Were they numbered as we do it now (2017) or was everything in reference to the present (ie 5 days ago, 4 years ago)? did they have a major reference point as our system has (birth of Christ)? Did they have reference points that changed how they counted years? specifically interested in the early Greek through Roman empires.
I'm doing an assignment on a Pliny the Elder passage and became curious. I've never read an ancient text where they cite a specific date, they all seem to be in reference to the present. I know we classify time periods by the types of tools they had, when battles were fought, etc. I have not read many ancient texts, but I've recently started getting into them.
The System Was Created by Dionysius Exiguus from around the Romanian Bulgarian region in the early 500s but wasn’t really used until the 700s/800s when it was adopted by Bede a famous Anglo Saxon scholar. Many other systems were used before this, such as romans dating years from when Rome was created, and some religions, especially Jews counted from the world was supposedly created.
So people did count time before the Common time system but varied depending on where in the world you were and who you were.
The Roman Republic and Empire counted years by consuls. Two consuls were elected every year, and during the Republic they were the chief magistrate and therefore held a lot of power. It was basically the epitome of political ambition for the Roman. Under the Empire the power of the consuls waned significantly, with a lot of their powers being assumed by the emperor, but it was still a very prestigious position, and importantly, two were still chosen per year.
As for the mechanics of dating, inscriptions or writing would refer to a year as 'the year of the consulship of XXX and YYY' or something along those lines.