Source Aslaksen 2003 Yinyang li nong li Lunisolar

Source: Aslaksen, 2003.

阴阳历 农历 Yinyang li nong li “Lunisolar cal. ” 年 Btw. Chinese New years “Agricultural cal. ” = Solar 岁 Btw. 2 winter solstices

1276 (Yuan dynasty) by Guo Shoujing Gnomon @ Gaocheng Astronomical Observatory

24 Solar Terms 节气 jiéqì

闰月 שנת עיבור , חודשי עיבור Metonic Cycle - 235 months = 19 years 6939. 6884 ~ 6939. 6018 Known in China as Zhang (章）cycle, circa 600 BC Used until 104 BC.

Month length 大月dayue: 30 d. 小月xiao yue: 29 d.

קביעת חודשי העיבור 闰月法 Leap year Yes / No: If there is a new Moon on the day after the December solstice or within about 11 days, the su`ı is a leap su`ı. If there is a new Moon on the same day as the December solstice or the first new Moon after the December solstice is more than about 12 days later, it is a normal year. If yes, which month: In a leap su`ı � , the first month that doesn’t contain a zh¯ong q`ı 中气 is the leap month.

קביעת חודשי העיבור 闰月法 Leap months can theoretically be any month. But. . Since 1645 reform, months 1 and 12 never have leap. According to Aslaksen: 2262 will have leap on 1 st month 3358 will have leap on 12 th month

清明上河图 Qingming Riverside

רפורמת 1645 Tang Ruowang (Adam Schall) Kepler's second law. . from “mean sun” (平气） to “true sun” (定气） Before: 30. 44 days btw 中气 After: 29. 44 -31. 44 d. btw 中气