What is the Sexagenary Cycle?
The Sexagenary Cycle (Liushijiazi 六十甲子) consists of 60 combinations formed by pairing 10 Heavenly Stems with 12 Earthly Branches. It begins with 'Jia-Zi (甲子)' and cycles through to 'Gui-Hai (癸亥)'.
These 60 stem-branch combinations are used to mark years, months, days, and hours. After 60 years, the same combination returns, which is called 'Huanjia (還甲)' or completion of one cycle.
Why 60 Combinations?
The least common multiple of 10 (Stems) and 12 (Branches) is 60. Since Stems and Branches only combine Yang with Yang and Yin with Yin, this creates exactly 60 combinations (10 × 12 ÷ 2 = 60).
Complete Sexagenary Cycle Table
| No. | Stem-Branch | No. | Stem-Branch | No. | Stem-Branch |
|---|---|---|---|---|---|
| 1 | 甲子 Jia-Zi | 21 | 甲申 Jia-Shen | 41 | 甲辰 Jia-Chen |
| 2 | 乙丑 Yi-Chou | 22 | 乙酉 Yi-You | 42 | 乙巳 Yi-Si |
| 3 | 丙寅 Bing-Yin | 23 | 丙戌 Bing-Xu | 43 | 丙午 Bing-Wu |
| 4 | 丁卯 Ding-Mao | 24 | 丁亥 Ding-Hai | 44 | 丁未 Ding-Wei |
| 5 | 戊辰 Wu-Chen | 25 | 戊子 Wu-Zi | 45 | 戊申 Wu-Shen |
| 6 | 己巳 Ji-Si | 26 | 己丑 Ji-Chou | 46 | 己酉 Ji-You |
| 7 | 庚午 Geng-Wu | 27 | 庚寅 Geng-Yin | 47 | 庚戌 Geng-Xu |
| 8 | 辛未 Xin-Wei | 28 | 辛卯 Xin-Mao | 48 | 辛亥 Xin-Hai |
| 9 | 壬申 Ren-Shen | 29 | 壬辰 Ren-Chen | 49 | 壬子 Ren-Zi |
| 10 | 癸酉 Gui-You | 30 | 癸巳 Gui-Si | 50 | 癸丑 Gui-Chou |
| 11 | 甲戌 Jia-Xu | 31 | 甲午 Jia-Wu | 51 | 甲寅 Jia-Yin |
| 12 | 乙亥 Yi-Hai | 32 | 乙未 Yi-Wei | 52 | 乙卯 Yi-Mao |
| ... | ... | ... | ... | ... | ... |
| 60 | 癸亥 Gui-Hai | → Cycles back to Jia-Zi | |||
Day Pillar and Personality
The stem-branch combination of your birth day is called the Day Pillar (Rizhu 日柱). The Day Pillar represents your core personality, and each of the 60 pillars has unique characteristics.
Characteristics of Representative Day Pillars
Huanjia (還甲) - Completion of the Cycle
After 60 years, the same stem-branch combination as your birth year returns. This is called Huanjia (還甲) or Huijia (回甲). In the past, when life expectancy was shorter, reaching Huanjia was a great celebration.
The Meaning of Huanjia
Huanjia signifies completing one full cycle of life. From the perspective of beginning a new 60-year cycle, life after Huanjia is also called 'the second life'.
Applications of the Sexagenary Cycle
- Year Pillar: Birth year (used with zodiac animal)
- Month Pillar: Birth month (based on solar terms)
- Day Pillar: Birth day (core personality)
- Hour Pillar: Birth hour (2-hour intervals)
- Major Luck: Flow of fortune in 10-year periods
- Annual Luck: Fortune for each year