If you compare it to this timeline here I don't think we can put Ivalice within the 5th Era or even sooner, sadly =/

http://forum.square-enix.com/ffxiv/t...rzean-Timeline. (It seems a bit outdated, but should work)


We know that Ivalice and the Durai Papers are at least 1000 years old, meaning the Lions War is at least as old as the Dragons War, if not older.
We also know that there was no Golmora-Jungle back then.
Let's assume that Jenomis was right and that one of our calamities really created that jungle.
Let's also assume this calamaty destroyed Ivalice, making place for Dalmasca and that it was the 6th calamity of water.
That would mean, that Ivalice and FFT are at least 1500 years ago and take place in the same Era as Mhach and Amdapor.

Of course in theory any of the calamities could have done that. But the next in order, namely the calamity of ice, took place 3000 years ago.
If Ivalice and the Durai Papers are that old, why doesn't Jenomis say that the Durai Papers are over 2000, or even 3000 years old?

Now, if we assume that this is right, than it means, that the story of Ajora (which takes places 1200 years before FFT) is at least 2700 years old and still within the 6th Era as well.

If Ivalice was destroyed by a calamity, the 6th is the only one that really fits in my opinion.

And even if it wasn't destroyed by one, it still doesn't make much sense to put it in the 5th Era or even sooner, due to the long periods of time that have gone since these eras.