Numeral systems are simply writing systems for expressing numbers. They are often structured procedures or methods for counting so as to determine the total units within a particular collection. One of the numeration systems in China is the Sexagenary Cycle, which we will extensively discuss in this article. Read on to find out more about it.
Sexagenary Meaning
In general, the word ‘sexagenary’ describes something/someone pertaining to the number 60 or something composed of or proceeding by 60s. The sexagenary cycle, which is otherwise known as Ganzhi in China, the 60-year cycle, or the Stems-and-Branches is described as a cycle of 60 terms. It is an ancient counting system which was frequently used to record time in China and other East Asian regions, and it is also referred to as the primary means of recording dates in ancient Chinese literary works.
Each term found in the sexagenary cycle is comprised of two Chinese characters. The first character is one of the ten Heavenly stems of the Shang-era week and the second character is one of the 12 Earthly branches that represent the various years of Jupiter’s cycle around its orbit. The first heavenly stem is paired with the first earthly branch, the second heavenly stem is paired with the second earthly branch, and so on and so forth. However, the last two characters in the 12 earthly braches are paired to the heavenly stems according to their yin and yang properties. Whenever one runs out of the stems and branches, they are to start from the beginning, just as one would when trying to read through time on a clock.
The first table below shows the ten Heavenly Stems and the twelve earthly branches as denoted by the sexagenary cycle.
| Number | Heavenly Stems | Earthly Branches |
| One | Jiǎ (甲) | Zǐ (子) |
| Two | Yǐ (乙) | Chǒu (丑) |
| Three | Bǐng (丙) | Yín (寅) |
| Four | Dīng (丁) | Mǎo (卯) |
| Five | Wù (戊) | Chén (辰) |
| Six | Jǐ (己) | Sì (巳) |
| Seven | Gēng (庚) | Wǔ (午) |
| Eight | Xīn (辛) | Wèi (未) |
| Nine | Rén (壬) | Shēn (申) |
| Ten | Guǐ (癸) | Yǒu (酉) |
| Eleven | Xū (戌) | |
| Twelve | Hài (亥) |
The second table below highlights the 60 numbers which are found within the sexagenary cycle. If you look through the numbers, you will realize that some numbers have the same connotation, which explains how one has to start over from the beginning very time they run out of stems and branches.
| Number | Connotation | Number | Connotation | Number | Connotation | Number | Connotation |
| One | Jiǎ zǐ | Sixteen | Jǐ sì | Thirty-One | Jiǎ zǐ | Forty Six | Jǐ sì |
| Two | Yǐ chǒu | Seventeen | Gēng wǔ | Thirty Two | Yǐ chǒu | Forty Seven | Gēng wǔ |
| Three | Bǐng yín | Eighteen | Xīn wèi | Thirty Three | Bǐng yín | Forty Eight | Xīn wèi |
| Four | Dīng mǎo | Nineteen | Rén shēn | Thirty Four | Dīng mǎo | Forty Nine | Rén shēn |
| Five | Wù chén | Twenty | Guǐ yǒu | Thirty Five | Wù chén | Fifty | Guǐ yǒu |
| Six | Jǐ sì | Twenty One | Jiǎ zǐ | Thirty Six | Jǐ sì | Fifty One | Jiǎ zǐ |
| Seven | Gēng wǔ | Twenty Two | Yǐ chǒu | Thirty Seven | Gēng wǔ | Fifty Two | Yǐ chǒu |
| Eight | Xīn wèi | Twenty Three | Bǐng yín | Thirty Eight | Xīn wèi | Fifty Three | Bǐng yín |
| Nine | Rén shēn | Twenty Four | Dīng mǎo | Thirty Nine | Rén shēn | Fifty Four | Dīng mǎo |
| Ten | Guǐ yǒu | Twenty Five | Wù chén | Forty | Guǐ yǒu | Fifty Five | Wù chén |
| Eleven | Jiǎ zǐ | Twenty Six | Jǐ sì | Forty One | Jiǎ zǐ | Fifty Six | Jǐ sì |
| Twelve | Yǐ chǒu | Twenty Seven | Gēng wǔ | Forty Two | Yǐ chǒu | Fifty Seven | Gēng wǔ |
| Thirteen | Bǐng yín | Twenty Eight | Xīn wèi | Forty Three | Bǐng yín | Fifty Eight | Xīn wèi |
| Fourteen | Dīng mǎo | Twenty Nine | Rén shēn | Forty Four | Dīng mǎo | Fifty Nine | Rén shēn |
| Fifteen | Wù chén | Thirty | Guǐ yǒu | Forty Five | Wù chén | Sixty | Guǐ yǒu |
The Origin of the Sexagenary Cycle in China
The sexageary cycle dates back to 1100 BC, when it was used as a method of recording days from the ancient written records in China. Most oracle bone inscriptions found in China today include a date under the format given by the sexagenary cycle. The use of this cycle was mostly used during the Zhou dynasty and it also served as the main documentary method for dates throughout the Han Dynasty period. In addition to that, the dates present in the Spring and Autumn Annals (the period between 722 BC and 481 BC) combines regnal months and years to record dates. Using it to record years, however, is a slightly recent activity. However, the count of years has remained uninterrupted ever since its inception. Its use has become widespread and is seen in countries such as Japan and Korea, among other countries. According to historical records, there is a Korean and Japanese tradition that involves the celebration of the sixtieth birthday in line with the sexagenary cycle.
Sexagenary Cycle Calculator
The Chinese Bazi calculator is often based on the seagenary cycle as mentioned above. The calculator is comprised of four key components related to time, which are the hour, day, month and year. These four components are often referred to as the four pillars of time and they play a critical role in determining a person’s future within the 60-year cycle. The calculation process makes it easier for one to understand themselves better, understand their career path in order to make it more meaningful and even social relationships around them, to identify the functional ones and those which are not.
Ideally, each pillar out of the four has a Heavenly Stem and an Earthly Branch. The calculator/counting system combines the solar calendar, which includes the 24 solar terms and the sexagenary cycle. Despite its ancient roots, it remains the time-keeping system that is entirely unique to China and East Asia.
Conclusion
While this traditional method of numbering days, months and years doesn’t have a significant role in China’s current calendar or in modern Chinese time-keeping, it is still valued in China. It is often encountered when discussing the Korean Imjin War, the Chinese Xinhai Revolution, the Vietnamese Tet Mau Than, and the Japanese Boshin War. Additionally, it plays a critical role in fortune telling and Chinese atrology as well.
