Tiffani:
You are correct in your finding that you are allowed "early entry" into the parks at Disney World if you stay on Disney property or at either the Swan & Dolphin, the Hilton at Downtown Disney or at Shades of Green. This feature is called
Extra Magic Hours and vary according to park, time (extra hours in the morning or at night), and day of the week. Currently, Disney World does not offer Extra Magic Hours based on the number of days on your ticket.
It's difficult to predict too far in advance when and where Extra Magic Hours will occur at Disney World, but currently, Morning Magic Hours are at Animal Kingdom on Sundays, Epcot on Tuesdays, Magic Kingdom on Thursdays, and Disney's Hollywood Studios on Saturdays. Evening Magic Hours are at Disney's Hollywood Studios on Mondays, Epcot on Fridays, and Magic Kingdom on Saturdays. However, check the Disney World
calendar for your exact travel dates before planning.
Wishing y'all a magical vacation!
Whitney