TL;DR: The Đinh Mùi year combines the stem Đinh (yin Fire) and the branch Mùi (yin Earth); in Bát Tự the Đinh Mùi year pillar begins at Start of Spring on 4 February 2027, not at Tết on 6 February 2027. Under the Ten Gods rule, Đinh is the Direct Officer for a Canh Day Master, the Seven Killings for Tân, the Direct Resource for Mậu and the Hurting Officer for Giáp. Mùi combines with Ngọ, forms a Three Harmony with Hợi and Mão, clashes with Sửu, harms Tý and forms the Three Punishments with Sửu and Tuất. These are lookups under the art's rules, not verdicts.
What is the Đinh Mùi year 2027 in the stem-branch system?
Đinh Mùi is one pair in the 60-year stem-branch cycle: the stem Đinh is Fire, yin; the branch Mùi is Earth, yin, corresponding to the sixth lunar month. The lunar year Đinh Mùi begins at Tết on 6 February 2027 and ends on 25 January 2028.
Bát Tự does not change the year at Tết but at the solar term Start of Spring (Lập Xuân). Start of Spring 2027 falls at 08:42 on 4 February 2027, and Start of Spring 2028 at 14:30 on 4 February 2028 (Vietnam time). People born between those two moments have Đinh Mùi as their year pillar; for everyone else, Đinh Mùi is the passing year (lưu niên) moving through the chart.
Which Ten God does the stem Đinh become for each of the ten Day Masters?
Under the Ten Gods rule of Bát Tự, the five-phase relation between the Day Master and the stem Đinh gives the type of relation, and whether their yin-yang is the same or different gives the "direct" or "indirect" name.
| Day Master | Phase, yin-yang | Relation to Đinh (yin Fire) | Ten God of the stem Đinh |
|---|---|---|---|
| Giáp | yang Wood | Day Master produces Đinh, different polarity | Hurting Officer (Thương Quan) |
| Ất | yin Wood | Day Master produces Đinh, same polarity | Eating God (Thực Thần) |
| Bính | yang Fire | Same phase, different polarity | Rob Wealth (Kiếp Tài) |
| Đinh | yin Fire | Same phase, same polarity | Friend (Tỷ Kiên) |
| Mậu | yang Earth | Đinh produces the Day Master, different polarity | Direct Resource (Chính Ấn) |
| Kỷ | yin Earth | Đinh produces the Day Master, same polarity | Indirect Resource (Thiên Ấn) |
| Canh | yang Metal | Đinh controls the Day Master, different polarity | Direct Officer (Chính Quan) |
| Tân | yin Metal | Đinh controls the Day Master, same polarity | Seven Killings (Thất Sát) |
| Nhâm | yang Water | Day Master controls Đinh, different polarity | Direct Wealth (Chính Tài) |
| Quý | yin Water | Day Master controls Đinh, same polarity | Indirect Wealth (Thiên Tài) |
A Ten God name only says where the stem Đinh stands relative to the Day Master. It does not by itself say whether the year is good or bad.
How does the branch Mùi combine, clash, punish or harm other branches?
According to the branch rules in the Sanming Tonghui and later Bát Tự books:
- Ngọ and Mùi form a Six Combination: the book says Ngọ is the first yang and Mùi the second yin, one and two make three, so the two combine[2].
- Hợi, Mão and Mùi form a Three Harmony: Mùi belongs to the triad with Hợi and Mão.
- Sửu and Mùi clash: they stand seven places apart; the Sanming Tonghui says the branches take the seventh position as a clash[4]. Thiệu Vĩ Hoa explains that the Kỷ Earth and Đinh Fire hidden in Mùi counter-attack the Quý Water and Tân Metal hidden in Sửu[1].
- Tý and Mùi harm each other: the book says Mùi is flourishing Earth and Hợi-Tý flourishing Water, a harm between powerful houses[3].
- Sửu, Tuất and Mùi form the Three Punishments: the book calls it the "punishment of relying on power", counted from Sửu forward to Tuất and from Tuất forward to Mùi[5].
| Branch in the chart | Relation to the passing year Mùi |
|---|---|
| Ngọ | Six Combination |
| Hợi, Mão | Three Harmony |
| Sửu | Clash, Three Punishments |
| Tuất | Three Punishments |
| Tý | Six Harm |
| Thìn | Same group of the four storehouses Thìn Tuất Sửu Mùi |
Why should the lookup tables not be read as verdicts?
The tables describe relations; they are not scorecards. In Bát Tự reasoning, the same Direct Officer may be seen as favourable for a strong Day Master and as pressure for a weak one; the conclusion depends on the whole chart, the other pillars and the current luck period.
These are rules of a traditional divinatory art, not verified by research. This article only presents how the books calculate; it is not meant for decisions about study, work, money or health.
Where do the books disagree?
There are at least two points where the books differ. First, whether the Sửu Tuất Mùi punishment needs all three branches or only two. Second, which phase the branch Mùi stores and when the storehouse "opens": some books require a clash, others say the passing year is enough.
When reading any reading of the Đinh Mùi year, ask which convention the reader follows on these two points.
Nhật Nguyệt's suggestion: how to look up the Đinh Mùi year for your own chart?
First, take the stem of your birth day as the Day Master and look it up in the Ten Gods table above. Then compare the four branches of your chart with the Mùi relations table: note any Ngọ, Hợi, Mão, Sửu, Tuất or Tý and its relation.
The result is a description of the mechanism under the art's rules, not a prediction for 2027.
