Chinese Calendar Date Selection
The Chinese almanac rates every day on dozens of indicators. The calculator takes eight main rules — the Day Officer, the Yellow Path, the lunar mansion, the Year and Month Breakers, the Four Separations and Four Extinctions days, the Yang Gong dates and personal clashes — and selects days for your undertaking. For every day you can see which rules it passed and which it didn't.
Your date of birth is optional, and the time and place of birth are not needed. For a wedding, you can also enter your partner's date. All calculations run in your browser. Only what you choose to send for an AI reading goes to the server, and we cut out the date of birth: the AI learns only the birth year in the Chinese calendar and the days that clash with it.
Which Rules Apply
The calculator checks every day of the period against eight rules of the Chinese almanac. Five rules are restrictions only: a day that breaks even one of them can't make the best list. The day's path and mansion only add points, while the Day Officer can both exclude a day and give it points.
- Day Officer (建除十二神): one of the twelve “spirits” of the cycle from Establish to Close. It is determined by the day branch relative to the branch of the solar month. For each activity the officer has a verdict: “good for,” “bad for” or “not mentioned.” The sources are the Xie Ji Bian Fang Shu (协纪辨方书), a compendium of date-selection rules compiled by order of the Qianlong Emperor in 1739, and the short Tong Shu almanac lists from our calendar pages. “Bad for” excludes the day; “good for” adds 2 points.
- Day path (黄道/黑道): one of the twelve spirits from Azure Dragon to Hooked Array. Six of them make up the “Yellow Path”: such a day gets 1 point.
- Lunar mansion (二十八宿): one of twenty-eight. A mansion that is auspicious according to the traditional list gives 1 point.
- Year Breaker (岁破): the day branch clashes with the year branch, with the year counted from Lichun. The Xie Ji forbids construction, moving house, weddings and long journeys on such a day, so for these activities the day is excluded.
- Month Breaker (月破): the day branch clashes with the month branch; this is always a Destruction officer day. According to the Xie Ji, nothing on our list may be done on it except medical treatment and study.
- Four Separations and Four Extinctions (四离, 四绝): the eves of the equinoxes and solstices and the eves of the four “starts”: of spring, summer, autumn and winter. Counted in Beijing time: the day is excluded if one of these eight solar terms begins the next day.
- The thirteen Yang Gong dates (杨公忌): in each lunar month, two days earlier than in the previous one: the 13th of the first month, the 11th of the second, the 9th of the third, the 7th of the fourth, the 5th of the fifth, the 3rd of the sixth, the 1st and 29th of the seventh, the 27th of the eighth, the 25th of the ninth, the 23rd of the tenth, the 21st of the eleventh and the 19th of the twelfth. These dates aren't among the rules of the Xie Ji; they are a tradition of the popular almanacs, and we include it because many modern Tong Shu follow it. In a leap month the dates are not marked.
- Personal clash (冲): if a date of birth is entered, days whose branch is opposite the branch of the birth year or of the birth day are excluded. For a wedding, both dates are used.
We checked the Day Officer, path, mansion, clashes, Month Breaker and Yang Gong dates against the independent lunar-javascript library for every day from 2020 to 2030, and the Year Breaker and the Four Separations and Four Extinctions against the lunisolar library: they match completely.
Day Officers and Activities
This is how the two sources are combined: “+” means good for, “−” bad for, “·” not mentioned. The Xie Ji lists are supplemented with the month spirits that by construction always fall on the same day: Heavenly Doctor (天医) on Success, Blood Branch (血支) on Close, and others. If one source allows something and the other forbids it, the prohibition wins.
