Ancient Lunar Calendar

This is an excerpt from an article I wrote when I was managing editor of a monthly magazine in Hangzhou, China. It was the year 4705-4706 – Earth Rat year. Now twelve years later it is the year 4717- 4718 Metal Rat. The Rat Year begins the 12-year cycle. Let me just say tactfully that the Chinese concept of time is perceptibly different. To paraphrase ancient cartography, beyond this point there be dragons, rats and pigs.

Spring Festival (Chinese Lunar New Year) is calculated according to the Chinese lunar/solar calendar. The total calendar cycle of years goes by the rather spicy name of a sexagenary cycle (60 year cycle). The 60 year Chinese calendar is divided into five twelve year cycles. Each New Year has a zodiac animal name and an elemental name with associated color fire- red, earth-brown, metal-white, water-black and wood-green.

The twelve year calendar cycle is based on the orbit of Jupiter, which is called Suìxīng (the Year Star) in Chinese. Chinese astronomers divided the celestial circle into 12 sections to follow the orbit of Jupiter. Astronomers defined a “year” as the sector (or branch) of sky that Jupiter moved into at a particular time. This system is called the 12 ci (“12 Jupiter stations”). 5 (elements) X 12 (zodiac animals) = 60 years. Five sets of the 12 branches complete the cycle of grand conjunctions of Jupiter with Saturn. Oh yes, every 60 years, Saturn and Jupiter return to their original conjunction and the calendar starts all over again.

This log looked like a loyal dog guardian (I am a dog sign)

I hate to tell you this after we have journeyed so far together, but it is even more complicated, as the entire calendar also incorporates a twenty-four point meteorological cycle which coincides with points 15 degrees apart on the ecliptic (the plane of the Earth’s yearly journey around the Sun, poetically called the Yellow Road). It takes about 15.2 days for the Sun to travel from one of these points to another (because the ecliptic is a complete circle of 360º), and the Sun needs 365.25 days to finish its journey in this cycle.

Each individual day is also divided into 12 double-hour branches, which are identified by one of the zodiac animals. The first double-hour interval begins at 11 P.M. of the previous night; midnight is in the middle, and includes the first hour of the beginning of the day. This period is known as the interval of the Rat. So it is extra lucky at midnight this New Years – the hour of the Rat and the Year of the Rat.

Happy Lunar New Year.