Rising Hour Method: Deriving Hour Stems from Day Stem

日上起时法 is the method by which the heavenly stem of the hour pillar is derived from the heavenly stem of the day pillar. The earthly branch of the hour pillar is fixed by the clock time of birth, while the heavenly stem must be computed from the day stem. The mnemonic verse for this procedure is called 五鼠遁.

口诀的六句怎么念

The verse reads:

甲己还加甲， 乙庚丙作初， 丙辛从戊起， 丁壬庚子居， 戊癸何方发， 壬子是真途。

In plain terms, the first line states that for 甲 day and 己 day, the stem of the 子 hour is 甲. The second line states that for 乙 day and 庚 day, the 子 hour begins with 丙. The third line states that for 丙 day and 辛 day, the 子 hour begins with 戊. The fourth line states that for 丁 day and 壬 day, the 子 hour is 庚子. The fifth and sixth lines state that for 戊 day and 癸 day, the correct starting point of the 子 hour is 壬.

The verse is recited as six lines, with the final line serving to complete the fifth line and identify 壬子 as the 子 hour for 戊 and 癸 day stems.

五组日干各自对应的子时天干

The correspondence used by this site’s engine is as follows:

• 甲 day and 己 day begin the 子 hour with 甲子.
• 乙 day and 庚 day begin the 子 hour with 丙子.
• 丙 day and 辛 day begin the 子 hour with 戊子.
• 丁 day and 壬 day begin the 子 hour with 庚子.
• 戊 day and 癸 day begin the 子 hour with 壬子.

The ten day stems are grouped into five pairs, each pair sharing one starting stem for the 子 hour. The pairing is not arbitrary but follows the order of the ten heavenly stems and the five combinations used in the verse.

定了子时之后怎么顺推

Once the 子 hour stem has been determined, the remaining hour pillars are produced by moving forward through the sexagenary cycle. Each successive hour advances both the heavenly stem and the earthly branch by one position.

For example, if the 子 hour is 甲子, then the 丑 hour is 乙丑, the 寅 hour is 丙寅, and so on through the twelve double-hours of the day. The sequence follows the standard order of the sixty 干支 pairs, beginning from the determined 子 hour and continuing without interruption. Because the hour pillar is a full 干支 pair, the earth branch changes according to the clock hour, and the heaven stem changes in step with it.

The forward movement is applied in order of the twelve hour branches: 子，丑，寅，卯，辰，巳，午，未，申，酉，戌，亥. Each step corresponds to one 时辰, the traditional two-hour period.

为什么称作五鼠遁

The name 五鼠遁 comes from two elements. 子, the first of the twelve earthly branches, is associated with the Rat. The verse gives the heavenly stem for the 子 hour, and 子 is the Rat branch. Since the ten day stems are arranged into five pairs, the verse produces five possible starting stems for the 子 hour, one for each pair of day stems. Thus the method is called 五鼠遁, meaning the five Rat starting points.

The word 遁 here refers to the derivation or movement from the day stem to the hour stem, specifically to the stem of the 子 hour. The five groups of day stems are the five Rats, each with a different stem, from which the other hour stems are then generated.

用这条口诀最容易错的两处

The first point of error is the input to the verse. The mnemonic takes the stem of the day pillar as its starting point, not the day of the week or the solar date. In practice, this means the day stem must first be obtained correctly from the day pillar. A common mistake is to use the day stem of the calendar date of birth without checking the time of birth against the boundary of the day. For persons born after 23:00, the day pillar has already advanced to the next day, and the hour calculation must use the day stem of that next day. If the person is born after 23:00 but the practitioner still uses the previous day’s stem, the resulting hour pillar will be wrong.

The second point of error concerns the hour itself. If the clock time of birth is unknown or unclear, the hour pillar cannot be determined. The hour branch is fixed by the time of birth, and without that branch the hour stem cannot be meaningfully derived from the day stem. When the hour pillar is missing, the associated ten gods based on the hour stem and the parts of the spirit-star assessments that depend on the hour branch are also unavailable. The absence of the hour pillar therefore affects more than the hour column alone.