| Day Officer | Moving house | Wedding | Activity | Trip | Construction | Treatment | Study | Purchase |
|---|---|---|---|---|---|---|---|---|
| Establish 建 | − | − | · | + | − | − | · | · |
| Remove 除 | − | − | − | + | · | + | · | · |
| Full 满 | · | − | + | · | · | − | · | + |
| Balance 平 | − | − | − | − | −* | − | − | − |
| Stable 定 | + | + | + | − | + | − | · | + |
| Initiate 执 | − | · | − | − | + | · | · | − |
| Destruction 破 | − | − | − | − | − | + | − | − |
| Danger 危 | · | · | · | − | · | · | · | · |
| Success 成 | + | + | + | + | + | + | + | + |
| Receive 收 | − | − | − | − | − | − | · | + |
| Open 开 | + | + | + | + | + | + | + | · |
| Close 闭 | − | − | − | − | − | − | − | · |
* The Xie Ji forbids any construction on a Balance day, while the short Tong Shu list recommends it for repairs. The calculator follows the prohibition and says so in the day's breakdown.
How the Ranking Works
First, days with even one restriction are filtered out. The rest get points: 2 if the officer is directly good for the activity, 1 for the Yellow Path, 1 for an auspicious mansion. The maximum is 4 points. Up to seven days with the highest score make the best list; in a tie, earlier days come first.
The weights are simple and open. Tradition ranks the Day Officer above the path and the mansion, so it counts double. The classical texts give no other weights: masters decide differently what matters more, and we don't make that decision for them.
How to read the table
- Officer: marked “+,” “−” or “·” for the chosen activity.
- Path: ● Yellow, ○ Black.
- Mansion: “+” auspicious, “−” not.
- Restrictions: which rules the day broke. A dash means none.
- Score: from 0 to 4; days with a restriction get no score.
The best days are highlighted in gold, and days with restrictions are grayed out. Dates in 2026–2027 link to day pages with the hours, pillars and a full almanac breakdown.
An Honest Look at the Method
The rules here are calculated precisely: the solar terms from astronomical tables, the cycles and branches by the tradition. But the “good for / bad for” lists differ between almanac editions, and the full Xie Ji method takes into account dozens of day spirits — Heavenly Virtue, Monthly Virtue, Heavenly Pardon and many others — that lift or reinforce restrictions.
We compared the calculator's verdicts with the “good for / bad for” lists of the lunar-javascript library for 2020–2030. Across all eight activities combined, the library marks the days the calculator lets through as “bad for” noticeably less often than the days it filters out: 21% versus 34%. But even among the days let through, “good for” appears in only a third of cases. Two libraries that both draw on the Xie Ji, lunar-javascript and lunisolar, disagree with each other just as much: of the days the first calls good for our activities, the second forbids a third for the same activity. There is no single “correct” almanac.
What the calculator deliberately doesn't do: it doesn't promise luck, doesn't call a day “your personal lucky day,” and doesn't use spirits and stars whose rules we can't write down unambiguously and test. There's no verifiable evidence that something started on a day chosen this way goes better. This is a way to follow the tradition if it matters to you, not a forecast. The timing of medical treatment, deals and trips is decided by doctors, lawyers and common sense.
Related in This Section
Frequently asked questions
How do I choose an auspicious day by the Chinese calendar?
Choose the activity, the start of the period and its length — up to three months. The calculator will discard days with restrictions and rank the rest by score: Day Officer, Yellow Path and an auspicious mansion. Enter your date of birth, and it will exclude days that clash with your birth year and birth day.
Do I need my time of birth?
No. These rules only need the year by Lichun and the day pillar of your birth, and the date gives you both. If you were born on the day of Lichun, around February 4, the calculator checks both possible years.
Why do almanacs give different lists for the same day?
The full method of the Xie Ji Bian Fang Shu takes into account dozens of day spirits and stars, and almanac editions combine them in different ways. The calculator applies a small, open set of rules and shows each one, so you can check its answer by hand.
Is there any evidence that such a day is luckier?
No. There's no verifiable evidence that something started on an “auspicious” day goes better. The calculator follows the rules of the tradition precisely, but it doesn't predict the outcome.
For a wedding, do we need both birth dates?
It's advisable. For a wedding or engagement you can also enter your partner's date: days that clash with the birth year or birth day of either of you will be excluded.