The Rapa Nui calendar was the indigenous lunisolar calendar of Easter Island. It is now obsolete.
The Rapa Nui calendar was the indigenous lunisolar calendar of Easter Island. It is now obsolete.
William J. Thomson, paymaster on the USS Mohican, spent twelve days on Easter Island from December 19 to 30, 1886. Among the data Thomson collected were the names of the nights of the lunar month and of the months of the year: [1]
Thomson recorded the months as follows:
| Rapanui name | Meaning | Western equivalent, 1886–1887 |
|---|---|---|
| Anekena | August | |
| Hora-iti | little summer | September |
| Hora-nui | big summer | October |
| Tangarouri | part of November | |
| Kotuti | November and December | |
| Ruti | December and January | |
| Koro | January | |
| Tuaharo | February | |
| Tetuupu | March | |
| Tarahao | April | |
| Vaitu-nui | big winter | May |
| Vaitu-poto | short winter | June |
| Maro or Temaro | July |
The month was divided in two, beginning with the new and full moon. Thomson recorded the calendar at the time of his visit to the island as follows. The new moon occurred on November 25 and again on the night of December 24; [2] Thompson records the crescent was first visible on November 26.
| Rapanui name | Meaning | Western equivalent, 1886 |
|---|---|---|
| Kokore tahi | first kokore | November 27 |
| Kokore rua | second kokore | November 28 |
| Kokore toru | third kokore | November 29 |
| Kokore hâ | fourth kokore | November 30 |
| Kokore rima | fifth kokore | December 1 |
| Kokore ono | sixth kokore | December 2 |
| Maharu | first quarter | December 3 |
| Ohua | December 4 | |
| Otua | December 5 | |
| Ohotu | December 6 | |
| Maure | December 7 | |
| Ina-ira | December 8 | |
| Rakau | December 9 | |
| Omotohi | full moon | December 10 |
| Kokore tahi | first kokore | December 11 |
| Kokore rua | second kokore | December 12 |
| Kokore toru | third kokore | December 13 |
| Kokore hâ | fourth kokore | December 14 |
| Kokore rima | fifth kokore | December 15 |
| Tapume | December 16 | |
| Matua | December 17 | |
| Orongo | first quarter [ sic ] | December 18 |
| Orongo taane | December 19 | |
| Mauri nui | December 20 | |
| Marui [ sic ] kero | December 21 | |
| Omutu | December 22 | |
| Tueo | December 23 | |
| Oata | new moon | December 24 |
| Oari | December 25 | |
| Kokore tahi | first kokore | December 26 |
The three sources we have correspond with each other except for two intercalary days (in bold), and the night of the new moon in Englert, which seems to have been confused with one of these. Beginning with (o)ata, the night of the new moon, they are:
| day | Englert | Thomson | Métraux | day | Englert | Thomson | Métraux |
|---|---|---|---|---|---|---|---|
| *1 | oata | oata | ata | *15 | omotohi | omotohi | motohi |
| 2 | ohiro | oari | ari | 16 | kokore tahi | kokore tahi | kokore tahi |
| 3 | kokore tahi | kokore tahi | kokore tahi | 17 | kokore rua | kokore rua | kokore rua |
| 4 | kokore rua | kokore rua | kokore rua | 18 | kokore toru | kokore toru | kokore toru |
| 5 | kokore toru | kokore toru | kokore toru | 19 | kokore hâ | kokore ha | kokore ha |
| 6 | kokore hâ | kokore ha | kokore ha | 20 | kokore rima | kokore rima | kokore rima |
| 7 | kokore rima | kokore rima | kokore rima | 21 | tapume | tapume | tapume |
| 8 | kokore ono | kokore ono | kokore ono | 22 | matua | matua | matua |
| *9 | maharu | maharu | maharu | *23 | orongo | orongo | rongo |
| 10 | ohua | ohua | hua | 24 | orongo taane | orongo tane | rongo tane |
| 11 | otua | otua | atua | 25 | mauri nui | mauri nui | mauri nui |
| x | — | ohotu | hotu | 26 | mauri karo | mauri kero | mauri kero |
| 12 | maure | maure | maure | 27 | omutu | omutu | mutu |
| 13 | ina-ira | ina-ira | ina-ira | 28 | tireo | tireo | tireo |
| 14 | rakau | rakau | rakau | x | — | — | hiro |
The kokore are unnamed (though numbered) nights; tahi, rua, toru, haa, rima, ono are the numerals 1–6. The word kokore is cognate with Hawaiian ‘a‘ole "no" and Maori kahore "no" and Tahitian ‘aore "there is/are not"; here it may mean "without [a name], nameless".
