Hello,

AeroMexico calculates Qualifying miles (well, kilometers in this case) on any given 12-month period (and only at the end of that calendar month btw, no qualifying on the day you reach 50k (gold) or 80k (plat) kilometers).

I am an AeroMexico Club Premier Platinum an the only complaint that I've had with them is that it took more than 6 moths for the status to show at other airlines (AF and CO come to mind).

Cheers from Mexico City
Christophe

Edit: One more plus of AM is that you get 100% EQKm on almost any fare systemwide plus AM's codeshares (MX, VW, LA). You can also earn Km's on almost all MX flights, but these aren't EQKm's.