Hi Brittany!
Thanks for your question.
Walt Disney World Bus Service buses run approximately 45 minutes before the park opens. On select days, a theme park will have
Extra Magic Hours, where a park will open 1 hour earlier or stay open later on select days. For example, the
Magic Kingdom typically opens at 9:00AM, However, if it is a morning Extra Magic Hours day, the theme park will open an hour earlier (8:00AM-9:00AM). If the day of your reservation(s) falls on a morning Extra Magic Hours for a theme park, then the buses for, say, the Magic Kingdom on that particular day will begin running at 7:15AM. We've had early morning dining reservations at
Cinderella's Royal Table at Magic Kingdom while staying at Disney's Animal Kingdom, and was able to get there (via bus) on-time on an Extra Magic Hours day.
Also, if traveling between September 1 to November 2, 2019, Disney World will be offering
extra, Extra Magic Hours, with some park openings at 7AM (ex: Magic Kingdom) or 6AM (ex: Hollywood Studios) on select days.
Be sure to check your dining reservations with the
theme park hours for those days to ensure you can take advantage of these benefits!
Terry