Rapa Nui calendar
The Rapa Nui calendar was the indigenous lunisolar calendar
A lunisolar calendar is a calendar in many cultures whose date indicates both the moon phase and the time of the solar year. If the solar year is defined as a tropical year then a lunisolar calendar will give an indication of the season; if it is taken as a sidereal year then the calendar will...
of Easter Island
Easter Island is a Polynesian island in the southeastern Pacific Ocean, at the southeasternmost point of the Polynesian triangle. A special territory of Chile that was annexed in 1888, Easter Island is famous for its 887 extant monumental statues, called moai, created by the early Rapanui people...
. It is now obsolete.
AttestationWilliam J. Thomson, paymaster on the USS Mohican
USS Mohican (1883)
The second USS Mohican was a steam sloop of war in the United States Navy. She was named for the Mohican tribe.-Construction:Mohican was laid down by Mare Island Navy Yard, California, 4 September 1872, funded with the repair money allocated for the first ; launched 27 December 1883; sponsored by...
, 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
In lunar calendars, a lunar month is the time between two identical syzygies . There are many variations. In Middle-Eastern and European traditions, the month starts when the young crescent moon becomes first visible at evening after conjunction with the Sun one or two days before that evening...
and of the months of the year:
- The natives reckoned their time, and in fact do so still by moons or months, commencing the year with August, which was, according to the traditions,the time when Hotu-Matua and his followers landed upon the island.
MonthsThomson recorded the months as follows:
|Rapanui name||Meaning||Western equivalent, 1886–1887|
|Tangarouri||part of November|
|Kotuti||November and December|
|Ruti||December and January|
|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; Thompson records the crescent was first visible on November 26.
|Rapanui name||Meaning|| Western
|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|
|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|
|Orongo||first quarter [sic]||December 18|
|Orongo taane||December 19|
|Mauri nui||December 20|
|Marui [sic] kero||December 21|
|Oata||new moon||December 24|
|Kokore tahi||first kokore||December 26|
The three sources we have correspond with each other except for two intercalary
Intercalation 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.- Solar calendars :...
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:
|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|
|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|
|14||rakau||rakau||rakau||x||—||—||hiro|*New moon, full moon, and first and last quarters.
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 Tahitian ‘aore "there is/are not"; here it may mean "without [a name], nameless".http://www.netaxs.com/~trance/mamari.html
AnalysisThe 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:
- Thomson translates Anakena as August and suggests that the year began at that time because Hotu-Matua landed at Anakena in that month, but my informants and Roussel (1869) give Anakena as July.
- We are basing the substitution on the lists by Metraux and Englert (ME:51; HM:310), which are in agreement. Thomson's list is off by one month.
However, Guy 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
Rongorongo is a system of glyphs discovered in the 19th century on Easter Island that appears to be writing or proto-writing. It cannot be read despite numerous attempts at decipherment. Although some calendrical and what might prove to be genealogical information has been identified, not even...
tablets may describe a rule for when to add these days.