Didn't think about it until I saw it on a receipt for an item I bought--today's the 22nd, which means if you haven't gotten it already, make sure to play ODST(on the Master Chief Collection) for the Do You Remember How We Met Achievement! If you miss it, you'll have to wait another month!

I'm posting this on both BO's, to spread awareness. Hopefully this will remind some people—I almost missed it myself.