Day spirit
Qīng Lóng
Azure Dragon
An almanac describes traditional day-types. It cannot decide health, money, law, marriage or children. Burial, marriage and medical items on these pages are what a book states, never advice.
In the classical sources
斗始寅嵗且更始焉故寅為青龍
The Dipper starts at 寅 and the year begins again there, so 寅 is the Azure Dragon.
協紀辨方書 卷七
About this entry
星厯考原 卷五 numbers 青龍 first among twelve spirits that run through the day branches, and six of the twelve are called 黃道, the yellow path. In a 寅 or 申 month it lands on 子 days, and in the next pair of months it moves two branches along. 協紀辨方書 卷七 quotes 李鼎祚, who starts it at 子 in the first month and steps it through the six yang branches.
協紀 quotes the older 神樞經 for the claim that the six yellow-path spirits suit every sort of undertaking, with harmful forces giving way of themselves. The editors of 1741 point out that nobody explains why. Their own account places 青龍 at the 寅 branch, where the Dipper's year begins.
A second use of the color words exists: a rhyme quoted in 協紀 卷四 labels some officers black and others yellow. This site uses only the twelve-spirit meaning, so a day can be 青龍 and carry a black-labeled officer at once. 曹震圭 gave the spirit a second name, 雷公, and 邵泰衢 blames that thunder name for books that listed it as black.
Where this text comes from
The Chinese follows the Wikisource typed text of the Siku copy, under its CC BY-SA terms. Statements about the calculator describe its own rules, and modern practice is labeled as modern.
The English here is our own plain wording. Lists keep the items of the source.