Metonic cycle

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Me·ton·ic cycle

A period of 235 lunar months, or about 19 years in the Julian calendar, at the end of which the phases of the moon recur in the same order and on the same days as in the preceding cycle.

[After Meton (fl. fifth century bc), Athenian astronomer.]
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Metonic cycle

(Astronomy) a cycle of nearly 235 synodic months after which the phases of the moon recur on the same days of the year. See also golden number
[C17: named after Meton, 5th-century bc Athenian astronomer]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
References in periodicals archive ?
According to Loewinger, based on his study of the fixed Hebrew calendar, the 8th year in the 19-year Metonic cycle should not be intercalated, as it is unnecessary.
This is known as the Metonic cycle. So, in other words, the phases of the moon realign (or nearly realign) with the same calendar dates every 19 years." (The right shutter timing may have you catching the silhouette of Santa's sleigh.
In the late 300s, Theophilus published a century-long list of accurate Easter dates based on the 19-year-long Metonic cycle; in the early 400s, Cyrillus published a 110-year-long list.
This points to the Metonic cycle, the well-known period of 19 years after which the lunar phases repeat on (nearly) the same dates of the year.
However, there is a curious relationship between the number of days in a solar year and those in a lunar cycle as given in #1 and #2, respectively, that nevertheless makes a lunar-solar (or lunisolar) calendar possible; this relationship is known as the Metonic cycle.
Another may be to question why the Mishnaic calendar was observationally based, while the Babylonian calendar it supposedly derived from had already evolved into a calculated calendar based on the 19-year Metonic cycle since the fifth century B.C.E.
`In effect, Claudio is saying that a whole age has passed without the enforcement of the law; he is implying the ridiculousness of reawakening a law so long dormant.'(6) Nineteen is not an arbitrary number; rather it may be a reference to the Metonic cycle or period, which is defined by OED as `the cycle of 19 Julian years ...
This September 27th, one Metonic cycle later, a very similar total lunar eclipse will be widely seen during the evening throughout the Americas.