With AA, you qualify during the calendar year (exception: challenges as in the previous post) but your status runs through February two years later. So, if you get 25,000 miles in calendar 2000, you're Gold AAdvantage from the day you qualify through Feb. 28, 2002.

They probably started this schedule so they'd have time after the end of the year to sort out the levels before computers did it all in real time, and have just kept it since.