A Frontier Airlines sale on fall flights, dubbed "You  snooze, you loose," ends at 11:59 our time tonight.  Tickets must be purchased by 11:59 p.m. Eastern time today for travel Aug. 15 through Nov. 17, 2011. A 14-day advance purchase is required and blackout dates of Sept. 1, 2 and 5 apply. For the deals, click here.