Ancient Civilizations of Mexico and Central America

Plate XXIX

The 260 day cycle of the time count, was subdivided into four periods of 65 days and each period was under control of a single god and was associated with one of the cardinal points. Each period of sixty-five days was further divided into five groups of thirteen days for a ceremonial reason. Some authorities have considered that the general form of the Central American calendar originated in the region of the Isthmus of Tehuantepec and spread to the north and to the south. But dependable history in the Mayan area goes back much farther than in the Zapotecan region and renders such a guess extremely hazardous.