There were several ways that communities in the ancient world reckoned years. One is the number of years since the foundation of a city. Another is by Olympic games, which is a little more complex because games were held every four years. A third is by naming years after leading magistrates, such as consuls or archons. Then, there are also reckonings by regnal years.

Months did exist but also varied in number of months and days per month state by state. The accuracy of calendars varied by how sophisticated they were, and days, sometimes months even, had to be added on occasion to keep the calendar accurate to seasons/ lunar or solar year