Disney have announced via D23 that Star Wars: Galaxy's Edge at Hollywood Studios will open August 29, 2019.
It appears they're ahead of schedule as they originally forecasted the opening to be "late fall".
Millennium Falcon: Smugglers Run attraction will open on the opening day of the land, (August 29), however Star Wars: Rise of the Resistance will open later in the year.
Star Wars: Galaxy's Edge will be open during Extra Magic Hours, and Disney have said demand is high and capacity will be limited.
"When Star Wars: Galaxy's Edge opens at Disney’s Hollywood Studios on August 29, guests will need valid theme park admission to visit the land (though a reservation will not be offered or required) and capacity is limited. Star Wars: Galaxy’s Edge will be open during Extra Magic Hours, providing guests staying at select Walt Disney World Resort hotels the opportunity to enjoy extra time at Disney’s Hollywood Studios experiencing select attractions."