it’s a bit more mechanically complex than that, it can predict moon phases and eclipses for an entire 19-year metonic cycle. the leading theories right now is that it was a prestige job, an expensive gift made by a master craftsman to show off. the clickspring video series linked in the thread is a really interesting look into it, especially since Chris who runs the channel straight up took a break from building the thing for a year to join a research project about the historical context of the mechanism at his local university.