If you've played the storyline at all over the past two years, you'd notice plenty of things that indicate time has passed. The most notable being the big glowing ball of death in the sky transitioning slowly from a small moon, to what it is now. The grand companies launched, and over time, recruited us and formed the Alliance once more. There have been posts on the lodestone over the last two years "ICly" from NPCs from the in-game papers, noting these changes as they have been happening.
Time has passed, it would be silly to think that all this has happened and it hasn't.

Using real-world years just makes sense, considering things like the seasonal events coinciding with ours in the real-world (Starlight festival/Christmas, Heavensturn/New Year's, etc).
To me it just seems like SE wants it to be fifteen years since Mor Dhona to now (Dalamud falling). Thus launch would have been 13 years. I'll probably just update my dates as such. Would be nice to get a concrete "this is the current year" out of them, but I don't think it will happen.
