It’s hard to extrapolate old geographic trends because they are really vague and unclear about how far the umbral calamities extend, why they centre on eorzea (as in why the ascians always design the calamity to have its source ground zero in eorzea) and how other regions define the passing of time if the calamities are basically restricted to eorzea

Like off the top of my head the 4th umbral calamity and the 6th umbral calamity ONLY affected eorzea (the earthquake that ended allag was centred on the crystal tower and the flood that washed away the magii cities didn’t affect the inner sea)

Like does tural or hingashi even acknowledge the calamity system of dates