AA is gifting all AAdvantage members something as long as you log in to your frequent flyer account between today and 12/16. (Shouldn’t that be an AAcount?) One day passes, upgrades, or extra miles are all possible. To get it, login, navigate to your account, then click promotions.
If you used referral offers for Citi AA cards that weren’t targeted for you, AA may have already given you your present. You’ll know if you can’t log in to your account to claim it, or because they sent you a nice “gift letter” earlier this year. Condolences if this description fits you.