Why Auspicious Dates for Ancestral Rites Must Avoid Clashing and Conflicting Branches

Open a Tong Shu (通书, traditional almanac) and flip to the section on ritual dates. The first thing a seasoned practitioner looks for is not the three characters "auspicious for rites" but whether the day's Earthly Branch clashes with the birth stems and branches of anyone in the household. One elder I know spent a long time crossing out dates for a seventh-day memorial rite. When the family asked why, he said: this day falls on a Chen (辰) day; the third child in the family was born in the year of the Dog — Chen and Xu (戌) are in direct opposition. Find another day. This kind of selection is widespread in folk practice. Many people ask about it; few can explain it clearly.

Clashing, Conflicting, Overcoming, and Harming Describe Four Relationships Among the Earthly Branches

Chong (冲, clashing), Xing (刑, conflicting), Ke (克, overcoming), and Hai (害, harming) are all pairwise combinations among the twelve Earthly Branches, each with its own origin.

Chong is the easiest to grasp. It refers to two Earthly Branches that sit directly opposite each other: Zi-Wu (子午), Chou-Wei (丑未), Yin-Shen (寅申), Mao-You (卯酉), Chen-Xu (辰戌), and Si-Hai (巳亥) — six pairs in all. Chong means a head-on collision, the most forceful kind of disruption. When the Tong Shu notes that "this day clashes with a certain zodiac sign," it is comparing the day's branch against a person's birth sign and marking it as unsuitable for marriage, long travel, or ancestral rites and groundbreaking — all because of that colliding energy.

Xing is more subtle than Chong. The traditional framework identifies San Xing (三刑, three-way conflicts): Yin-Si-Shen (寅巳申), Chou-Xu-Wei (丑戌未), and Zi-Mao (子卯), plus the four self-conflicting branches Chen, Wu, You, and Hai (辰午酉亥). In actual usage, Xing is often treated as more taboo than Chong, because it governs hidden change — trouble does not announce itself with a loud crack but lingers and entangles after the fact. Practitioners arranging funeral rites will generally steer around a day that falls into a San Xing pattern.

Hai (害) covers the six harming pairs: Zi-Wei (子未), Chou-Wu (丑午), Yin-Si (寅巳), Mao-Chen (卯辰), Shen-Hai (申亥), and You-Xu (酉戌). Hai is associated with hidden erosion and the opening of rifts, and folk tradition links it to petty people, quarrels, and illness. Ke (克, overcoming) is used more broadly and generally refers to Five Elements (Wu Xing) conquest — for example, the Five Elements (Wu Xing) of the day's納音 (nayin, branch-stem tone) overcoming the nayin of the deceased's birth year, or the day overcoming the presiding sacrificer's natal Five Elements (Wu Xing).

These four relationships carry different weight. My personal ranking: Chong most needs to be avoided, Xing is next, Hai after that, and Ke depends on where it falls — whether it strikes the deceased or the living, the handling differs entirely.

Why Ancestral Rites Are Especially Sensitive to These Relationships

Some find it puzzling: avoiding clashes for a wedding is understandable, but an ancestral rite is just offering incense, burning paper, and bowing — why does that need a carefully chosen date?

The answer lies in the nature of the rite itself. Traditional practice classifies ancestral rites as a Yin event (阴事), separate from Yang events (阳事) like weddings, business openings, and house moves. Yin events call for stillness and composure — for not disturbing, not agitating. Chong is about movement, rupture, and dispersal, which is exactly contrary to the settled quality a rite requires. So the same date-selection framework is used differently for Yang and Yin events: for Yang, one seeks flow and advancement; for Yin, one seeks non-disturbance.

There is also a layer that is about the living. Funerary and memorial occasions draw the family together at a moment of heightened emotion, with elders and children all present. When the date is chosen carefully, the whole family feels settled. The date-selection ritual, beyond any numerological logic, serves to put minds at ease and lend solemnity to the occasion. That value need not be dismissed, nor does it need to be elevated into a claim about spirits making their presence felt.

