Every Earthly year gives us twelve of these lunar cycles (plus some extra days, which we will discuss in a moment). So the Hawaiian system, like the Gregorian, has twelve months, called malama. Each malama follows the moon exactly. The thirty days of each malama are divided into three ten-day anahulu (weeks, so to speak)—one anahulu while the moon is waxing (called ho‘onui, to increase), one during the moon’s fullness (piha poepoe, round fullness), and the third as the moon wanes (ho‘emi, to diminish).
Twelve months times 30 days a month gives us a year of 360 days. Close, but no cigar. This is where the Hawaiians had to solve the mathematical problem of matching the moon’s rhythm to the sun’s seasonal ride through the ever-repeating cycle known as a “year”—which, as we all know, lasts about 365 and one-fourth day.
To resolve this disparity in the Gregorian system, we detach our months from the actual reality of the moon, we stuff them with extra days, then we add a “leap day” every four years (minus three leap days in every four centuries). The Hawaiian system, by contrast, allows for an extra, thirteenth month (called malama pili or malama ‘ukali) to be inserted whenever appropriate.
What’s appropriate depends upon the stars.
And this is where kaulana mahina breaks into sophisticated territory. Kalei Tsuha’s research shows that the Hawaiians devised fourteen different versions of this rogue month, and they would insert the appropriate version depending on variations in the rising of the stars, constellations, and planets. In other words, the kahuna knew when individual stars were supposed to appear on the horizon, and if the stars shifted from what was predicted, the Hawaiians adjusted their calendar—just like navigators trimming their sails on the open sea.