A → lunisolar calendar (Chinese: yīnyáng li),
which is now mainly used for determining cultural festivals.
It is based on astronomical observations of the Sun’s annual apparent motion
(→ ecliptic) and → lunar phases.
The calendar starts at Chinese New Year and consists of 12
or 13 → lunar months.
The ecliptic is divided into 24 sections (jiéqi) of 15° each.
In general, Chinese New Year falls on the day of the second
new Moon after the → winter solstice on approximately December 22.
Since 12 months are about 11 days shorter than the → tropical year,
a → leap month is
inserted to keep the calendar in tune with the seasons.
An ordinary → lunar year
has 353-355 days while a → leap year has 383-385 days. Therefore,
the → solstices and → equinoxes move
11 (or 10 or 12) days later. Each 13-month
leap year is about 19 days too long, so the solstices
and equinoxes jump 19 (or 18 or 20) days earlier.
Each year is assigned a name consisting of two
components within a 60-year cycle. The first component is a
celestial stem. The second component is a terrestrial branch; it features the names of
animals in a zodiac cycle consisting of 12 animals.
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 60th year is gui-hai.
The current 60-year cycle started on 2 February 1984.
The leap year must be inserted if there are 13 new moons from
the start of the 11th month in the first year to the start of the 11th
month in the second year.
The beginnings of the Chinese calendar can be traced back to the 14th
century BC. Legend has it that the Emperor Huang-di invented the
calendar in 2637 BC. The calendar has been adopted by several southeast Asian cultures.
The Chinese calendar has undergone several reforms, the last one
in 1645. For more details, see, e.g.,
Helmer Aslaksen, The Mathematics of the Chinese calendar, e-paper.
See also: Chinese adj. of China, from Pers. Cin [Chin], from Qin
the first imperial dynasty of China (221 to 206 BC); → calendar.
