How the Chinese Almanac (Tong Shu) Works, Page by Page
The Tong Shu has marked lucky and unlucky days for a thousand years. Here is how a single page is built, layer by layer, from stems and branches to lucky hours.
Around Lunar New Year, the same thin red booklet shows up on street corners and grocery store counters across the Chinese-speaking world. It costs almost nothing. It is printed on paper that smudges. Its pages are packed with columns of tiny characters, and most readers under forty walk right past it.
That booklet is the Tong Shu. Households have bought one every year for centuries, not to read cover to cover but to answer a single question before anything that matters. Is this a good day, or not?
Plenty of guides explain how to use the answers. This one opens the book instead. Behind that dense page of characters sit several separate calendar systems stacked on top of one another, and some of them are older than the printing press that carries them.
The book and its names
The full name is 通書 (Tong Shu), roughly “the book that covers everything.” In Cantonese-speaking regions it turned into 通勝 (Tong Sheng). That change was not poetic. 書 (shū, book) sounds like 輸 (shū, to lose), and shopkeepers did not want a losing book on the counter. Swapping in 勝 (shèng, to win) settled the matter. Both names point to the same object.
The other common label is 黃曆 (Huang Li), the yellow calendar. The color goes back to imperial times, when the court issued the official calendar each year on yellow paper. Handing out a calendar was an act of political authority. Whoever controls the calendar controls the festival days, the planting seasons, and the tax deadlines. For long stretches of history, printing your own was a punishable offense.
Mass printing broke that grip. By the Ming and Qing dynasties, commercial almanacs were everywhere, and the modern version is their direct descendant. The core content barely changed, and neither did the layout.
Three calendars on one page
An almanac page reads like a single system. It is really three, layered.
The first is the lunar month. Months begin at the new moon and run 29 or 30 days. Twelve of them add up to about 354 days, which drifts against the seasons by roughly eleven days a year. Left alone, the New Year festival would wander from winter into summer and back.
The second is the sun. The 24 solar terms (二十四節氣) mark fifteen-degree steps along the sun’s path, so they track the seasons rather than the moon. Their job is to keep the lunar calendar honest.
The two are reconciled by the leap month. Every two or three years, a thirteenth month is inserted. The rule is precise: any lunar month that contains no major solar term becomes the leap month. Nineteen years carry seven leap months in total, which is why Lunar New Year lands somewhere between late January and late February, never fixed.
The third system is the one that does most of the work. The ten Heavenly Stems and twelve Earthly Branches (天干地支) pair up into sixty combinations, and the cycle runs without a break, one step per day, for over two thousand years. Every date on the page carries one of those sixty labels, and nearly every rating below it is derived from that label.
What is printed on a single page
Flip to any day and the same lines appear in the same order. Once you can name them, the page stops looking like a wall of text.
| Line on the page | What it means |
|---|---|
| Gregorian date | The Western date, printed alongside everything else |
| Lunar date | Which lunar month and day the date falls on |
| Day pillar (干支) | The day’s stem and branch, plus its zodiac animal |
| 建除 Twelve Officers | One of twelve daily positions, each suited to different activity |
| 黃道 / 黑道 | One of twelve spirits, six auspicious and six not |
| 二十八宿 | One of the 28 lunar mansions, on a 28-day rotation |
| 沖煞 | The zodiac sign the day clashes with, plus a direction to avoid |
| 胎神 | Where the fetal spirit is said to sit that day |
| 宜 / 忌 | The list of suitable and unsuitable activities |
| 吉時 | The favorable two-hour segments inside the day |
| 彭祖百忌 | Two taboos tied to the day’s stem and branch |
The first four lines set the day’s overall character. The next two, the clash and the fetal spirit, are warnings. The last three tell you what to actually do with the day once you have read it.
The Twelve Officers
The Twelve Officers (建除十二神) give the day its headline rating. Each day carries one of twelve positions, and the cycle advances one step per day without ever resetting. Establishment suits beginnings. Success and Open suit launches and completions. Destroy and Danger are the two everyone steers around.
The full cycle and how it maps to real events is worth its own read. The auspicious date selection guide walks through all twelve positions and what each one favors.
Yellow Path and Black Path
Sitting next to the Officers is a second, independent rating. Twelve spirits alternate between the Yellow Path (黃道) and the Black Path (黑道), six of each. A day whose spirit falls on the Yellow Path is what people mean by a genuinely lucky day. When the Officer cycle and the spirit cycle agree, the rating is strong in either direction.
Two overlapping ratings instead of one is a deliberate design. A single system can be argued with. Two that must agree are harder to dismiss, which is part of why the book survived.
The 28 lunar mansions
Less familiar to Western readers, the 二十八宿 divides the sky along the sun’s path into 28 segments, each named for a constellation or a nearby star group. The day’s mansion advances one step every day on a 28-day rotation, running in parallel with the 60-day stem and branch cycle.
| Direction | Mansions |
|---|---|
| East (Azure Dragon) | 角 亢 氐 房 心 尾 箕 |
| North (Black Tortoise) | 斗 牛 女 虛 危 室 壁 |
| West (White Tiger) | 奎 婁 胃 昴 畢 觜 參 |
| South (Vermilion Bird) | 井 鬼 柳 星 張 翼 軫 |
Each mansion carries a fixed reputation, some favorable and some not, and the almanac prints the day’s mansion near the top. Most people never learn the names. The information is there as a third filter for anyone comparing several candidate dates and looking for a tiebreaker.
