Hi there, Toni!
Your best bet is to visit the
Disney Parks Web site.
On the main page, you'll find a tab called "Parks and Destinations", which will get you on the path to the Walt Disney World Parks. Simply click on Walt Disney World, and then under Parks and Tickets, choose the Park in which you are interested.
Each Park has a calendar;
the Magic Kingdom calendar, for example, provides a monthly overview, and when you click on each specific date, you'll get hours of operation, event times, and Extra Magic Hours. This is true for each Park.
You can also find hours on third party fan sites, such as AllEars.Net, TouringPlans.Com, and UndercoverTourist.Com.
Have a wonderful trip!
See you later, celebrator,
-Deborah B.