第五讲 时辰干支

Lecture 5: Hourly Heavenly Stem and Earthly Branch

Overall Paraphrase

This chapter enters the core operational phase of Shi Jia Qi Men (Hour-based Odd Gate) — the determination of the Hourly Heavenly Stem and Earthly Branch. Although it is called "Shi Jia Qi Men," when initially selecting which living board (ju) to use, the basis is the solar terms and day stem-branch (as covered in the previous four lectures), without yet involving the hour. However, once a particular board has been determined based on solar terms and the day stem-branch, the living board must then be rotated according to the precise hour (zheng shi). At this point, the primary basis is the stem and branch of the current hour.

The earthly branch of the hour is relatively straightforward: it directly corresponds to the "precise hour" of the divination moment and can be calculated using Beijing Time on a clock (with conversion to local time required: Local Time = Beijing Time − (Local Sunrise Time − Beijing Sunrise Time)).

The correspondence between the twelve double-hours and clock times is as follows:

Knowing only the earthly branch of the hour is insufficient for rotating the living board; the heavenly stem of the hour must also be deduced simultaneously. The hourly stem can be derived jointly from the day's heavenly stem and the hourly earthly branch.

Core Concepts 💡

• The two-step logic of Shi Jia Qi Men: The first step, "fixing the board," relies on solar terms and the day stem-branch; the second step, "rotating the board," depends on the hourly stem-branch of the precise hour. Both are indispensable — the hour is the activation key that sets the Qi Men living board into motion.
• The concept of precise hour (zheng shi): Qi Men divination is based on the "precise hour" — the actual moment when an event occurs (or the moment of divination) — rather than an arbitrarily chosen time. The precise hour represents the cross-section of heaven and earth's energy at that instant.
• The importance of local time: In ancient times, the sundial was used to measure time, essentially representing true solar time. Modern use of Beijing Time (standard time at 120°E longitude) must be converted to local actual time; otherwise, the hourly earthly branch may be inaccurate, causing the entire living board rotation to be miscalibrated.
• The dependency of hourly stem derivation: The hourly stem does not exist independently; it is jointly determined by two variables — the "day stem" and the "hourly branch" — this is the principle behind the Five Rat Hidden (Wu Shu Dun) method of deriving hour stem from day stem.

Modern Interpretation 🌟

• From "clock time" to "natural time": Contemporary people are accustomed to standardized time-zone time, but Qi Men Dun Jia is rooted in a worldview of "human-heaven resonance," emphasizing the time determined by the sun's actual position. This means that even at the same moment, the corresponding Qi Men hour may differ between Ürümqi and Beijing. Although the formula for converting local time can be more precisely replaced in modern times by using longitude (Local Time = Beijing Time + (Local Longitude − 120°) × 4 minutes), the ancients' approach of correcting by sunrise time differences is entirely reasonable.
• The twelve-hour time framework: Dividing a 24-hour day into 12 segments of 2 hours each is not merely a time-keeping unit; it represents the rhythm of yin-yang and five-element energy flow. At Zi hour, one yang begins to arise; at Wu hour, yang peaks and yin emerges; Mao and You mark the points of yin-yang equilibrium. Choosing different hours to rotate the living board means capturing different energy configurations.
• The practical significance of hourly stem calculation: The hourly stem is not an isolated symbol; it represents the essential character of the event at hand. For example, if the hourly stem is Jia (concealed under the Zhi Fu), it indicates the dominant force of the matter; if the hourly stem is overcome, progress is hindered. The day stem represents the "person," while the hourly stem represents the "affair"; the generation-overcoming relationship between the two is one of the core threads in Qi Men divination judgment.
• A demystified perspective: The hour stem-branch system is essentially the ancients' symbolic modeling of the correlation between temporal periodicity and event associations. Its value lies not in "determining" anything, but in providing a coordinate system for observing the energy state of things at specific temporal nodes.

Practical Value ⚡

• Time selection for decisions: Choosing favorable hours and avoiding unfavorable ones for important affairs (contract signing, business openings, travel, negotiations). For example, avoid critical actions during the "Five Non-Encounter Hours" (when the hourly stem overcomes the day stem).
• Divination calibration: In actual Qi Men divination, one must first convert "Beijing Time" to "local true time" before determining the hourly earthly branch; otherwise, the entire board will be wrong. This is the first checkpoint at the operational level.
• Rapid calculation of hourly stem: With proficient use of the Five Rat Hidden mnemonic (see "Related Knowledge"), one can quickly derive the hourly stem from the day stem within seconds, without consulting tables. This is fundamental skill for Qi Men practitioners.
• Time management: The energy rhythm of the twelve double-hours can assist modern people in arranging their daily routines. For example, Zi hour (23:00–01:00) is suitable for rest and nurturing yin; Wu hour (11:00–13:00) has the strongest yang energy and is appropriate for moderate activity. This is consistent with traditional Chinese health preservation practices.
• Review and validation: After each divination, record the hour stem-branch used; review afterward to verify whether the relationship between the hourly stem and day stem aligns with how events actually unfolded, gradually building a personal empirical database.

