IV. The Foundational Use of the Heavenly Stems and Earthly Branches in Judging a Shop

1. The Levels of the Ten Heavenly Stems and Twelve Earthly Branches

The Ten Heavenly Stems (tiangan) are Jia, Yi, Bing, Ding, Wu, Ji, Geng, Xin, Ren, and Gui, each carrying a yin-yang and Five Phases attribute. Jia and Yi belong to Wood; Bing and Ding to Fire; Wu and Ji to Earth; Geng and Xin to Metal; Ren and Gui to Water — the first of each pair takes yang, the second yin. The Twelve Earthly Branches (dizhi) are Zi, Chou, Yin, Mao, Chen, Si, Wu, Wei, Shen, You, Xu, and Hai, likewise divided by yin-yang and the Five Phases, and each corresponding to a month, a double-hour, and a direction.

In commercial fengshui, the stems and branches serve chiefly three purposes. First, the Twenty-Four Mountains array the eight stems, twelve branches, and four corner trigram positions together around a full circle, used to refine the sitting and facing directions. Second, date selection uses the stems and branches of the year, month, day, and hour to judge clashes, harmonies, generation, control, and the framework of auspicious and inauspicious spirits (shensha). Third, the traditional reminders concerning the annual Grand Duke (Taisui), the year-breaking direction (suipo), and the Three Killings (sansha) must be located on the branch directions. This article does not expand the stems and branches into a full system of personal fate-pillars, but treats only the parts directly relevant to the shop's space and timing.

2. Reading the Space of Branch Directions, Clashes, and Harmonies

Zi occupies the north, Wu the south, Mao the east, and You the west — these are the four cardinal points; Chou and Yin sit in the northeast, Chen and Si in the southeast, Wei and Shen in the southwest, Xu and Hai in the northwest. Zi and Wu clash with each other, as do Mao and You, forming opposed pairs along the north-south and east-west axes; the remaining clashing pairs can likewise be located on the Twenty-Four Mountains. When choosing a date to open a door, break ground, or install a stove, tradition examines whether the day branch directly clashes with the shop's sitting mountain, and whether it clashes with the year branch of the principal proprietor. "Clash" here is a rule of the divinatory arts, and does not equate to an actual mishap that is bound to occur.

The Six Harmonies (liuhe), Three Harmonies (sanhe), and Three Meetings (sanhui) are commonly used to observe whether a configuration of forces has come together as a group. For example, if a given year, month, and day form a configuration of the same Five Phase, tradition may regard this as an assisting force if the base chart genuinely needs that qi; but if the base chart is already leaning too far in that direction, then the stronger the harmony, the more caution is called for. One should not treat every appearance of "harmony" as auspicious, nor every appearance of "clash" as inauspicious. Opening an old door, tearing down a wall, working the stove — these actions already carry the image of movement; if construction is then carried out on a date that clashes with the sitting mountain, traditional date selection tends to avoid it. Ordinary cleaning and restocking need not have the shensha blown out of proportion.

3. The Generation and Control of the Heavenly Stems and the Imagery of Date Selection

The Heavenly Stems are used to observe whether the Four Pillars (sizhu) of a chosen date flow properly among themselves. If an opening-day chart has the Five Phases running to extremes — one phase alone flourishing with nothing to remediate it — then even if the almanac page states "suitable for opening a business," this does not mean it actually suits the shop's specific facing, the month, and the principal proprietor all at once. A more complete traditional method first judges flourishing and decline by the monthly command, then examines the generation, control, and pass-through relations among the day master and the various stems and branches, excludes any day or hour that seriously clashes with or controls the sitting mountain, and only then consults the auspicious spirits.

There is also a doctrine of stems combining and transforming (hehua), but whether a combination actually transforms depends on the season, the rootedness of qi, and overall conditions — one cannot simply see two stems in combination and immediately reclassify the Five Phases. The goal of commercial date selection is a combination of timing that is structurally clear, matched to the purpose of the action, and free of any serious clash — not a chase after every auspicious spirit appearing at once. The more conditions one adds, the more likely no usable date can be found at all; hence one must distinguish hard exclusions, preferred conditions, and acceptable conditions.

4. The Compliant Use of Taisui, Suipo, and the Three Killings

The direction of Taisui (the Grand Duke of the year), its opposing suipo (year-breaking) direction, and the year's Three Killings direction are common considerations in traditional date selection for construction and renovation. For a commercial shop, the emphasis falls on "movement": strong actions such as tearing down a wall, breaking ground, moving the main door, altering the stove, or laying a foundation are given far more weight than placing a pot of plants or adjusting a small display item. Where construction is unavoidable, the practical steps — securing approval from the property manager, fire authority, structural engineer, and construction permit — come first; only then does one select a suitable date and time at the level of the arts, and manage the starting point and sequence of the work.

These concepts should not be used to manufacture fear. A direction occupied by Taisui in a given year does not mean that area cannot be used or operated in at all for the whole year, nor does it mean an existing doorway must be sealed. What tradition calls "better still than greatly disturbed" should be handled in light of the nature of the construction, the base chart, and date selection together. Still less should a taboo direction ever be used as grounds to block a safety exit.