Purchase from April 12 through May 3, 2021, 11:59 p.m. Central Time.
Continental U.S., San Juan, Puerto Rico, and international travel valid May 3 through May 26, 2021 and September 7 through November 5, 2021. Travel continental U.S. to/from Hawaii valid May 3 through May 26, 2021 and August 9 through November 5, 2021.
Continental U.S. travel blacked out October 11 and November 1, 2021. Travel to continental U.S. from Hawaii blacked out August 9-15, 2021.
Except as otherwise specified, continental U.S. travel is not valid on Fridays and Sundays. Travel to Ft. Myers/Naples, Ft. Lauderdale, Miami, West Palm Beach, Tampa, Orlando, Sarasota, Pensacola, Panama City, FL, Destin-Fort Walton Beach, FL, Savannah, Myrtle Beach, Steamboat Springs/Hayden, CO, Montrose (Telluride/Crested Butte), CO, Las Vegas, Santa Barbara, and Bozeman is valid only on Sundays through Wednesdays. Travel from Ft. Myers/Naples, Ft. Lauderdale, Miami, West Palm Beach, Tampa, Orlando, Sarasota, Pensacola, Panama City, FL, Destin-Fort Walton Beach, FL, Savannah, Myrtle Beach, Steamboat Springs/Hayden, CO, Montrose (Telluride/Crested Butte), CO, Las Vegas, Santa Barbara, and Bozeman is valid only on Tuesdays through Fridays. Travel between Ft. Myers/Naples, Ft. Lauderdale, Miami, West Palm Beach, Tampa, Orlando, Sarasota, Pensacola, Panama City, FL, Destin-Fort Walton Beach, FL, Savannah, Myrtle Beach, Steamboat Springs/Hayden, CO, Montrose (Telluride/Crested Butte), CO, Las Vegas, Santa Barbara, and Bozeman is valid only on Tuesdays and Wednesdays. Travel continental U.S. to/from Hawaii is valid Monday – Thursday. Travel to/from San Juan, Puerto Rico is valid Monday – Thursday. International travel is valid Monday – Thursday. Travel to Mexico is valid only on Sundays through Wednesdays. Travel from Mexico is valid only on Tuesdays through Fridays.
Check your destination here.

Screenshot — made at Southwest.com on 04/12/2021