It would interesting to make this confusion an in-character deal, with historians unable to decide if the Calamity was a big deal but not enough to warrant a change of eras (since Bahamut didn't last very long), or if it really was big enough that it is now the Seventh Umbral Era, or even if it's the Seventh Astral because 'obviously' the Umbral one only lasted as long as Bahamut.
Even more fun can be had with different organizations using their own dating. A shipping record from the Limsan docks might read as if it's the Seventh Astral Era, while records in Ul'dah detailing the same shipments date them as if it was still the Sixth. Lots of confused fun can be had! At least until Word of God says what the denizens of Eorzea are using at large.
Even more fun can be had with different organizations using their own dating. A shipping record from the Limsan docks might read as if it's the Seventh Astral Era, while records in Ul'dah detailing the same shipments date them as if it was still the Sixth. Lots of confused fun can be had! At least until Word of God says what the denizens of Eorzea are using at large.