Every day in a Chinese almanac (Huangli / Tong Shu) carries a single character from this list: Establish (建), Remove (除), Full (满), Balance (平), Settle (定), Hold (执), Break (破), Peril (危), Success (成), Gather (收), Open (开), Close (闭). Together they are the Jian Chu system, the Twelve Day Officers. This guide explains where they come from, the exact counting rule, the "repeat day", and how to read them in the almanac.
Origins
The system is old. Day-books (Rishu) excavated from Qin and Han tombs already arrange days by Jian Chu, and the Huainanzi ("Treatise on the Patterns of Heaven") gives the sequence "Yin is Establish, Mao is Remove, Chen is Full, Si is Balance…". In the Yin (first) month, a Yin day is Establish, a Mao day Remove, and so on. Later almanacs, including the Qing imperial compendium Xieji Bianfang Shu, kept it as a basic layer of date selection. It is still printed in almanacs today.
The counting rule
One rule does all the work: within each month, the day whose earthly branch matches the month's branch is "Establish"; the following days run Remove, Full, Balance, Settle, Hold, Break, Peril, Success, Gather, Open, Close, then repeat every twelve days.
Two terms matter:
- Month branch (月建) — month 1 is Yin, month 2 Mao, month 3 Chen … month 11 Zi, month 12 Chou.
- Solar-term months — the "month" here is not the lunar month that starts on the new moon. It is the solar-term month, which begins at a jie term: Start of Spring begins the Yin month, Awakening of Insects the Mao month, Clear and Bright the Chen month, then Start of Summer, Grain in Ear, Minor Heat, Start of Autumn, White Dew, Cold Dew, Start of Winter, Major Snow and Minor Cold.
Example: after Cold Dew comes the Xu month. The first Xu day is Establish, the next (Hai) day is Remove, the Zi day is Full, the Chou day Balance, and so on.
Why one officer repeats
If the officers simply follow the day branch, why do two consecutive days sometimes share one? On the day a jie term begins, the month branch moves forward by one and so does the day branch, so the gap between them, and therefore the officer, stays the same. Each of the twelve jie terms produces one repeat, so roughly twelve per year.
Checked with the calendar library MoZhu's almanac uses (lunar-javascript 1.7.7, noon of each day, field getZhiXing()):
| Date | Solar term | Month branch | Day stem-branch | Officer |
|---|---|---|---|---|
| 2026-10-07 | — | You | Jia-Yin | Hold |
| 2026-10-08 | Cold Dew | Xu | Yi-Mao | Hold |
| 2026-10-09 | — | Xu | Bing-Chen | Break |
On Cold Dew the month branch changes from You to Xu, so Hold repeats before the count moves on to Break. Start of Spring 2027 works the same way: 3 February (month Chou, day Chou) is Establish, and 4 February, Start of Spring (month Yin, day Yin), is Establish again. Across all of 2027 the month branch changes 12 times, and every time the officer repeats.
Reading it in the almanac
Take an ordinary day: 17 October 2026, a Jia-Zi day in the Xu month after Cold Dew. Counting from the Xu day (Establish), Hai is Remove and Zi is Full, so it is a Full day. Its Suitable list includes proposals, betrothal, visiting relatives, tailoring and placing a bed. Its Avoid list includes opening a business, moving in, travel and weddings. Several public almanacs also record it as a Full day.
Three things to keep in mind:
- It is a category. Each character carries a plain meaning: Remove suggests clearing out, Success completion, Open beginning, Close storing away. Almanacs pair activities with them.
- It does not set the Suitable / Avoid lists alone. Modern almanacs combine the officer, the day's stem-branch, the month and various named stars in their tables. The same Full officer can carry different lists in different months.
- It is separate from yellow / black path days. Those come from twelve day deities (Azure Dragon, Bright Hall and so on) that rotate on their own. Folk verses link the two systems, but sources disagree.
Summary
The rule is simple: the day matching the month branch is Establish, count the twelve officers in order, and repeat one whenever a jie term begins. With that, the single character on each almanac page makes sense. It is a long-lived part of the traditional calendar, best read as cultural knowledge.
This article is for cultural reference only and is not advice for any decision.