Have you ever heard of the Antikythera Mechanism?

The Antikythera mechanism is an ancient Greek analogue computer used to predict astronomical positions and eclipses for calendar and astrological purposes decades in advance. It could also be used to track the four-year cycle of athletic games which was similar to an Olympiad, the cycle of the ancient Olympic Games.

https://en.wikipedia.org/wiki/Antikythera_mechanism