William J. Thomson, paymaster on the USS Mohican, spent twelve days on Easter Island from December 19 to 30, 1886.Three sources 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: 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".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.
The
Mamari
Tablet
of
rongorongo
is thought to include the Rapanui calendar. The identified calendrical information starts midway through recto line 6 (bottom center, upside down) and continues to the start of line 9 (top left). Two glyphs completing the purple sequence (ellipsis) are not visible at the start of 7. Blue and pink beaded lozenges ("accounting sets") follow the identified calendar, but their function is unknown.