Shen Sha in Date Selection (擇日神煞詳解)
Shen Sha (神煞) — literally 'Spirits and Killings' — are celestial and calendrical markers that indicate auspicious or inauspicious influences on a given day. In Chinese date selection (擇日), Shen Sha act as a powerful overlay that can upgrade or downgrade the quality of a date regardless of other factors. Understanding the major Shen Sha is essential for any serious practitioner.
Year-Level Shen Sha
歲破 (Sui Po — Year Breaker)
The Year Breaker occurs when the day's Earthly Branch directly clashes with the year's Earthly Branch. For example, in a Horse (午) year, any Rat (子) day is a Year Breaker. This is one of the most severe date-selection taboos — activities conducted on a Year Breaker day are believed to invite major setbacks. The Tong Shu universally marks these days as unsuitable for important activities.
Calculation: Day Branch = Clash of Year Branch. Clash pairs: 子↔午, 丑↔未, 寅↔申, 卯↔酉, 辰↔戌, 巳↔亥.
歲三煞 (Sui San Sha — Year Three Killings)
The Three Killings are a set of three inauspicious directions that rotate annually based on the year's Earthly Branch frame. When a day's Branch falls within the Three Killings frame for the year, activities in those directions are contraindicated.
Calculation: The four frames are: Water frame (申子辰 year → 巳午未 = South), Wood frame (亥卯未 year → 申酉戌 = West), Metal frame (巳酉丑 year → 寅卯辰 = East), Fire frame (寅午戌 year → 亥子丑 = North).
Month-Level Shen Sha
月破 (Yue Po — Month Breaker)
Similar to the Year Breaker but based on the month's Earthly Branch. Less severe than Sui Po but still a significant negative marker. Month Breaker days should be avoided for important activities.
Calculation: Day Branch = Clash of Month Branch.
月三煞 (Yue San Sha — Month Three Killings)
The monthly version of Three Killings, calculated using the month branch instead of the year branch. Uses the same four-frame system as the annual version.
Day-Level Auspicious Shen Sha
天德 (Tian De — Heaven's Virtue)
A powerful auspicious star that appears based on the relationship between the month branch and the day stem. Heaven's Virtue days are considered excellent for important activities, especially those requiring official approval, legal proceedings, or establishing new enterprises.
Significance: Can neutralize minor inauspicious influences. One of the 'Four Great Auspicious Stars (四大吉星)' in date selection.
月德 (Yue De — Month's Virtue)
Another of the Four Great Auspicious Stars, calculated from the month branch. Month's Virtue days are beneficial for construction, moving, and business activities.
天赦 (Tian She — Heaven's Pardon)
One of the rarest and most auspicious Shen Sha, occurring only a few times per year. Heaven's Pardon days are considered universally auspicious — they can neutralize most negative influences and are especially suitable for legal matters, corrections, and new beginnings.
Calculation: Spring (寅卯月) → 戊寅日; Summer (巳午月) → 甲午日; Autumn (申酉月) → 戊申日; Winter (亥子月) → 甲子日.
Special Avoidance Days
四離日 (Si Li — Four Separation Days)
The day before each of the four seasonal markers (Spring Equinox, Summer Solstice, Autumn Equinox, Winter Solstice). These are transitional days when the seasonal energy is shifting — not suitable for initiating new activities.
四絕日 (Si Jue — Four Extinction Days)
The day before each of the four seasonal beginnings (Li Chun, Li Xia, Li Qiu, Li Dong). The old season's energy has exhausted itself — a period of energetic vacuum unsuitable for important activities.
受死日 (Shou Si Ri — Death-Receiving Day)
A cyclical pattern where specific day branches in specific months are marked as extremely inauspicious. These days carry the strongest avoidance recommendation in the classical almanac.
楊公忌日 (Yang Gong Ji Ri — Yang Gong Taboo Days)
Thirteen specific days per year attributed to the legendary Feng Shui master Yang Yun Song (楊筠松). These days begin on the 13th of the 1st lunar month and follow a specific pattern through the year. Activities conducted on these days are believed to invite misfortune.
Interaction Rules
Shen Sha do not operate in isolation. Key interaction principles:
- A single auspicious Shen Sha (Tian De, Yue De, Tian She) can neutralize 1–2 minor inauspicious markers.
- Year Breaker (歲破) and Three Killings (三煞) cannot be neutralized and override all other positive indicators.
- Multiple auspicious Shen Sha on the same day create a compounding positive effect.
- Shen Sha should be evaluated after the Day Officer (建除) and before Dong Gong grading for the most accurate composite assessment.