NIGHT TIME!!

[ArkhamNative]

I don't think Eorzea contains weeks as we know them

I disagree. You just quoted the part of the tomes that says a moon/month lasts 4 cycles of 8 days. It seems clear that the concept of weeks exists, at least as much as on Earth where we also don't give them names but define how many days long they are.

It's nice to see one of the interpretations of all that from v1, but ultimately it didn't have any detectable influence on anything. So far nobody has seen time pass in ARR. I'd much rather see SE change time/lore/elements to make it all logical and useful than stick with the old system of ambiguities and impotence.