Chapter 54 Section 4 Observation Records

There are many books on astronomy, calendar, astrology, etc. in the past dynasties, but the calendar and observation data compiled by the official observatory are basically preserved in the official twenty-five histories. In the "Historical Records", an independent space was specially set up to record the content of the calendar, which is called "almanac".From "Han Shu" to "Song History", during this period, except for "Xin Tang Shu", the contents of rhythm and calendar were all combined into one volume, so it was called "Lv Li Zhi".After the Liao Dynasty, the content of the calendar became independent again.

The Dayan calendar contained in "New Tang Book·Li Zhi" divides the content of the calendar into seven parts, namely, the technique of stepping up the breath, the technique of fading, the technique of stepping up the sun (chan tangling), the technique of stepping away from the moon, and the technique of stepping the sundial. Omission, rendezvous and five-star steps. "When the day travels, the moon travels, and when the moon travels, it departs" ("New Tang Book·Li Zhi"). The sun and the moon refer to the movement of the sun and the moon.The official history of later generations follows the writing structure of Dayan Calendar.

Regarding astronomy and astrology, the official history also has a separate volume to show its importance.This part is called "Tianguanshu" in "Historical Records", "Tianxiangzhi" in "Weishu", "Sitiankao" in "New History of the Five Dynasties", and "Tianwenzhi" in the rest of the official history . In "Historical Records·Tianguan Shu", it first introduces the names and positions of the star officials in the five palaces, then describes the phenomenon of the conjunction of the planets and accounts for their good and bad luck, then divides the fields and divination of strange astronomical phenomena, and finally describes in detail the history of astronomy. The basic structure of "Historical Records·Tianguan Shu" was used until the Ming and Qing Dynasties.