The Heavenly Plate

According to the Complete Record of Filial Piety in Upholding Principles and Harmonizing Geomancy from the Confucian School: From the third quarter after Zheng of Hai to the second quarter after Ch'u of Zi belongs to the Ren hour; from the third quarter after Ch'u of Zi to the second quarter after Zheng is truly the Zi hour; From the third quarter after Zheng of Zi to the second quarter after Ch'u of Chou belongs to the Gui hour; from the third quarter after Ch'u of Chou to the second quarter after Zheng is truly the Chou hour; From the third quarter after Zheng of Chou to the second quarter after Ch'u of Yin belongs to the Gen hour; from the third quarter after Ch'u of Yin to the second quarter after Zheng is truly the Yin hour; From the third quarter after Zheng of Yin to the second quarter after Ch'u of Mao belongs to the Jia hour; from the third quarter after Ch'u of Mao to the second quarter after Zheng is truly the Mao hour; From the third quarter after Zheng of Mao to the second quarter after Ch'u of Chen belongs to the Yi hour; from the third quarter after Ch'u of Chen to the second quarter after Zheng is truly the Chen hour; From the third quarter after Zheng of Chen to the second quarter after Ch'u of Si belongs to the Xun hour; from the third quarter after Ch'u of Si to the second quarter after Zheng is truly the Si hour; From the third quarter after Zheng of Si to the second quarter after Ch'u of Wu belongs to the Bing hour; from the third quarter after Ch'u of Wu to the second quarter after Zheng is truly the Wu hour; From the third quarter after Zheng of Wu to the second quarter after Ch'u of Wei belongs to the Ding hour; from the third quarter after Ch'u of Wei to the second quarter after Zheng is truly the Wei hour; From the third quarter after Zheng of Wei to the second quarter after Ch'u of Shen belongs to the Kun hour; from the third quarter after Ch'u of Shen to the second quarter after Zheng is truly the Shen hour; From the third quarter after Zheng of Shen to the second quarter after Ch'u of You belongs to the Geng hour; from the third quarter after Ch'u of You to the second quarter after Zheng is truly the You hour; From the third quarter after Zheng of You to the second quarter after Ch'u of Xu belongs to the Xin hour; from the third quarter after Ch'u of Xu to the second quarter after Zheng is truly the Xu hour; From the third quarter after Zheng of Xu to the second quarter after Ch'u of Hai belongs to the Qian hour; from the third quarter after Ch'u of Hai to the second quarter after Zheng is truly the Hai hour. Only from the third quarter after Ch'u of Zi to the second quarter after Zheng is truly the Zi hour. Taking one day as 100 quarters, the third quarter after Ch'u of Zi equals 10+60+60+60=190 minutes. Further, since the center of Zi is taken at 0 degrees, the Zi hour therefore begins at 3.9 degrees of the celestial circuit, not at 0 degrees on the heavenly plate. Why is this? Because the precession of the equinoxes shifts over the ages, and thus this figure arises. Checking against the Datong Calendar of 1368 does not match; the actual computation yields 3.9 degrees. If calculated with true solar terms, this number was established around 1473. Applied today, it would be more than 13 degrees.