Chinese calendar

2637 BCE

Chinese calendar

The book of science

Tom Sharp

Huangdi astronomy Chinese calendar

Chinese calendar

Lord Huangdi, the Yellow Emperor, decreed in 2637 BCE a lunisolar calendar governing months, holidays, and auspicious dates. Each day begins at midnight. Each month begins on the day of the dark moon. Each year begins with the month between winter solstice and spring equinox. A leap month is inserted whenever a year has 13 new moons. Each year is divided into 24 solar terms. Each solar term is divided into three groups of days called pentads. Most years have 12 months; leap years have 13. Most years have between 353 and 355 days; leap years have between 383 and 385.

Celestial stems and terrestrial branches

The years have sixty names using ten celestial stems (having no translations in English) and twelve terrestrial branches (having names of beasts) so that every sixty-year cycle starts with jia-zi and ends with gui-hai and contains six years of the rat six of the ox six of the tiger six of the hare six of the dragon six of the snake six of the horse six of the sheep six of the monkey six of the rooster six of the dog and six of the pig.

1. jia-zi (rat) 2. yi-chou (ox) 3. bing-yin (tiger) 4. ding-mao (hare) 5. wu-chen (dragon)
6. ji-si (snake) 7. geng-wu (horse) 8. xin-wei (sheep) 9. ren-shen (monkey) 10. gui-you (rooster)
11. jia-1u (dog) 12. yi-hai (pig) 13. bing-zi (rat) 14. ding-chou (ox) 15. wu-yin (tiger)
16. ji-mao (hare) 17. geng-chen (dragon) 18. xin-si (snake) 19. ren-wu (horse) 20. gui-wei (sheep)
21. jia-shen (monkey) 22. yi-you (rooster) 23. bing-1u (dog) 24. ding-hai (pig) 25. wu-zi (rat)
26. ji-chou (ox) 27. geng-yin (tiger) 28. xin-mao (hare) 29. ren-chen (dragon) 30. gui-si (snake)
31. jia-wu (horse) 32. yi-wei (sheep) 33. bing-shen (monkey) 34. ding-you (rooster) 35. wu-1u (dog)
36. ji-hai (pig) 37. geng-zi (rat) 38. xin-chou (ox) 39. ren-yin (tiger) 40. gui-mao (hare)
41. jia-chen (dragon) 42. yi-si (snake) 43. bing-wu (horse) 44. ding-wei (sheep) 45. wu-shen (monkey)
46. ji-you (rooster) 47. geng-1u (dog) 48. xin-hai (pig) 49. ren-zi (rat) 50. gui-chou (ox)
51. jia-yin (tiger) 52. yi-mao (hare) 53. bing-chen (dragon) 54. ding-si (snake) 55. wu-wu (horse)
56. ji-wei (sheep) 57. geng-shen (monkey) 58. xin-you (rooster) 59. ren-1u (dog) 60. gui-hai (pig)

God, myth, man

If Huangdi were a god, then his holidays and auspicious days would be ordained, sacred, and blessed. If Huangdi were a myth, then what is this living pattern of days that we attribute to him? If Huangdi were a metaphor, then his calendar would show how things could be both rational and aligned with the universe. If Huangdi were a man, why should we not say a god could be anything he likes? Why couldn’t a god play the part of an emperor and take credit for another’s work?

The year 2018 is 4716 according to the Chinese calendar, although the calendar started in 2637 BCE. Originally, counting started over for each new emperor, but before the 1911 revolution Sun Yat-sen established this count assuming that the first year of the Yellow Emperor was in 2698 BCE.

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