Hi Paul!
Thanks for reaching out to the Moms Panel!
I love taking advantage of
Extra Magic Hours at Disney's
theme parks. Being able to get inside a theme park and get an attraction or two out of the way early is a
huge benefit, and allows my family more time to enjoy the shows and parades the rest of the day.
If you are staying on Disney property, you can arrive
anytime during
Extra Magic Hours. Disney offers both early and evening
Extra Magic Hours. For example, on January 1st, 2020,
Disney's Magic Kingdom park hours will be 9AM-10PM. However, they are offering evening Extra Magic Hours from 10PM-12AM. So long as you have valid park admission for that day, you can arrive at 10PM, 11PM, whatever works for you! You do not need to physically be in the park at the time it begins to enjoy Extra Magic Hours.
Hope this helps. May you have a magical time at Disney!
Terry