On January 29th 2006, well over a billion people worldwide will welcome in the Chinese Year of the Dog. The calculation of the New Year in the traditional Chinese calendar is based upon the world's most ancient existing records of astronomical observation. Chinese oracular bones from the Shang dynasty detail an amazingly accurate luni-solar calendar, circa 1800-1200 BCE.
As with other early agricultural societies, the ability to predict changes in the seasons, to know when to plant one's crops, was necessary for the survival and growth of the Chinese population. The earliest known astronomical tools were designed for exactly this purpose; four thousand years ago, a simple, 8' bamboo pole planted in the earth allowed court astronomers to observe changes in its shadow over the course of the year. Noting that the shadow was longest when the sun took its lowest path across the sky, they realized they had a tool with which to mark the winter solstice. As the sun climbed higher, the days gradually grew warmer and daylight lengthened. Having consumed their stored food during the cold winter months, the Chinese had 'eaten the old year'. The New Year began in the warmth of the second new moon, following the winter solstice.
Chinese Astronomers determine solstice
The celebration of the New Year is known as the Spring Festival. As the month of the traditional Chinese calendar is dictated by the lunar cycle, the festival culminates on the full moon, after a two-week period of celebration. According to folklore, fortunes for the year are swayed during this influential period; one is not to sweep for fear of driving out prosperity, nor use a knife lest one introduce discord and strife to the household.
In 104 BCE Chinese astronomers had determined the length of the solar year to an accuracy of 365.2502 days. By 480 CE this was further refined to 365.2428 days, only 52 seconds longer than today's modern value. Astronomers recognized that without a system to balance their lunar year of 354 days (12 lunar cycles of 29.5 days) with their calculations of the solar year, their predictions of seasonal flooding and advantageous harvest dates would grow less and less accurate. To compensate, they introduced an intercalary month every 2-3 years. Unlike the extra day of the Gregorian system, this 'leap month' duplicates its predecessor. If you are lucky, you could therefore end up with two birthdays within two months!
The oldest star charts still in existence are Chinese. Dated 618-906 CE and likely drawing on a much earlier source, the Dunhuang star maps divide the sky in the northern hemisphere into 12 sections, based on the stations of Jupiter.
Jupiter, the 'year star' (sui hsing) takes 12 years to complete its orbit, giving us a 12-year cycle, or the 'Earthly Branch' component of the traditional Chinese calendar. The years are named for the 12 different animals whom, according to tradition, responded to Buddha's call as he departed the terrestrial realm. Each of these years is said to be characterized by the nature of its namesake animal. Together, the 12 years equal one 'Great Year' in the calendar.
- Earthly Branches
- 1. zi (rat)
- 2. chou (ox)
- 3. yin (tiger)
- 4. mao (hare)
- 5. chen (dragon)
- 6. si (snake)
- 7. wu (horse)
- 8. wei (sheep)
- 9. shen (monkey)
- 10. you (rooster)
- 11. xu (dog)
- 12. hai (pig)
To calculate the year according to the traditional Chinese calendar, one employs a sexagenary cycle of the 12 Earthly Branches in connection with 10 Celestial Stems. These ten archaic ideograms are associated with 5 elements: Wood, Fire, Earth, Metal and Water. Each element is further identified as either Yin (receptive, creative, female) or Yang (active, productive, male), bringing the total number of Heavenly Stems to 10.
- Celestial Stems and Associations
- 1. jia (wood, yang)
- 2. yi (wood, yin)
- 3. bing (fire, yang)
- 4. ding (fire, yin)
- 5. wu (earth, yang)
- 6. ji (earth, yin)
- 7. geng (metal, yang)
- 8. xin (metal, yin)
- 9. ren (water, yang)
- 10. gui (water, yin)
As each of the earthly branches can only exist in a yin or yang year (Dragon Year is always yang, Snake is always yin?) a 60-year cycle is created of 5 Great Years. The current cycle began in 1984 with the year of the Wood Rat, heavenly branch jia, earthly stem zi.
|5 Great Years: Celestial Stems
and Earthly Branches of the Current Cycle
When this system was first described, attaining 60 years of age was a remarkable achievement. These 5 Great Years, each characterized by the element associated with its inception, are therefore also used to describe the course of individual existence. The first Great Year of life, from birth to age 12, is an era of growth and physicality, ruled by the element of wood. Fire characterizes the next stage of development, energy and transformation being essential to the emerging adult. From twenty-five to thirty-six, one concerns oneself with the material stability symbolized by earth. As confidence and power solidify in later adulthood, one attains the dominance and mastery of the element metal. Finally, at the ripe old age of 49, one is ready to settle into the quiet reflection symbolized by water.
Although the Chinese calendar was officially replaced with the Gregorian system in 1911, it is still widely consulted for the traditional wisdom it contains. Its usage allows us a brief glimpse into the minds of the world's most ancient, documented astronomers. On January 29th, we'll enter the year of the Fire Dog; bing-xu. Those early sky-watchers would tell us that the industrious, loyal, creative and judicious will be well rewarded in the year to come.
"Gung Hay Fat Choy" is the traditional New Year's greeting in Cantonese, a dialect of Chinese, and literally means "Congratulations and Best Wishes for a Prosperous Year!" In Mandarin, the official Chinese dialect, the literal translation of "Happy New Year!" is pronounced "Xin Nian Kuai Le!"
- New Mexico State University Astronomy Department
Claire is a member of our Starry NightŪ team, whose long-time interest in mythology brings a different perspective to our understanding of the night sky.