Seleucid era

The Seleucid era or Anno Graecorum (literally "year of the Greeks" or "Greek year") was a system of numbering years in use by the Seleucid Empire and other countries in the ancient Hellenistic civilizations.

There were two different variations. The Seleucids year started in spring. The Macedonian court started the year in autumn. Year 1 of the Seleucid era is roughly to April 311 BC to March 310 BC.