Chinese Calendar System

The Gregorian Calendar
The modern day internationally recognized calendar system is called the Gregorian calendar system, which started around 1582 to mark the months and years after the birth of Christ. Modern day Chinese too use this Gregorian calendar system which is called GongLi 公历 in Chinese, to be on par with the rest of the world. This calendar system is based on the Western astronomical calculation of solar dates.

But the Chinese have two calendar systems: one is based on solar dates, which is very similar to the Gregorian calendar system and the other is the lunar calendar system. Both of these are mandatory systems in the study and practical application of Chinese Metaphysics such as YiJing, FengShui, BaZi and Date selection.

The Chinese Calendar

The Chinese calendar system is called NongLi 农历 or agricultural calendar. Other terms for it are:

1. XiaLi夏历 or Xia Calendar, so named because it was officially in use during the Xia Dynasty;

2.  YinLi 阴历; it is called YinLi because it incorporates the Moon phases or waxing and waning of the Moon to determine the days;

3.  JiuLi 旧历; it is also called JiuLi because it was an ancient calendar system as compared to the Gregorian calendar system.

The Chinese calendar system incorporates two different time systems: Solar dates and Lunar dates. The Solar dates measure the Earth’s position in relation to the Sun during its orbit around it. The main indicators are the 24 JieQi (Seasons).

The Lunar dates follow the waxing and waning of the Moon’s cycles. Due to this waxing and waning of the Moon, (朔望月caused by the orbit of the Moon around the Earth) there are big months of 30 days and small months of 29 days. This discrepancy in relation to solar dates is the cause for the creation of Leap Months, called RunYue 闰月 in Chinese.

The Chinese calendar system is a system of time measurement based on the combination of Heavenly and Earthly Qi. The Heavenly Qi is represented by the Heavenly Stems and the Earthly Qi is represented by the Earthly Branches.

This system of Stems and Branches, 10 Heavenly Stems and 12 Earthly Branches, when combined is a systematic way, Yang with Yang and Yin with Yin, forms 60 pairs of Stems and Branches, variously called: 60 GanZhi (干支 stem-branch) or 60 JiaZi or 60 Hua JiaZi or the Sexagenary cycle.

The JiaZi system will be discussed in detail in the chapter on Stems and Branches.

History
Presently, the generally accepted historical account is that the Chinese calendar system was invented by the legendary Father of the Chinese people, the first Emperor of China, HuangDi, also called the Yellow Emperor, circa 2697-2599 BC.  

If, according to this assumption, the Chinese calendar 60-year Sexagenary cycle started during HuangDi's time (circa 2697 BC), then the current cycle that started in 1984 should be the 79^th cycle. (79 x 60 = 4740 years.)

There are some historians and authors, such as Herbert A. Giles (A Chinese-English Dictionary 1912) who believed that the beginning of the first cycle was in 2637 BC. If that were the case, then it would mean that the current cycle is the 78^th.   (78 x 60 = 4680 years.)

The Chinese calendar system was originally named XiaLi 夏历 because it was officially in use during the Xia Dynasty. But the name was officially changed to NongLi 农历 or Agricultural Calendar in 1968 during the Chinese Cultural revolution. It was supposedly called NongLi to reflect the agricultural seasons as the calendar system does have a Solar Time system that marks the 24 JieQi (seasons.).

Time Measurement

The GanZhi system measures Time in the Chinese calendar system and encompasses hours, days, months and years. 

The cycles of the 12 years, the 12 months and the 12 double hours are based on the 12 Earthly Branches, and they are combined with Heavenly Stems to denote:

a.  for years – the yearly cycles that coincide with TaiSui

b. for months – the seasons

c.  for days – the days of the month in relation to the waxing and waning of the Moon

d.  for hours – the time of day – morning, noon or night.

Excerpted from Chapter 3 of my book Chinese Metaphysics:Essential FengShui Basics