sexagenary cycle

The Chinese sexagenary cycle is a cyclic numeral system of 60 combinations of the two basic cycles, the ten Heavenly Stems (天干; tiāngān) and the twelve Earthly Branches (地支; dìzhī). These have been traditionally used as a means of numbering days and years, not only in China but also in other East Asian nations like Japan, Korea, and Vietnam. It is also an important part of Chinese astrology.
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