The calendar collected by Thomson is notable in that it contains thirteen months. All other authors mention only twelve, and Métraux and Barthel find fault with Thomson:
However, Guy [5] calculated the dates of the new moon for years 1885 to 1887 and showed that Thomson's list fit the phases of the moon for 1886. He concluded that the ancient Rapanui used a lunisolar calendar with kotuti its embolismic month (AKA "leap month"), and that Thomson chanced to land on Easter Island in a year with a leap month.
The days hotu and hiro appear to be intercalary. A 28-day calendar month needs one to two intercalary days to keep in phase with the 29½-day lunar month. One of the rongorongo tablets may describe a rule for when to add these days. [6]
A calendar is a system of organizing days. This is done by giving names to periods of time, typically days, weeks, months and years. A date is the designation of a single, specific day within such a system. A calendar is also a physical record of such a system. A calendar can also mean a list of planned events, such as a court calendar or a partly or fully chronological list of documents, such as a calendar of wills.
The full moon is the lunar phase when the Moon appears fully illuminated from Earth's perspective. This occurs when Earth is located between the Sun and the Moon. This means that the lunar hemisphere facing Earth – the near side – is completely sunlit and appears as a circular disk. The full moon occurs roughly once a month.
Intercalation or embolism in timekeeping is the insertion of a leap day, week, or month into some calendar years to make the calendar follow the seasons or moon phases. Lunisolar calendars may require intercalations of both days and months.
A leap year is a calendar year that contains an additional day added to keep the calendar year synchronized with the astronomical year or seasonal year. Because astronomical events and seasons do not repeat in a whole number of days, calendars that have a constant number of days in each year will unavoidably drift over time with respect to the event that the year is supposed to track, such as seasons. By inserting an additional day or month into some years, the drift between a civilization's dating system and the physical properties of the Solar System can be corrected. A year that is not a leap year is a common year.
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A lunisolar calendar is a calendar in many cultures, combining lunar calendars and solar calendars. The date of Lunisolar calendars therefore indicates both the Moon phase and the time of the solar year, that is the position of the Sun in the Earth's sky. If the sidereal year is used instead of the solar year, then the calendar will predict the constellation near which the full moon may occur. As with all calendars which divide the year into months there is an additional requirement that the year have a whole number of months. In this case ordinary years consist of twelve months but every second or third year is an embolismic year, which adds a thirteenth intercalary, embolismic, or leap month.
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A solar calendar is a calendar whose dates indicate the season or almost equivalently the apparent position of the Sun relative to the stars. The Gregorian calendar, widely accepted as a standard in the world, is an example of a solar calendar. The main other type of calendar is a lunar calendar, whose months correspond to cycles of Moon phases. The months of the Gregorian calendar do not correspond to cycles of the Moon phase.
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The Coligny calendar is a second century Celtic calendar found in 1897 in Coligny, France. It is a lunisolar calendar with a five-year cycle of 62 months. It has been used to reconstruct the ancient Celtic calendar. The letters on the calendar are Latin and the language is Gaulish.
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Rongorongo is a system of glyphs discovered in the 19th century on Easter Island that appears to be writing or proto-writing. Text C of the rongorongo corpus, also known as Mamari, is one of two dozen surviving rongorongo texts. It contains the Rapa Nui calendar.
There have been numerous attempts to decipher the rongorongo script of Easter Island since its discovery in the late nineteenth century. As with most undeciphered scripts, many of the proposals have been fanciful. Apart from a portion of one tablet which has been shown to deal with a lunar calendar, none of the texts are understood, and even the calendar cannot actually be read. It is not known if rongorongo directly represents the Rapa Nui language – that is, if it is a true writing system – and oral accounts report that experts in one category of tablet were unable to read other tablets, suggesting either that rongorongo is not a unified system, or that it is proto-writing that requires the reader to already know the text. There are three serious obstacles to decipherment, assuming that rongorongo is writing: the small number of remaining texts, comprising only 15,000 legible glyphs; the lack of context in which to interpret the texts, such as illustrations or parallel texts which can be read; and the fact that the modern Rapa Nui language is heavily mixed with Tahitian and is unlikely to closely reflect the language of the tablets—especially if they record a specialized register such as incantations—while the few remaining examples of the old language are heavily restricted in genre and may not correspond well to the tablets either.
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