Southwest Airlines or supposed to extend their schedule yesterday. Then they said that they we would extend it on March 18th. But instead they did so today.
They are currently accepting air reservations through November 2, 2019. On May 23, 2019 they will open the schedule for sale through January 5, 2020.
It’s a good idea to start looking for travel dates early, especially for peak times. With Southwest’s refund policy, there’s not much to worry about. Even if you working towards a Companion Pass but don’t have it yet, you can book now and add a companion later.