BAZI KNOWLEDGE BASE
One-Decade Enclosure: Endpoints and the Pillars between Them
One-Decade Enclosure uses the endpoints of a ten-pillar decade, such as Jia-Zi through Gui-You. The following compact phrase can be read as placing Month, Day and Fetus within the Year/Hour endpoints. The subject is the relationship between endpoints and intervening positions, not ten extra pillars in a birth chart.
What are the endpoints of the six decades?
Each decade begins with Jia and ends with Gui, nine steps later. The source directly illustrates the Jia-Zi and Jia-Yin decades; the other four pairs follow from the cycle.
| Decade | First pillar | Last pillar |
|---|---|---|
| Jia-Zi | Jia-Zi (甲子) | Gui-You (癸酉) |
| Jia-Xu | Jia-Xu (甲戌) | Gui-Wei (癸未) |
| Jia-Shen | Jia-Shen (甲申) | Gui-Si (癸巳) |
| Jia-Wu | Jia-Wu (甲午) | Gui-Mao (癸卯) |
| Jia-Chen | Jia-Chen (甲辰) | Gui-Chou (癸丑) |
| Jia-Yin | Jia-Yin (甲寅) | Gui-Hai (癸亥) |
How can the endpoints and middle positions be checked in a chart?
The synthetic chart Jia-Zi, Bing-Yin, Ji-Si, Gui-You passes calendar-pair checks. In the Jia-Zi decade its Year, Month, Day and Hour occupy positions 1, 3, 6 and 10, placing Month and Day between Year and Hour. This illustrates that layer, not a complete verdict or dated birth.
| Actual position | Pillar | Place in decade |
|---|---|---|
| Year | Jia-Zi (甲子) | 1 |
| Month | Bing-Yin (丙寅) | 3 |
| Day | Ji-Si (己巳) | 6 |
| Hour | Gui-You (癸酉) | 10 |
If the four pillars fit, must the fetal pillar fit too?
No. Under the common rule of advancing the month stem (the upper symbol in the birth-month column) by one and branch by three, Bing-Yin gives Ding-Si Fetus. Ding-Si is in the Jia-Yin decade, outside Jia-Zi. The example therefore cannot establish a five-position enclosure.
This fetal pillar is a traditional derived position, not an observed conception date. Another derivation needs its method and result stated before containment is checked.
What does enclosure help explain, and what does it not establish?
Enclosure becomes understandable once endpoints and intervening positions are shown. Unused members such as Yi-Chou or Ding-Mao cannot be inserted into natal hidden-stem (an additional element symbol traditionally assigned inside a lower chart symbol) or Ten-God calculations merely because they belong to the decade.
The passage also mentions four, five or seven positions and Dayan terminology without fully explaining their selection. Useful intervening relations and other support remain separate questions; matching endpoints alone establishes no social rank.
Continue reading
- Special patterns overview
Distinguish local configurations, whole-chart methods and source cases.
- Five Positions in One Decade: check all five memberships
Compare enclosure with five-position membership.
- Officer and actual authority relations
Return the placement to the month and whole chart.