Published August 13, 2026 at 2:35 PM HST

The Hawaiian lunar calendar, or kaulana mahina, was a critical way of life on the islands for thousands of years. Communities followed the cycles of the moon to guide their planting and fishing strategies — but Hawaiʻi was not alone.

Many island communities across the Pacific formed their own lunar calendars. New research is looking at how Hawaiʻi’s could match up to those of other islands like Rapa Nui, Tahiti, and Tonga.

The differences could shed new light on the history of Polynesian voyagers and even help reconstruct a long-lost language.

Miguel Valério is a researcher at the University of Murcia in Spain. His research in lunar calendars began by studying tablets from Rapa Nui that were written in a dead language known as the Rongorongo script.

Wikimedia Commons

A wooden tablet showing the rongorongo script of Rapa Nui, or Easter Island.

It has long been thought that one of the tablets contained a phonetic excerpt of a lunar calendar. HPR spoke with Valério to learn more.

More information about the research into lunar calendars and what they reveal about the evolution of language can be found here.

This story aired on The Conversation on Aug. 13, 2026. The Conversation airs weekdays at 11 a.m. Jinwook Lee adapted this story for the web.