I age alongside RL years.
Using FFXI as a precedent, SE is... kinda bad about how they handle time. Twelve years and six (or seven, if you count Abyssea) expansions later, SE's official stance on why they haven't updated dialogue/text when it comes to dates is that a Vana'diel year has not passed yet... despite holiday event dialogue that contains things like "every year" and "last year" and "remember in years past--"
I also think it's an easier way to keep the people who do keep an actual tally of their years on the same page. If new content/expansions say X-amount of time has suddenly passed when you do Y-event, there's no real way to reconcile or enforce it for people who haven't done that content yet (or don't acknowledge content).
Using FFXI as a precedent, SE is... kinda bad about how they handle time. Twelve years and six (or seven, if you count Abyssea) expansions later, SE's official stance on why they haven't updated dialogue/text when it comes to dates is that a Vana'diel year has not passed yet... despite holiday event dialogue that contains things like "every year" and "last year" and "remember in years past--"
I also think it's an easier way to keep the people who do keep an actual tally of their years on the same page. If new content/expansions say X-amount of time has suddenly passed when you do Y-event, there's no real way to reconcile or enforce it for people who haven't done that content yet (or don't acknowledge content).