## Metonic cycle |

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For **Metonic cycle** or **Enneadecaeteris** (from

Considering a year to be ^{1}⁄_{19} of this 6,940-day cycle gives a year length of 365 + ^{1}⁄_{4} + ^{1}⁄_{76} days (the unrounded cycle is much more accurate), which is about 11 days more than 12 synodic months. To keep a 12-month lunar year in pace with the solar year, an

The cycle was used in the *i.e.*, the calculation of the date of

- mathematical basis
- application in traditional calendars
- further details
- see also
- references
- external links

At the time of Meton,

- 19
tropical years = 6,939.602 days (12 × 354-day years + 7 × 384-day years + 3.6 days). - 235
synodic months (lunar phases) = 6,939.688 days (Metonic period by definition). - 254
sidereal months (lunar orbits) = 6,939.702 days (19 + 235 = 254). - 255
draconic months (lunar nodes) = 6,939.1161 days.

Note that the 19-year cycle is also close (to somewhat more than half a day) to 255 draconic months, so it is also an ^{1}⁄_{5} of a Metonic cycle (47 synodic months, 3.8 years), and it recurs about 20 to 25 cycles.

This cycle seems to be a coincidence. The periods of the Moon's orbit around the Earth and the Earth's orbit around the Sun are believed to be independent, and not to have any known physical

A *embolismic*) month needs to be inserted (

Other Languages

العربية: دورة ميتونية

беларуская: Метонаў цыкл

català: Cicle metònic

Deutsch: Meton-Zyklus

Ελληνικά: Μετωνικός κύκλος

español: Ciclo metónico

فارسی: دوره متونی

français: Cycle métonique

galego: Ciclo metónico

한국어: 메톤 주기

հայերեն: Մետոնի ցիկլ

italiano: Ciclo metonico

עברית: מחזור מטון

magyar: Metón-ciklus

Nederlands: Cyclus van Meton

日本語: メトン周期

norsk: Gyldentall

norsk nynorsk: Meton-syklus

polski: Cykl Metona

português: Ciclo metónico

русский: Метонов цикл

shqip: Kalendari i Metonit

Simple English: Metonic cycle

slovenčina: Metónov cyklus

srpskohrvatski / српскохрватски: Metonski ciklus

suomi: Metonin jakso

svenska: Metons cykel

ไทย: วัฏจักรเมตอน

Türkçe: Meton döngüsü

українська: Метонів цикл

Tiếng Việt: Chu kỳ Meton

中文: 默冬章