Philosophical Reflections 🤔

• Time is not a homogeneous container: In modern physics, time is viewed as a uniformly flowing dimension; whereas in the Qi Men Dun Jia worldview, each double-hour has its distinctive qualitative nature. The "one yang arising" at Zi hour and "yang peaking while yin emerges" at Wu hour are not merely observations of nature by the ancients — they represent a philosophical stance regarding time as a living process rather than an abstract coordinate.
• Precise hour and the "present moment": Qi Men emphasizes the precise hour — this very instant. This tacitly aligns with the philosophical proposition of "living in the present" — the past is gone, the future has not yet arrived, and only the present is the true field where energy converges and decisions materialize. What the Qi Men board captures is precisely the "cosmic slice" of the present moment.
• The dialectic of day stem and hourly stem: The day stem is "self" (the subject), the hourly stem is "the matter" (the object); their generation-overcoming relationship maps the dynamic tension between subject and object, person and environment. When the hourly stem is generated by the day stem (I generate), the matter exhausts one's energy; when the hourly stem generates the day stem (generates me), the matter resolves effortlessly. This is relational thinking, emphasizing that things exist within relational networks rather than in isolation.
• Circularity and linearity in the twelve earthly branches: The twelve earthly branches exhibit both the cyclical periodicity of recurrence (day after day) and, through differing heavenly stems, uniquely irrepeatable days and hours (the rotation of the sixty jiazi). This reveals the coexistence of cyclicality and irreversibility in the nature of time — just as history both repeats certain patterns and never truly re-enacts itself.

Related Knowledge

Related Concepts

• Five Rat Hidden (Wu Shu Dun; deriving hour stem from day stem): The fundamental rule for deriving the hourly stem from the day stem. The mnemonic is as follows:
  • Jia and Ji: start with Jia — for Jia day or Ji day, the Zi hour begins with Jia Zi
  • Yi and Geng: Bing comes first — for Yi day or Geng day, the Zi hour begins with Bing Zi
  • Bing and Xin: start from Wu — for Bing day or Xin day, the Zi hour begins with Wu Zi
  • Ding and Ren: Geng Zi resides — for Ding day or Ren day, the Zi hour begins with Geng Zi
  • Wu and Gui: where does it originate? Ren Zi is the true path — for Wu day or Gui day, the Zi hour begins with Ren Zi
• True solar time: Time determined by the sun's actual position, which contains discrepancies from clock time (mean solar time). The "precise hour" used in Qi Men Dun Jia is essentially true solar time.
• Zhi Fu (Value Symbol) and Zhi Shi (Value Envoy): After rotating the living board, the star where the hourly stem resides is the Zhi Fu, and the door where it resides is the Zhi Shi; both govern the entire board and stand at the core of Qi Men judgment.
• Five Non-Encounter Hours: Hours in which the hourly stem overcomes the day stem with yang overcoming yang or yin overcoming yin; the ancient method regards these as greatly inauspicious, recommending stillness over action.

Further Reading

• The first four lectures of the Qi Men Dun Jia Tutorial: the method of fixing boards by solar terms and day stem-branch
• Song of the Old Fisherman by the Misty Waves (Yan Bo Diao Sou Ge): the foundational ode of Qi Men Dun Jia, which details the Zhi Fu, Zhi Shi, and the method of rotating the living board
• Complete Compendium of Qi Men Dun Jia (Qi Men Dun Jia Mi Ji Da Quan): systematic discourse on the generation-overcoming relationship between hourly and day stems
• Zeng Shan Bu Yi: although a classic on six-line (liu yao) divination, its discussions on the selection and use of "hours" can be cross-referenced with Qi Men

Modern Research

• Contemporary research on true solar time indicates that for every 1° of longitude deviation, the time difference is approximately 4 minutes. China's east-west span is about 62°, so the difference between Beijing Time as "standard time" and true solar time in western regions may exceed 2 hours — ample evidence that local time conversion is an indispensable step in Qi Men practice.
• Some researchers have correlated the waxing and waning of yin and yang across the twelve double-hours with human circadian rhythms (biological clocks), finding that from Zi to Mao hours (23:00–07:00) coincides with the peak of melatonin secretion, while Wu hour (11:00–13:00) corresponds to the physiological post-lunch dip; a certain correspondence exists between the two.
• Statistical research on the relationship between hour stem-branch and event outcomes remains exploratory, lacking rigorous double-blind experimental data; an open and empirical attitude is advised — neither superstitious adherence nor outright dismissal of its reference value as a symbolic experiential system.