闰月
御定星历考原 · section 11 · 李光地 等 奉敕撰 · 390 characters
Original text
左传曰先王之正时也履端于始举正于中归余于终履端于始序则不愆举正于中人则不惑归余于终事则不悖蔡氏书传曰岁有十二月月有三十日三百六十者一岁之常数也故日与天会而多五日九百四十分日之二百三十五为气盈月与日会而少五日九百四十分日之五百九十二为朔虚合气盈朔虚而闰生焉故一岁闰率则十日九百四十分日之八百二十七三岁一闰则三十二日九百四十分日之六百单一五岁再闰则五十四日九百四十分日之三百七十五十有九岁七闰则气朔分齐是为一章也汉志曰至朔同日谓之章同在日首谓之蔀蔀终六旬谓之纪岁朔又复谓之元是故日以实之月以闰之时以分之岁以周之章以明之蔀以部之纪以记之元以原之元法四千五百六十纪法千五百二十蔀法七十六章法十九故十九年为一章四章为一蔀二十蔀为一纪三纪为一元汲冢周书曰中气以着时应闰无中气斗柄指两辰之间故闰前之月中气在晦闰后之月中气在朔当闰之月节居月中以前作前月用事以后作后月用事所以定四时成岁者不越乎此矣
This site's reading
The reading for this section has not been written yet; the original text above is complete.
The text is reproduced from the named edition without alteration. The reading is this site's own; commentators differ. Where the book judges 格局 or 用神 it is stating doctrine, not a conclusion about the reader's own chart.
Witness: https://zh.wikisource.org/wiki/%E5%BE%A1%E5%AE%9A%E6%98%9F%E5%8E%AF%E8%80%83%E5%8E%9F%20(%E5%9B%9B%E5%BA%AB%E5%85%A8%E6%9B%B8%E6%9C%AC) · wikisource/御定星厯考原_四庫全書本_卷1.txt · sha 09abc9924892d4dd
Read this against your own chart
Cast your own four pillars first, then come back to the text.