Video from toldinstone
How Did the Greeks and Romans Count Years?
"The AD/CE system we use to date the year was introduced - more or less by accident - during the Middle Ages. Before its invention, the classical world used a wide range of dating systems.
Chapters: 0:00 Introduction 0:51 Ancient Greek Calendars 1:42 Counting by Olympiads 2:22 The Seleucid Era 2:56 Consular Dating 3:26 Ab Urbe Condita 4:28 Indictions 4:56 Christian Chronology 5:40 Anno Domini 7:00 Conclusion" from video introduction.