You essentially earn Bonvoy status for the following calendar year, not two years and not based on some rolling qualification or joining date (as some overseas airline programs do). As a courtesy, you also get to enjoy your status benefits as soon as they are earned (for the remainder of the calendar year in which status is earned) plus two additional months (January and February), at the beginning of the year after the full status year, in order to allow late stays to post and to give customers a chance to correct errors. In essence, this means that if you earn status in late December the status lasts for a little over fourteen months, but if you earn status in January, it lasts for about twenty-five months.