Metonic
/mɪˈtɒnɪk/adjective
Belonging to the nineteen-year cycle after which the phases of the moon fall on the same calendar dates.
The Greek roots
Literally: “of Meton”
The story of the word
Meton of Athens announced in 432 BC that nineteen solar years come to almost exactly 235 lunar months, and the fit is close enough that the error is about two hours. Lunisolar calendars have run on it ever since, from the Hebrew calendar's seven leap months in nineteen years to the church's tables for Easter. Aristophanes put Meton on stage in The Birds as a surveyor with instruments, chased out of the new city before he can lay out a single street.
- How it travelled
- Ancient Greek → English
In a sentence
Nineteen years on, the full moon lands on your birthday again, courtesy of the Metonic cycle.
The gilded number on a church calendar marks the year's place in the Metonic cycle.