Chinese calendar – is lunar/solar. It is based on exact astronomical observations of the sun’s longitude and the moon’s phases. It attempts to have its years coincide with the tropical year and shares some similarities with the Jewish calendar. These similarities are that: an ordinary year has 12 months and a leap year has 13 months; and an ordinary year has 353-355 days while a leap year has 383-385 days.
The Chinese calendar does not count years in an infinite sequence. Each year is assigned a name consisting of two components within each 60-year cycle. The first component is a celestial system based on the five elements/forces: (It also corresponds to aspects of the ancient Bagua)
Jia – associated with growing wood.
Yi – associated with cut timber.
Bing – associated with natural fire.
Ding – associated with artificial fire.
Wu – associated with earth.
Ji – associated with earthenware.
Geng – associated with metal.
Xin – associated with wrought metal.
Ren – associated with running water.
Gui – associated with standing water.
The second component is a terrestrial branch. It features the names of animals in a zodiac cycle consisting of 12 animals, listed below
Zi – rat.
Chou – ox.
Yin – tiger.
Mao – rabbit.
Chen – dragon.
Si – snake.
Wu – horse.
Wei – sheep.
Shen – monkey.
You – rooster.
Xu – dog.
Hai – boar/pig.
Each of the two components is used sequentially. Therefore, the first year of the 60-year cycle becomes jia-zi, the second year is yi-chou, and so on. One starts from the beginning when the end of a component is reached. The 10th year is gui-you, the 11th year is jia-xu (restarting the celestial stem) the 12th year is yi-hai, and the 13th year is bing-zi (restarting the celestial branch). Finally, the 60th year is gui-hai. This pattern of naming years within a 60-year cycle dates back to about 2000 years.
A similar naming of days and months is no longer used but the date name is still listed in calendars. It has been customary to number the 60 year cycle since 2637 BC, when the calendar was supposedly invented.