Thanks for giving us the translated post from the German forum. With that information, we can conclude that we were living during an Astral Era period before the 1.19 update which would mark the beginning and period of the umbral era. If we take into account about the length of an era to be true, then technically speaking we would have been adventuring during the Sixth Astral Era, which led to the events of Dalamud as the Seventh Umbral Era, followed by what would be the Seventh Astral Era for FFXIV: ARR. Thus we can map out the following time Umbral/Astral Era sequences of Eorzea where Umbral is followed by Astral = Umbral > Astral = U/A...

The Divine Era - Light?: Time of the gods and goddesses
The First Umbral/Astral Era - Wind: The end of the Divine Era and beginning of "humanity"
The Second U/A Era - Lightning
The Third U/A Era - Fire
The Fourth U/A Era - Earth: The destruction of the Allagan Civilization/Empire
The Fifth U/A Era - Ice
The Sixth U/A Era - Water: The great flood that damaged and submerged the land of Eorzea
The Seventh U/A Era - Darkness?: The day Dalamud exploded and Primal Bahamut was released back into the world

Now... If this sequence is correct then we can say that we are living in the Seventh Umbral Era. However, it's odd that the Eras would be in a U/A sequence but the months are in a A/U (Astral > Umbral) sequence. Furthermore, there is still the trailer to be speculated about. If we are living during the Seventh Astral Era, then what has happened to Bahamut and why hasn't Eorzea been destroyed and become a big pile of rubble? Also why is it that Thancred is shown to be in the same place he was during the time Bahamut was soaring through the skies? How religious is this promiscuous bard since the events of Dalamud or if he is at all? What are the details of the time skip/warp spell that Louisoix cast on the fellow chosen adventures and possibly on all the other main characters?