See:

http://www.southwest.com/?int=GNAVHOMELOGO

Available only on southwest.com or swabiz.com.

Purchase from Feb. 5 through Feb. 7, 2013, 11:59 pm for the respective time zone of the originating city.

Travel Apr. 3 through June 8, 2013.

Blackout Dates Apply: Boston, Providence, and Manchester: Apr 12-13, Apr 15-16. System blackouts include May 10, 17, 23-24, 27-28.

Travel valid every day except Sundays.

Based on nonstop flights. Select markets. Exclusions and restrictions apply.

Some flights operated by AirTran Airways. Available on published, scheduled service only.

Service to Branson, Missouri begins on March 9, 2013.

Displayed prices include all government taxes and fees.

Seats are limited. Fares may vary by destinations, flight, and day of week and won't be available on some flights that operate during very busy travel times and holiday periods.

Fares are available for one-way travel.

Fares may be combined with other Southwest Airlines combinable fares. If combining with other fares, the most restrictive fare's rules apply.

Fares are not combinable with Senior Fares.

Just booked my late May trip.