The Chinese sexagenary cycle (Chinese: 六十花甲; pinyin: liùshí huājiǎ), also known as the Stems-and-Branches (Chinese: 干支; pinyin: gānzhī), is a cycle of sixty terms used for recording days or years. It appears, as a means of recording days, in the first Chinese written texts, the Shang dynasty oracle bones from the late second millennium BC. Its use to record years began around the middle of the 3rd century B.C. The cycle, and variations on it, have been an important part of historical calendrical systems in other, Chinese-influenced Asian states, notably those of Japan, Korea and Vietnam. This traditional method of numbering days and years no longer has any significant role in modern Chinese time keeping or the official calendar. However, the sexagenary cycle continues to have a role in contemporary Chinese astrology and fortune telling.^{[citation needed]}

Each term in the sexagenary cycle consists of two Chinese characters, the first representing a term from a cycle of ten known as the Heavenly Stems (天干; tiāngān) and the second from a cycle of twelve known as the Earthly Branches (地支; dìzhī). The first term (甲子 jiǎ-zǐ) combines the first heavenly stem (甲; jiǎ) with the first earthly branch (子; zǐ). The second (乙丑; yǐ-chǒu) combines the second stem with the second branch. This continues, generating a total of 60 different terms (the least common multiple of ten and twelve), after which the cycle repeats itself. This combination of two sub-cycles to generate a larger cycle and its use to record time have parallels in other calendrical systems, notably the Akan calendar.