daylight Time.
For example that’s 9 pm in Los Angeles (USA) and 6 am in Amsterdam (Netherlands), so make sure you check your local changeover window.