I don't mean for this to come off as brusque, but if we're trying to agree on a calender the years 1577, 1578, etc do not exist. The numbering of the year resets with every Era conversion. Otherwise we'd have to include previous Eras and we'd likely be in the Year 9000 or so.
On the 11th sun of the 6th Astral Moon in the Year 1572 of the 6th Astral Era (11/11/1572 6AE) the lesser moon Dalamud unleashed Bahamut upon Eorzea, ending the 6th Astral Era and beckoning the next, 7th Umbral Era at the Year 0 (11/12/0000 or 12/11/0000 depending on how you read dates).
The way I've always reasoned this is that from the 6th Astral Moon (November) to the 1st Astral Moon (January 1st) incorporated Year 0 of the 7th Umbral Era and because a society would like to maintain the day of the new year, the 1st sun of the 1st Astral Moon (January 1st) would mark the start of Year 1 of the 7th Umbral Era.
ARR start of play takes place in Year 5 of the 7th Umbral Era (0005 7UE). After completing the 2.0 MSQ, the Grand Company leaders declare the 7th Umbral Era over and that day would start Year 0 of the 7th Astral Era. If you're one of those people who like to RP with time passing as events from 2.1, 2.2, and the soon to launch 2.3 unfold, we're likely now in the 1st Year of the 7th Astral Era (0001 7AE) given our having a New Years celebration in ARR. This would put us at 6 years post-Calamity.
But it's kind of dangerous to get ahead of game time and relate it to real time (IMO) due to the impending release of the first expansion or v3.0 of XIV. Yoshi said in a recent interview with Nova Crystallis that they are planning a 2.0 to 3.0 story change over that is nearly as shocking as the 1.0 to 2.0 change over. A big event like this will probably have a canon date that 3.0 NPCs may refer back to.
To more directly answer the OP's question, I use this little formula to get my characters age: (1572 + 5) - desired age = birth year. If you have an early birth month, such as January and you wish to maintain that it is currently June in game, the formula changes to (1572 + 6) - desired age = birth year.
Hope this helps! ^^
On the 11th sun of the 6th Astral Moon in the Year 1572 of the 6th Astral Era (11/11/1572 6AE) the lesser moon Dalamud unleashed Bahamut upon Eorzea, ending the 6th Astral Era and beckoning the next, 7th Umbral Era at the Year 0 (11/12/0000 or 12/11/0000 depending on how you read dates).
The way I've always reasoned this is that from the 6th Astral Moon (November) to the 1st Astral Moon (January 1st) incorporated Year 0 of the 7th Umbral Era and because a society would like to maintain the day of the new year, the 1st sun of the 1st Astral Moon (January 1st) would mark the start of Year 1 of the 7th Umbral Era.
ARR start of play takes place in Year 5 of the 7th Umbral Era (0005 7UE). After completing the 2.0 MSQ, the Grand Company leaders declare the 7th Umbral Era over and that day would start Year 0 of the 7th Astral Era. If you're one of those people who like to RP with time passing as events from 2.1, 2.2, and the soon to launch 2.3 unfold, we're likely now in the 1st Year of the 7th Astral Era (0001 7AE) given our having a New Years celebration in ARR. This would put us at 6 years post-Calamity.
But it's kind of dangerous to get ahead of game time and relate it to real time (IMO) due to the impending release of the first expansion or v3.0 of XIV. Yoshi said in a recent interview with Nova Crystallis that they are planning a 2.0 to 3.0 story change over that is nearly as shocking as the 1.0 to 2.0 change over. A big event like this will probably have a canon date that 3.0 NPCs may refer back to.
To more directly answer the OP's question, I use this little formula to get my characters age: (1572 + 5) - desired age = birth year. If you have an early birth month, such as January and you wish to maintain that it is currently June in game, the formula changes to (1572 + 6) - desired age = birth year.
Hope this helps! ^^