"... Whatever may have been the reason for the preëminence of the Pleiades cluster - and it was probably a combination of several reasons - it is certain that when men became increasingly alert to the annual cycles of celestial phenomena, the changing altitudes and azimuths of the Sun, the lengthening and shortening of days and the corresponding variation in temperature, the slow march of the constellations across the sky, and realized the need of choosing a day on which to begin the yearly cycle of the calendar, they turned to the Pleiades for guidance.

Undoubtedly the Polynesians carried the Pleiades year with them into the Pacific from the ancient homeland ... With but few exceptions they continued to date the annual cycle from the rising of these stars until modern times.

In the Hawaiian, Samoan, Tongan, Society, Marquesan, and some other islands the new year began in late November or early December with the first new Moon after the first appearance of the Pleiades in the eastern sky in the evening twilight.

Notable exceptions to the general rule are found in Pukapuka and among certain tribes of New Zealand where the new year was inaugurated by the first new Moon after the Pleiades appeared on the eastern horizon just before sunrise in June. Traces of an ancient year beginning in May have been noted in the Society Islands, but there is some uncertainty about the beginning of the year in native annals generally, at least as reported by missionaries and others, due perhaps to the desire to make the Polynesian months coincide with the stated months of the modern calendar.

In view of the almost universal prevalence of the Pleiades year throughout the Polynesian area it is surprising to find that in the South Island and certain parts of the North Island of New Zealand and in the neighboring Chatham Islands, the year began with the new Moon after the yearly morning [heliacal] rising, not of the Pleiades, but of the star Rigel in Orion. Such an important difference can be explained only on the assumption that the very first settlers ... brought the Rigel year with them ... from some other land 10° south of the equator where Rigel acquired at the same time its synonymity with the zenith.

Colonists who arrived in New Zealand from Central Polynesia during the Middle Ages and intermarried with the tangata whenua, 'people of the land', found themselves between the horns of a calendrical dilemma. They must either convert the aborigines to the Pleiades year beginning in November-December or themselves adopt the Rigel year [together with heliacal rising observations] and bring down the wrath of their ancestors on their own heads.

That there resulted a long and passionate struggle on the part of both the invaders and the invaded to retain their own the integrity of the sacred year of their traditions can hardly by doubted. The outcome of the conflict proved that the institution of the land was too firmly established to be changed. While some tribes retained the Rigel year in its entirety others effected a compromise by retaining the Pleiades year but commencing it in June ..." (Makemson)