The clash line, and why it is personal
Every other rating on the page applies to everyone equally. The clash line does not. Each day carries an Earthly Branch, each branch belongs to a zodiac animal, and if that animal sits directly opposite your birth year’s animal, the day is considered poor for you no matter how good the rest of the page looks.
A Rat avoids Horse days. A Dragon avoids Dog days. It is a strict rule, and it is the one check that turns an otherwise excellent date into a bad one for a specific person.
The same line usually carries a direction as well, the 煞 (shà). Each branch points to one of the compass directions, and the traditional advice is to keep digging, renovation, and ground-breaking away from it that day. Modern readers treat it as a mild caution rather than a hard rule.
The fetal spirit and the old taboos
Two of the strangest lines on a page are also among the oldest.
The 胎神 (Tāi Shén), or fetal spirit, is given a location that changes daily: a room, a piece of furniture, a corner of the house. Households with a pregnancy in them were warned not to drill, hammer, or move furniture in that spot, on the belief that disturbing the spirit endangered the child. It is folk belief more than astronomy, and it survives because pregnant families still find it a reasonable excuse to postpone a renovation.
The 彭祖百忌 (Peng Zu’s hundred taboos) are two short lines attached to the day’s stem and its branch. Each of the ten stems and twelve branches carries one taboo. On a 甲 day, for instance, the line warns against opening a granary. On a 子 day, against consulting a fortune teller. The advice is agricultural and commercial, inherited from an economy of farms and storehouses, and modern almanacs keep printing it out of habit and continuity.
Where the suitable and unsuitable lists come from
The 宜 (suitable) and 忌 (unsuitable) columns are the part everyone actually reads, and they are not generated from a single rule. They are assembled from everything above: the day’s Officer, its spirit, its mansion, its clash, its stem and branch, and a set of named star deities that each favor or forbid certain actions.
That is why the same activity can appear on one day’s 宜 list and another day’s 忌 list with no contradiction. The lists are a summary of a stack of separate judgments, and the almanac has already done the arithmetic. For a wedding, a move, or a contract signing, the final answer is simply which column the activity landed in.
The twelve hours
The last practical line is 吉時, the favorable hours. Each day divides into twelve two-hour segments, named after the Earthly Branches. 子時 runs from 11 p.m. to 1 a.m., and the sequence continues around the clock. Every segment gets its own rating, and the almanac prints the good ones.
This matters when a date cannot be moved. If the only available day is mediocre, the traditional move is to schedule the key moment, the signing or the first entry, inside one of the day’s favorable hours. It does not fix the date. It does give the event a better window than the day as a whole offers.
Reading a page in five minutes
If you want to use the book rather than study it, the sequence is short.
Check the Officer first. If it is Destroy or Danger, and your event is a beginning, stop there. Check the Yellow or Black Path next. Then scan the clash line against your own birth year. Finally, read the 宜 and 忌 columns for your specific activity, and note the favorable hours.
Four checks, in that order, will filter a page faster than reading every line on it. Most days never make it past the first two.
What the almanac is, and what it is not
The Tong Shu is not a horoscope. Nothing on the page depends on your birth chart, and no astrologer reads your fate from it. It is a scheduling system, closer in spirit to a farmer’s almanac than to a personal reading, and its oldest layers are astronomical: the moon, the sun, and a sixty-day count that has not skipped a day in recorded memory.
The ratings on top of those layers are cultural. They encode centuries of accumulated advice about timing, and they work the way most traditions work. People follow them because the discipline of choosing a date deliberately makes an event feel considered, and because a family that agrees on the method stops arguing about the day.
That is a more modest claim than fate, and it is the one the book actually supports.
Common questions
What is the difference between the Tong Shu and the lunar calendar? The lunar calendar only gives you dates. The Tong Shu adds a rating on top of each date, marking what is suitable and unsuitable, which zodiac sign it clashes with, and which hours are favorable. Every Tong Shu contains the lunar calendar, but the lunar calendar alone carries no luck ratings.
Is the Tong Shu the same as the Huang Li? Yes. Huang Li (yellow calendar) and Tong Shu (book of everything) are two names for one publication. The Cantonese variant is Tong Sheng, changed from Tong Shu because the word for book sounds like the word for losing. The content is the same under all three names.
Do I need to read Chinese to use an almanac? No. The ratings rest on a small set of rules that translate cleanly: a 60-day cycle of stems and branches, a 12-day officer cycle, a zodiac clash line, and a list of suitable and unsuitable activities. English almanacs and online tools present the same output without the characters.
Why does the almanac warn about a specific direction each day? That is the sha (煞), the direction the day’s energy is said to oppose. It comes from the day’s Earthly Branch, and each branch points to one of the compass directions. The traditional advice is to avoid digging, renovating, or breaking ground facing that direction.
Can a day be good for one person and bad for another? Yes, through the zodiac clash. The daily ratings apply to everyone, but if the day’s animal sits opposite your birth year’s animal, the date is considered poor for you regardless of everything else on the page. It is the one personal check built into the book.
Before you pick the next date that matters, run it through the checker. It reads the same layers this article describes, from the day’s Officer to its clash and its favorable hours, and returns the verdict in about two minutes. If you are planning a season ahead, the Auspicious Date Calendar maps twelve months of ratings at once and marks the days that clash with your sign. For the practical side of choosing a day rather than reading the book that describes it, the date selection guide covers weddings, openings, and moves in detail.