Register by September 9 and then travel on Southwest Airlines by November 18, 2021 and you’ll earn a Companion Pass that will be valid January 6, 2022 through February 28, 2022.
That’s two months of companion pass for two one-way flights (that can be a roundtrip, of course). That companion pass means being able to take someone with you on your travels (whether paid or award) for just the cost of security taxes.