No overnite minimum.
Book online using, not FLYAA (or it will be $149.79), but ONLINE in the promo code box.

Had to book like I was coming back the next day to get and hold the fare. (And, then, of course, I had to click on CHOOSE by SCHEDULE and then click on the link to be flexible and view cheaper fares.) Then, I called and had them change the return for me for that same day - NO OVERNITE (I've learned).

It might work for you, but I couldn't get the fare to work online, doing it myself, to come home the same day. By booking and holding the reservation online, then calling after to fix it, experience has shown that I will still get those online booking bonuses as if I did it myself.

[This message has been edited by lisamcgu (edited 11-28-2001).]