Chinese New Year is the main holiday of the year for more than one quarter of the world's population. Although the People's Republic of China uses the Gregorian calendar for civil purposes, a special Chinese calendar is used for determining festivals. Various Chinese communities around the world also use this calendar. At right, a large dragon lantern glows at a festival for Chinese New Year at the Chiang Kai-shek Memorial. Taipei, Taiwan.

The beginnings of the Chinese calendar can be traced back to the 14th century B.C.E. Legend has it that the Emperor Huangdi invented the calendar in 2637 B.C.E.

The Chinese calendar is based on exact astronomical observations of the longitude of the sun and the phases of the moon. This means that principles of modern science have had an impact on the Chinese calendar.

Chinese Year

The Chinese calendar - like the Hebrew - is a combined solar/lunar calendar in that it strives to have its years coincide with the tropical year and its months coincide with the synodic months. It is not surprising that a few similarities exist between the Chinese and the Hebrew calendar:

An ordinary year has 12 months, a leap year has 13 months.
An ordinary year has 353, 354, or 355 days, a leap year has 383, 384, or 385 days.
When determining what a Chinese year looks like, one must make a number of astronomical calculations:

First, determine the dates for the new moons. Here, a new moon is the completely “black” moon (that is, when the moon is in conjunction with the sun), not the first visible crescent used in the Islamic and Hebrew calendars. The date of a new moon is the first day of a new month.

Secondly, determine the dates when the sun’s longitude is a multiple of 30 degrees. (The sun’s longitude is 0 at Vernal Equinox, 90 at Summer Solstice, 180 at Autumnal Equinox, and 270 at Winter Solstice.) These dates are called the Principal Terms and are used to determine the number of each month:

Principal Term 1 occurs when the sun’s longitude is 330 degrees.
Principal Term 2 occurs when the sun’s longitude is 0 degrees.
Principal Term 3 occurs when the sun’s longitude is 30 degrees.etc.
Principal Term 11 occurs when the sun’s longitude is 270 degrees.
Principal Term 12 occurs when the sun’s longitude is 300 degrees.
Each month carries the number of the Principal Term that occurs in that month.

In rare cases, a month may contain two Principal Terms; in this case the months numbers may have to be shifted. Principal Term 11 (Winter Solstice) must always fall in the 11th month.

All the astronomical calculations are carried out for the meridian 120 degrees east of Greenwich. This roughly corresponds to the east coast of China.

Some variations in these rules are seen in various Chinese communities.

Leap Years

Leap years have 13 months. To determine if a year is a leap year, calculate the number of new moons between the 11th month in one year (i.e., the month containing the Winter Solstice) and the 11th month in the following year. If there are 13 months from the start of the 11th month in the first year to the start of the 11th month in the second year, a leap month must be inserted.

In leap years, at least one month does not contain a Principal Term. The first such month is the leap month. It carries the same number as the previous month, with the additional note that it is the leap month.

How Does One Count Years?

Unlike most other calendars, the Chinese calendar does not count years in an infinite sequence. Instead years have names that are repeated every 60 years.

(Historically, years used to be counted since the accession of an emperor, but this was abolished after the 1911 revolution.)

Within each 60-year cycle, each year is assigned name consisting of two components:

The first component is a Celestial Stemm. These words have no English equivalent:

1. jia
2. yi
3. bing
4. ding
5. wu
6. ji
7. geng
8. xin
9. ren
10. gui

The second component is a Terrestrial Branch. The names of the corresponding animals in the zodiac cycle of 12 animals are given in parentheses.

1. zi (rat)
2. chou (ox)
3. yin (tiger)
4. mao (hare, rabbit)
5. chen (dragon)
6. si (snake)
7. wu (horse)
8. wei (sheep)
9. shen (monkey)
10. you (rooster)
11. xu (dog)
12. hai (pig)

Each of the two components is used sequentially. Thus, the 1st year of the 60-year cycle becomes jia-zi, the 2nd year is yi-chou, the 3rd year is bing-yin, etc. When we reach the end of a component, we start from the beginning: 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 Terrestrial Branch). Finally, the 60th year becomes gui-hai.

This way of naming years within a 60-year cycle goes back approximately 2000 years. A similar naming of days and months has fallen into disuse, but the date name is still listed in calendars.

It is customary to number the 60-year cycles since 2637 B.C.E., when the calendar was supposedly invented. In that year the first 60-year cycle started.

Current Year in the Chinese Calendar

The current 60-year cycle started on 2 Feb 1984. That date bears the name bing-yin in the 60-day cycle, and the first month of that first year bears the name gui-chou in the 60-month cycle.

This means that the year wu-yin, the 15th year in the 78th cycle, started on 28 Jan 1998.

The following are dates for Chinese/Lunar New Year’s day:

4693 Boar January 31, 1995
4694 Rat February 19, 1996
4695 Ox February 7, 1997
4696 Tiger January 28, 1998
4697 Hare/Rabbit February 16, 1999
4698 Dragon February 5, 2000
4699 Snake January 24, 2001
4700 Horse February 12, 2002
4701 Ram/Sheep February 1, 2003
4702 Monkey January 22, 2004
4703 Rooster February 9, 2005
4704 Dog January 29, 2006
4705 Boar February 18, 2007
4706 Rat February 7, 2008
4707 Ox January 26, 2009
4708 Tiger February 10, 2010
4709 Hare/Rabbit February 3, 2011
4710 Dragon January 23, 2012
4711 Snake February 10, 2013
4712 Horse January 31, 2014
4713 Ram/Sheep February 19, 2015
4714 Monkey February 9, 2016
4715 Rooster January 28, 2017
4716 Dog February 16, 2018
4717 Boar February 5, 2019
4718 Rat January 25, 2020