Fixed and moving parts
The question usually comes with a hidden second half: if it can be changed, how much does a service charge. This page answers the first half with arithmetic and declines the second.
The example chart is 1985-07-04 12:00, male: 乙丑 Yi Chou · 壬午 Ren Wu · 甲辰 Jia Chen · 庚午 Geng Wu. Those eight characters are fixed by the birth moment; nothing that happens afterwards edits them:
| Component | Determined by | Changeable? |
|---|---|---|
| Year and month pillars | which solar node the date falls after | no |
| Day pillar | the continuous day count (rolls at 23:00) | no |
| Hour pillar | the two-hour block of birth | no |
| Day master | the day stem | no |
Above the four pillars sits a second time structure; this site computes 10 steps of it. The example chart runs Backward (ni pai) (yin-stem year (乙) + male → sequence runs backward), starting at 9y 5m 20d:
| Step | Pillar | Stem (ten god) | Branch (ten god) | Ages | Years |
|---|---|---|---|---|---|
| 1 | 辛巳 Xin Si | 辛 Xin 正官 | 巳 Si, Snake 食神 | 10–19 | 1994–2003 |
| 2 | 庚辰 Geng Chen | 庚 Geng 七杀 | 辰 Chen, Dragon 偏财 | 20–29 | 2004–2013 |
| 3 | 己卯 Ji Mao | 己 Ji 正财 | 卯 Mao, Rabbit 劫财 | 30–39 | 2014–2023 |
| 4 | 戊寅 Wu Yin | 戊 Wu 偏财 | 寅 Yin, Tiger 比肩 | 40–49 | 2024–2033 |
| 5 | 丁丑 Ding Chou | 丁 Ding 伤官 | 丑 Chou, Ox 正财 | 50–59 | 2034–2043 |
| 6 | 丙子 Bing Zi | 丙 Bing 食神 | 子 Zi, Rat 正印 | 60–69 | 2044–2053 |
| 7 | 乙亥 Yi Hai | 乙 Yi 劫财 | 亥 Hai, Pig 偏印 | 70–79 | 2054–2063 |
| 8 | 甲戌 Jia Xu | 甲 Jia 比肩 | 戌 Xu, Dog 偏财 | 80–89 | 2064–2073 |
| 9 | 癸酉 Gui You | 癸 Gui 正印 | 酉 You, Rooster 正官 | 90–99 | 2074–2083 |
| 10 | 壬申 Ren Shen | 壬 Ren 偏印 | 申 Shen, Monkey 七杀 | 100–109 | 2084–2093 |
This layer is the part that moves — and it is not optional either. The direction is fixed by the year stem's polarity and the gender, and the annual pillar by the calendar year. What changes is which step you are standing in, not which one you may pick.
The classical literature does contain claims that fate can be changed, roughly of two kinds: that accumulated good conduct changes circumstances, and that dwelling environment and names can adjust them. Neither can be checked by this engine — they produce no recomputable number. This site labels them as traditional readings, neither endorsing nor mocking them. The only thing this page can do is separate fixed from moving: the pillars are fixed; where you stand on the timeline is not.
A note on what this page deliberately does not do: the popular versions of this material assign a fixed personality to each term — one character per branch, one destiny per stage. This site rejects that framing. What is published here is a structural position: which element sits where, on what kind of ground, with which tenants inside. The same term reads differently under a different month command, and no meaningful judgement exists without the other characters of the chart. Where the tradition offers a reading it is labelled as the tradition's; this site's own contribution is that every number and term on this page is computed, versioned and checkable against the methodology page.
These are the questions specific to this page; broader conventions live on the methodology page.
Every enumerable component of ba zi has its own page here. Each page is computed by the same engine and can be checked item by item — none of it is a personality table.