Minor WI, the urbe condita calendary remains after the conversion of rome

[Gukpard]

After the roman empire converted to christianity, a lot of the roman customs were christianized, but also the roman church adopted a lot of customs from the roman empire, with that I mind I came here with a idea

What if instead adopting the anno domini callendary, the catholic church kept the Urbe Condita one, in this case we would be in the year 2770 ab, or MMXVII if you prefer. Would this be plausible?

 

[carlton_bach]

It would be unlikely. AUC was always more of an intellectual affectation. For all practical purposes, the Roman Empire (long after Constantine) named the years after the senior (eponymous) consuls while the barbarian kingdoms typically used regnal years. Much later, the Byzantine Empire adopted a dating system from Creation while the papacy embraced the birth of Christ as its calendrical starting point. It spread from there. Without it, though, the church is far more likely to either use pontifical regnal years or adopt the Roman calendar 'after Creation'.

 

[Dathi THorfinnsson]

In addition, "AD" was a latish invention.

This dating system was devised in 525 by Dionysius Exiguus of Scythia Minor, but was not widely used until after 800.[10][11]

As @carlton_bach says, the Byzantine dating is far more likely than AUC.