两套体系 · 结构对照
这个比较不是判谁对。比的是各自收进什么、交出什么：一套读行星相对「以春分点为起点」的黄道位置，另一套读「以节气为界」的干支循环。
| 维度 | 西方占星 | 八字 |
|---|---|---|
| 时间粒度 | 日期 + 出生时刻 | 日期 + 出生时刻（时柱需要） |
| 地理位置 | 必需：不给出地点算不出宫位与上升 | 可选：仅用于真太阳时校正（每经度 4 分钟） |
| 分界依据 | 春分点起始的黄道 12 等分 | 节气：太阳黄经每 30° 一个节 |
| 参考量 | 行星与月亮的实际位置 | 干支循环（六十甲子），不由天体实时位置定义 |
A BaZi year pillar turns at lichun, not at New Year and not at lunar new year. Lichun floats between 3 and 5 February. The engine's table covers 201 years (1900–2100); every entry is computed:
| 立春落点 | 年数 | 占比 |
|---|---|---|
| 2 月 3 日 | 39 | 19.4% |
| 2 月 4 日 | 128 | 63.7% |
| 2 月 5 日 | 34 | 16.9% |
Lichun lands on 3 / 4 / 5 February across the 201-year table — 3 possible dates. The western zodiac year turns at the equinox, in the second half of March (this page does not compute astronomical data; that date is given only for contrast), roughly six weeks later. Between mid-January and mid-March the two calendars therefore disagree about which year you belong to.
Both systems have twelve. That is where the wrong correspondences come from. The twelve branches are bounded by solar terms — one branch is one whole month command. The twelve signs are thirty-degree sectors of the ecliptic starting at the equinox.
| 地支 | 换柱节气 | 月序 | 本气 |
|---|---|---|---|
| 子 Zi, Rat | 大雪 Major Snow | 11 | 癸 Gui Water |
| 丑 Chou, Ox | 小寒 Minor Cold | 12 | 己 Ji Earth |
| 寅 Yin, Tiger | 立春 Start of Spring | 1 | 甲 Jia Wood |
| 卯 Mao, Rabbit | 惊蛰 Awakening of Insects | 2 | 乙 Yi Wood |
| 辰 Chen, Dragon | 清明 Clear and Bright | 3 | 戊 Wu Earth |
| 巳 Si, Snake | 立夏 Start of Summer | 4 | 丙 Bing Fire |
| 午 Wu, Horse | 芒种 Grain in Ear | 5 | 丁 Ding Fire |
| 未 Wei, Goat | 小暑 Minor Heat | 6 | 己 Ji Earth |
| 申 Shen, Monkey | 立秋 Start of Autumn | 7 | 庚 Geng Metal |
| 酉 You, Rooster | 白露 White Dew | 8 | 辛 Xin Metal |
| 戌 Xu, Dog | 寒露 Cold Dew | 9 | 戊 Wu Earth |
| 亥 Hai, Pig | 立冬 Start of Winter | 10 | 壬 Ren Water |
There is no "Rat = Aries" mapping. One set of twelve is bounded by nodes, the other by the equinox: they are offset by about six weeks and the offset drifts year to year. Any table that pairs the twelve branches with the twelve signs one-to-one is an invention, and this site does not print it.
| 看得见的东西 | 西方占星 | 八字 |
|---|---|---|
| 骨架 | 行星落座 + 宫位 + 相位 | 四柱干支 + 十神 + 藏干 |
| 主题切分 | 按人生领域分宫（十二宫） | 按柱位分（年/月/日/时）与十神分组 |
| 时间推演 | 行运、次限、太阳返照等 | 大运（十年一步）+ 流年 |
| 本站是否计算 | 否 | 是，且每个数字可核对 |
The usual comparison asks which system is more accurate. This site cannot answer that and will not: it publishes no accuracy rate and no match score against life events. What can be compared is structure — how many inputs, where the cycle turns, which reproducible quantities come out. All three are listed above.
本页刻意不做的事：网上流传的通俗版本会给每个名目指派一套固定性格——一个地支一种人、一个阶段一种命。本站拒绝这种写法。这里发布的是一个结构位置：谁的五行坐在哪里、坐在什么样的地基上、地基里藏着什么。同一个名目在不同的月令之下读法不同；缺少盘中其余各字时，任何有意义的判断都不存在。凡传统给出读法之处，本页标注「此为传统读法」；本站自己的贡献是：页面上的每个数字与名目都由引擎实算、带版本号，可与方法论页逐条对账。
以下是本页独有的问题；更通用的口径问题见方法论页。
本站把八字里可穷举的构件都拆成了独立的页：每一页的事实都由同一个引擎实算，可逐条核对，不是人格对照表。