Mei Hua Yi Shu Method

梅花易數 is arithmetic first. It uses the 先天八卦 numbers — 乾 1, 兌 2, 離 3, 震 4, 巽 5, 坎 6, 艮 7, 坤 8 — and every casting is a division with a remainder on those eight values.

時間起卦 takes the lunar date and hour. The upper trigram is (year-branch number + lunar month + lunar day) mod 8, with a remainder of 0 read as 8. The lower trigram is the same sum plus the hour-branch number, mod 8. The moving line is that same larger sum mod 6, with 0 read as 6. Year and hour branches are numbered from 子 as 1 to 亥 as 12.

數字起卦 replaces the calendar with three numbers: the first mod 8 gives the upper trigram, the second mod 8 the lower, and the sum of all three mod 6 the moving line. Both routes end in the same three values, and everything after that is lookup.

These are the 先天 order, the one Fu Xi is credited with, and it is not the 後天 arrangement that the 洛書 grid and flying-star work use. The two orderings disagree on every number except the centre, which is why a 梅花 casting and a 飛星 chart cannot share a lookup table.

Take 20 November 2026 at 10:00, which is 丙午年十月十二 in the lunar calendar and the 巳 hour, 09:00 to 11:00.

The year branch 午 is 7. The upper seed is 7 + 10 + 12 = 29, and 29 mod 8 = 5, so the upper trigram is 巽. The lower seed adds the hour branch 巳, which is 6: 29 + 6 = 35, and 35 mod 8 = 3, so the lower trigram is 離. The moving line is 35 mod 6 = 5.

巽 above 離 is 風火家人, hexagram 37. A moving fifth line changes the upper trigram from 巽 to 艮, giving 山火賁, hexagram 22. The nuclear hexagram, read from lines 2 to 4 as the lower trigram and 3 to 5 as the upper, is 火水未濟, hexagram 64.

Now the part most retellings skip. The moving line sits in the upper trigram, so the upper trigram is 用 and the lower is 體: 體 is 離 fire, 用 is 巽 wood. Wood feeds fire, so 用生體 — the configuration the rules call favourable.

Then the month is applied. The date falls in 己亥 month, where 水 is 旺, 木 is 相 and 火 is 死. The 用 doing the feeding is 相; the 體 being fed is 死. The support is real and it is thin. That reading only appears if the calendar is carried into the judgement, which is why 卦氣 belongs to the method rather than to commentary.

The pair is read by element relation, not by hexagram number. 用生體 is the favourable case; 體生用 drains the asker; 比和 — same element on both sides — is stable but static; 體克用 costs effort and usually succeeds; 用克體 is the case the tradition treats as adverse.

The three hexagrams are not three answers to one question. 本卦 is the situation as posed, 互卦 is what is already inside it — hidden, running underneath — and 變卦 is what it turns into once the moving line has moved. The standard reading walks them in that order.

The nuclear hexagram is built only from lines 2 to 5, which means it ignores the two lines that the changing line can reach in one step. That is the point: 互卦 describes the interior that does not depend on which line moves, so it stays the same regardless of the casting's trigger.

Conflicts between the three are common and are the most informative part of a reading. In the casting above, 家人 is a hexagram about the ordering of a household, 未濟 is about a crossing that has not completed, and 賁 is about ornament rather than substance. A situation that reads as orderly on the surface, unfinished underneath, and decorative after the change is a description with some bite — and no single hexagram in the set says it alone.

The method is attributed to 邵雍 (1011–1077), and the name comes from his 梅花 poem. The received 《梅花易數》 text, however, is generally dated to the Ming — compiled and expanded several centuries after his death. The book is not a Song autograph, and the phrase 'Shao Yong's method' is a lineage claim rather than a bibliographic fact.

This matters for how the method is described. It is a Ming-era manual systematising an earlier divinatory habit of deriving a hexagram from a number or a moment, not a treatise whose every rule can be traced to one Song scholar. The arithmetic is old; the codification is not.

The formula takes the clock, not the question. Two people casting in the same minute receive the same hexagram regardless of what they asked, and one person casting the same question twice in one 時辰 receives the same answer twice. That is a structural property, and it is the strongest argument against reading the output as a reply.

What the method does do is force a second description. The 卦辭 and 象 are short, dense and fixed; applying them to a situation produces distinctions the asker had not been making. That is a real effect and it does not require the hexagram to know anything.

A casting yields no probabilities and no dates. The only checkable claim it makes is internal consistency: whether 體用, the nuclear hexagram and the changed hexagram point the same way, and whether the 卦氣 supports the relation. When they conflict — as they partly do in the example above, where the relation is favourable and the season is not — the honest reading is that they conflict.

That is a lower ceiling than the popular version promises, and it is the ceiling the method actually has. Used inside it, the casting is a way of making yourself state a situation in terms you did not choose, which is occasionally worth more than the answer you were hoping for.