The sexagenary cycle, also known as the Stems-and-Branches or ganzhi, is a cycle of sixty terms used for reckoning time in China and the
East Asian cultural sphere.
 It appears as a means of recording days in the first Chinese written texts, the
oracle bones of the late second millennium BC. Its use to record years began around the middle of the 3rd century BC.
 The cycle and its variations have been an important part of the traditional calendrical systems in Chinese-influenced Asian states and territories, particularly those of
Vietnam, with the old Chinese system still in use in
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 is still used in names of many historical events, such as the Chinese
Xinhai Revolution, the Japanese
Boshin War, and the Korean
Imjin War. It also continues to have a role in contemporary
Chinese astrology and