I'm just confused because if the battle of carteneau happened in 1572 and the people who were fighting were teleported away and return 5 years later wouldn't that make it the year 1577? What am I missing? or was the whole 5 years thing misinformation that I've heard?
The Battle of Carteneau happened in 1572, you are correct. It was 1572 of the 6th Astral Era.
However, the Calamity that occurred during the battle is such that it caused a new era. It is now the 7th Umbral Era. When we start a new era in Eorzea due to such an event, the years start over at 1. So it is now, in ARR, year 5 of the 7th Umbral Era, not 1577.
Oh okay so the 6th astral era lasted 1572 years? Sorry I'm a bit new to the lore but that cleared up a lot, thanks.