Walt Disney Co. is requiring guests at its Disneyland theme park in Anaheim, Calif., to reserve specific times to visit a new Star Wars attraction as the company looks for ways to manage an expected surge in crowds.

Disney historically hasn’t required guests to make reservations to enter its parks, although it has stepped up efforts in recent years to manage demand, such as introducing a tiered-pricing system that charges visitors more during peak times.

The reservations for the Star Wars themed land won’t cost anything, but will be subject to availability. Guests will also need buy tickets to enter the park, which cost as much as $149 on peak days. Visitors staying at one of Disney’s hotels in California will receive a reservation for that day, and more details on the reservation system will be released at a later date.

The world’s largest theme park operator announced the opening dates Thursday for the two new attractions, dubbed “Star Wars: Galaxy’s Edge.” The one at Disneyland in Anaheim will open May 31, followed by another Aug. 29 at Disney’s Hollywood Studios in Orlando, Fla.

The Disneyland reservations will be required from May 31 to June 23. Dennis Speigel, a theme park consultant in Cincinnati, said Disney may have to extend the reservation period and take other steps to control crowds.

“I don’t think they really know where the upper limits are on demand,” Speigel said.

Disneyland is already the second-most visited theme park in the world, after Disney’s Magic Kingdom in Orlando.

At 14 acres each, the new attractions will be the largest additions to an existing park the company has ever built.

Disney’s Chief Executive Officer Bob Iger announced the openings at the company’s annual meeting Thursday in St. Louis, adding that the dates were a little earlier than originally expected.

“No one has ever attempted anything of this magnitude,” Iger told shareholders Thursday. He said one overarching bit of advice he gave park designers: “Make sure they’re ambitious.”

In a sign of how quickly Disney is moving, one of the attractions, which puts guests in the middle of a battle between the First Order and the Resistance, won’t be open until later this year. On opening day, guests will be able to ride in a model of the Millennium Falcon space ship and participate in other activities such as a build-you-own-droid workshop.