Is there a year 0 in the AC/BC dating system?

[All-Seeing Aye]

Sort of a random question but couldn't find a definitive answer anywhere; apologies if this has been covered previously.

The graphic on the Years after Aegon's Conquest page shows a year 0 between 1 BC and 1 BC (http://awoiaf.westeros.org/index.php/File:Chronology.png).  In our own system of BC/AD or BCE/CE, there is no year 0.  TWOIAF established the BC/AC labeling which superseded the BL/AL nomenclature (previously used unofficially in the fandom).  It's also important to distinguish between the Landing (in 2 BC) and the Conquest, which apparently was concluded with his coronation in 1 AC.

This could affect the calculations for the ages of Aegon, Rhaenys, and Visenya, the length of the War of the Conquest (2 BC-1 AC, so either ~3 or just 'more than' 2 years depending on the presence of a year 0), and the length of Aegon's own reign.

Any thoughts?

[Lord Varys]

No, there is no year 0. The Conquest began in 2 BC and ended with the coronation of Aegon the Conqueror at the Starry Sept of Oldtown, after which the year 1 AC began. Presumably the day of Aegon's coronation is the first day of the new year.

[All-Seeing Aye]

37 minutes ago, Lord Varys said:

No, there is no year 0. The Conquest began in 2 BC and ended with the coronation of Aegon the Conqueror at the Starry Sept of Oldtown, after which the year 1 AC began. Presumably the day of Aegon's coronation is the first day of the new year.

Right.  But nothing in there technically precludes having a year 0.  I agree that it seems there is no year 0, if only because the term 0 AC/BC is never used in TWOIAF.

So without a year 0 is Aegon's reign, 1 AC-37 AC, 36 years (37-1) or 37 years?

The nomenclature is also somewhat misleading in general because 1 AC, nominally 1 year 'after the Conquest', is actually the endpoint of the Conquest.  BL/AL actually made a lot more sense as a dating system because it was tied to a specific event (the landing at the mouth of the Blackwater in 2 BC) as opposed to a multiyear event (the War of Conquest).

[Wrl6199]

1 minute ago, All-Seeing Aye said:

Right.  But nothing in there technically precludes having a year 0.  I agree that it seems there is no year 0, if only because the term 0 AC/BC is never used in TWOIAF.

So without a year 0 is Aegon's reign, 1 AC-37 AC, 36 years (37-1) or 37 years?

The nomenclature is also somewhat misleading in general because 1 AC, nominally 1 year 'after the Conquest', is actually the endpoint of the Conquest.  BL/AL actually made a lot more sense as a dating system because it was tied to a specific event (the landing at the mouth of the Blackwater in 2 BC) as opposed to a multiyear event (the War of Conquest).

Its sort of like Before Christ and after Christ there was no real year zero there either.

[Lord Varys]

Just now, All-Seeing Aye said:

Right.  But nothing in there technically precludes having a year 0.  I agree that it seems there is no year 0, if only because the term 0 AC/BC is never used in TWOIAF.

But we know the Conquest was a war that took two years. It began in 2 BC, and ended with the coronation at Oldtown, which most likely heralded the beginning of the new year, the first year 'after Aegon's Conquest' (1 AC). Whether they had to change the calendar or whether the coronation fell on the first day of the regular new year as per the established Andal calendar we don't know.

Just now, All-Seeing Aye said:

So without a year 0 is Aegon's reign, 1 AC-37 AC, 36 years (37-1) or 37 years?

Aegon I ruled 37 years (or rather, into his 37 year, we don't know when exactly in 37 AC he died) after the Conquest. If you also want to count the years since his landing into the years of his reign (say, from the beginning of his battle coronation) then he ruled about 39 years, from 2 BC until 37 AC.

Just now, All-Seeing Aye said:

The nomenclature is also somewhat misleading in general because 1 AC, nominally 1 year 'after the Conquest', is actually the endpoint of the Conquest.  BL/AL actually made a lot more sense as a dating system because it was tied to a specific event (the landing at the mouth of the Blackwater in 2 BC) as opposed to a multiyear event (the War of Conquest).

The Conquest formally ended at Oldtown, with the coronation. Thus it actually makes sense to reckon the years thereafter as 'after the Conquest' considering that a conquest is a process that is finished when the conquest is over. George could also have gone with the reckoning after Aegon's Landing but probably changed that because the people of Westeros would have considered Aegon's Conquest and his big coronation a much more important date than the moment of his landing (although the latter date was also celebrated as a holiday by the Targaryen kings).

After all, the end of the conquest and the formal coronation mark Aegon's rise to supreme power, not his landing with a bunch of followers.

[The hairy bear]

There's not a year 0 in any Western calendar. There's never been a "year zero" after the conquest of Rome, the rule of any king, or the AD era. This is because the counting of the years was kept using ordinals (1st, 2nd, 3rd,..), not cardinals (0,1,2,..).