Metonic cycle
E11371
The Metonic cycle is a 19-year astronomical period after which the phases of the Moon recur on the same days of the solar year, forming the basis for many lunisolar calendars.
All labels observed (5)
| Label | Occurrences |
|---|---|
| Metonic cycle canonical | 5 |
| Athenian calendar reform | 1 |
| Attic calendar | 1 |
| Metonic cycle used in later calendar computations | 1 |
| Váḥid (cycle of 19 years) | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T113495 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: Metonic cycle Context triple: [Hebrew calendar, followsCycle, Metonic cycle]
-
A.
Hebrew calendar
The Hebrew calendar is a lunisolar calendar used primarily for Jewish religious observances, holidays, and the determination of ceremonial dates.
-
B.
Paschal cycle
The Paschal cycle is the sequence of movable feasts and liturgical observances in the Christian calendar that are determined each year in relation to the date of Easter.
-
C.
Gregorian calendar (Western churches)
The Gregorian calendar (Western churches) is the internationally used solar dating system introduced in 1582 that most Western Christian churches follow for determining liturgical dates and feasts.
-
D.
Crescent
Crescent is a long-distance Amtrak passenger train that runs between New York City and New Orleans, serving major cities along the U.S. East Coast and Deep South.
-
E.
Labarum
The Labarum is an early Christian military standard bearing the Chi-Rho symbol, famously associated with the Roman emperor Constantine the Great.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: Metonic cycle Target entity description: The Metonic cycle is a 19-year astronomical period after which the phases of the Moon recur on the same days of the solar year, forming the basis for many lunisolar calendars.
-
A.
Hebrew calendar
The Hebrew calendar is a lunisolar calendar used primarily for Jewish religious observances, holidays, and the determination of ceremonial dates.
-
B.
Paschal cycle
The Paschal cycle is the sequence of movable feasts and liturgical observances in the Christian calendar that are determined each year in relation to the date of Easter.
-
C.
Gregorian calendar (Western churches)
The Gregorian calendar (Western churches) is the internationally used solar dating system introduced in 1582 that most Western Christian churches follow for determining liturgical dates and feasts.
-
D.
Crescent
Crescent is a long-distance Amtrak passenger train that runs between New York City and New Orleans, serving major cities along the U.S. East Coast and Deep South.
-
E.
Labarum
The Labarum is an early Christian military standard bearing the Chi-Rho symbol, famously associated with the Roman emperor Constantine the Great.
- F. None of above. chosen
Statements (44)
| Predicate | Object |
|---|---|
| instanceOf |
astronomical cycle
ⓘ
lunar-solar cycle ⓘ |
| appliesTo |
phases of the Moon
ⓘ
solar year ⓘ |
| approximateEquality | 19 tropical years ≈ 235 synodic months ⓘ |
| approximationError |
about 1 day in 219 years
ⓘ
about 2 hours per 19-year cycle ⓘ |
| calendarBasisFor |
19-year Hebrew calendar cycle
ⓘ
distribution of leap months in many lunisolar calendars ⓘ distribution of leap years in Hebrew calendar ⓘ |
| category |
astronomical timekeeping
ⓘ
calendar cycles ⓘ |
| discoveredBy | Meton of Athens ⓘ |
| discoveredInCentury | 5th century BCE ⓘ |
| firstUsedIn | classical Greek astronomy ⓘ |
| hasComponent |
12 common years with 12 lunar months each
ⓘ
7 leap years with 13 lunar months each ⓘ |
| hasDuration |
about 19 years
ⓘ
about 6940 days ⓘ |
| hasPeriod |
19 tropical years
ⓘ
approximately 235 synodic months ⓘ |
| hasProperty |
nearly commensurate lunar and solar periods
ⓘ
phases of Moon recur on nearly same calendar dates after 19 years ⓘ |
| hasTypeOfMonth | synodic month ⓘ |
| hasTypeOfYear | tropical year ⓘ |
| influenced |
medieval calendar calculations
ⓘ
structure of ecclesiastical lunar tables ⓘ |
| isApproximationOf | true relation between lunar months and solar years ⓘ |
| namedAfter | Meton of Athens ⓘ |
| relatedTo |
Callippic cycle
ⓘ
Easter computus ⓘ
linked to:
Paschal cycle
Saros cycle ⓘ |
| totalCommonYears | 12 ⓘ |
| totalLeapYears | 7 ⓘ |
| totalMonths | 235 lunar months ⓘ |
| usedFor |
aligning lunar months with solar year
ⓘ
designing leap-month patterns in lunisolar calendars ⓘ predicting recurrence of lunar phases on same calendar dates ⓘ |
| usedIn |
Babylonian calendar
ⓘ
Hebrew calendar ⓘ ancient Greek lunisolar calendars ⓘ ecclesiastical lunar calculations ⓘ lunisolar calendars ⓘ traditional Chinese calendar ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: Metonic cycle Description of subject: The Metonic cycle is a 19-year astronomical period after which the phases of the Moon recur on the same days of the solar year, forming the basis for many lunisolar calendars.
Referenced by (9)
Full triples — surface form annotated when it differs from this entity's canonical label.
linked to: Metonic cycle
linked to: Metonic cycle
linked to: Metonic cycle
linked to: Metonic cycle