How to Check in Practice

The materials needed are minimal: a Tong Shu and the birth stems and branches of the relevant family members.

Step one: check the relationship between the date and the deceased. Traditional practice forbids the day's Earthly Branch from clashing with the deceased's birth-year Earthly Branch, and also flags the day's nayin Five Elements (Wu Xing) overcoming the deceased's nayin. This rule is firm for memorial rites, seventh-day rites, burials, and coffin relocations.

Step two: check the relationship between the date and the presiding sacrificer. The birth-year Earthly Branch of whoever is leading the household should not be clashed by the day's branch either. When several children are jointly presiding, check against those who will actually be present — not every relative in the extended family. Checking everyone is likely to leave no usable day at all. The relevant question is "who is presiding and who is there," not a sweep of the entire clan.

Step three: check the monthly ruling branch (月令). Traditional date selection recognizes "Yue Po" (月破, month-break days): a day whose branch clashes with the month's governing branch — for example, a Shen (申) day in the first lunar month (Yin 寅 month). Yue Po days are generally marked in the Tong Shu as unsuitable for major events, ancestral rites included.

There is also a finer layer of analysis using Shen Sha (神煞, spirit killers and gods), the Twenty-Eight Lunar Mansions, and the Jian Chu Shi Er Zhi (建除十二值, twelve-value day cycle). Within Jian Chu, the days labeled Po (破), Wei (危), and Bi (闭) are commonly avoided for funerary rites; among the Lunar Mansions, Jiao (角), Dou (斗), Kui (奎), Jing (井), and others carry auspicious or inauspicious notes depending on the Tong Shu consulted. Different editions of the almanac do not always agree on the same day, and that is normal — there is no need to debate which book is right.

Where I Hold Reservations

One popular approach applies a blanket zodiac block: if someone in the household was born in the year of the Rabbit, no Mao (卯) days are allowed. This already goes beyond the logic of Chong. The traditional application of Chong compares the date against the presiding sacrificer and the deceased, not every person in the house by birth sign. Extending the rule to a household-wide ban inflates the restriction, leaves almost no usable days, and in practice pushes people toward picking a date carelessly — which defeats the entire purpose of date selection.

I also take a cautious view of claims that a clashing or conflicting day will inevitably bring harm. Date selection is a habit of prudence around "avoiding the unfavorable," not an ironclad chain of cause and effect. No one can verify a claim that a specific day with Chong will certainly invite disaster. My approach when helping someone select a date: avoid when you can; do not panic when you cannot. Getting the rite done properly is what matters.

Unavoidable situations are common. If an elder passes on an inconvenient day and local custom calls for burial within three days, the selection window is narrow. Qing Ming (清明, Tomb-Sweeping Festival) falls at a fixed point in the calendar every year. In cases like these, the folk solution has traditionally been to look within the day: select an auspicious hour (吉时, ji shi) inside an otherwise difficult day, or hold the main ceremony during the morning when yang energy is rising. This is the old adaptive approach, not a forced workaround.

Another easy mistake: fixating on the date while ignoring the actual situation. If a child in the family has a fever, pressing on with a ceremony timed to the minute according to auspicious hours is getting things backward. Date selection serves the event; the people come first, the date second.

Applying This to Your Own Family

For ordinary memorial rites and tomb visits, the calculation does not need to be elaborate. Know the deceased's birth year; check whether the day's Earthly Branch clashes with it. That one step covers the essentials. For those who find even that cumbersome, look in the Tong Shu for days marked "auspicious for rites," avoid Yue Po days and days that clash with the deceased's branch, and that is enough for everyday purposes.

For a major burial or coffin relocation, it is worth consulting a local practitioner who knows the tradition. Regional customs vary considerably — the rules observed in the north and south of China for the same type of rite can differ by several items — and following the local practice tends to cause fewer complications than relying solely on a book.