Walt Disney Imagineering has announced the "Opening Seasons" for Star Wars: Galaxy's Edge at Walt Disney World and Disneyland:

Quote Originally Posted by Disney Parks & Resorts
... Star Wars: Galaxy’s Edge will open in Summer 2019 at Disneyland Resort and in Late Fall 2019 at Walt Disney World Resort, when guests will land in the middle of the action as they live their own Star Wars stories.
This is timetable that had been rumoured/reported, but it has now been Publicly confirmed.