If you owned 1.0 and played it during it's free time, you're a 1.0 vet, which means you received ARR for free.
If you owned 1.0 and played it during it's PAID time, you're a legacy account, which means you received ARR for free, had your name in the credits, and received a Goobbue Mount/Legacy Chocobo Mount amongst other things.
Both require you to pay today.

EDIT: It's only a month if you are a brand new player or tied a PS3 copy to your 1.0 account. All other 1.0 players got charged today since we only had a two week "welcome back" trial and then the very short extension.