While it's nice of Square Enix to offer seven free days, there is some fine print that may somewhat limit you.

https://na.finalfantasyxiv.com/lodestone/topics/detail/5d8832c15e6c845e8c76b590f7a8acb26d4921da

For example, the moment you log into the game's launcher, your free 7-day period starts, and from that point forward is when your 168 hours begin counting down. In addition, if you have multiple service accounts attached to a single e-mail, like myself, and one of those accounts is active, then your other, inactive accounts do not qualify for this campaign. However, if they're all inactive, then only the first account to log in will receive the benefits.

So, yeah... It's somewhat limiting, but I just thought I'd throw this out there, since someone might be thinking of coming back for the upcoming expansion, and your account has been inactive for more than 30 days.