Southwest Airlines is doing away with its 50-year tradition and plans to start assigning seats, as well as premium seating for customers who are seeking more legroom.

The airline said today that it has been studying customer preferences and expectations and is making the changes because of what they’ve heard, but it could also generate revenue and boost financial performance.

While Southwest has used an open seating model for 50 years, the company said that it understands that preferences have changed, with more customers taking longer flights and wanting an assigned seat.

The airline also said it will offer redeye flights for the first time.

Southwest said that its first overnight, redeye flights will land on Feb. 14, 2025 in nonstop markets that include Las Vegas to Baltimore and Orlando; Los Angeles to Baltimore and Nashville; and Phoenix to Baltimore. It plans to phase in additional redeye flights over time.