Lecture Notes: Sexagenary Cycle and Lunar Calendar

Introduction

• Focus on the sexagenary cycle and the lunar calendar.
• Until the 20th century, Japan (and China) used different calendrical systems than Europe and the Americas.
• Two main differences:
  1. Method of tracking years (sexagenary cycle).
  2. Method for dividing up the year (lunar calendar).

Sexagenary Cycle

• Ancient time-tracking system used in China, Japan, and Korea.
• Based on cycles of 60, created by combining 10 Heavenly Stems and 12 Earthly Branches.
• Heavenly Stems: Correspond to the five elements (wood, fire, earth, metal, water), each with older and younger brother.
• Earthly Branches: Correspond to the 12 animals of the Chinese zodiac.
• Important for historical events (e.g., auspicious first year of a cycle).
• Cycle example: Kinouene (first combination), followed by Kinoetora, Hinoi, etc.
• 60 combinations make a full cycle.

Historical Impact

• Sexagenary cycle was crucial in historical naming conventions.
• Events and periods named after the cycle year they occurred in (e.g., Boshin War, Teu Nonikai).
• Consistent across China, Japan, and Korea.

Lunar Calendar

• Japan's first calendar came from China via Korea in the 6th century.
• Lunar calendar months begin with the new moon and last about 29-30 days.
• 12 months: Generally 360 days in a lunar year, causing a drift from the solar year (365+ days).
• Intercalary Months: Added to align lunar and solar years (e.g., extra sixth month).
• Controlled by the imperial court or the shogunate in Japan's history.

Calendrical Conversion

• Conversion necessary between lunar and solar dates for historical accuracy.
• Tools like Nengo Calc assist in conversion, translating traditional dates to Western calendar dates.
• Nengo Calc offers the ability to convert dates and provides cyclical signs.
• Other resources: Tsuchihashi tables, Sino-Western calendar tables.

Practical Applications

• Historical texts often use lunar dates needing conversion for modern interpretation.
• Example: Artworks or historical events dated using cycles provide specific historical context.

Conclusion

• The sexagenary cycle and lunar calendar systems were integral to East Asian culture and history.
• Future topics: Solar calendar and the detailed measurement of time (hours and minutes).