The ten stems: element and polarity
| 天干Stem | 甲Jia | 乙Yi | 丙Bing | 丁Ding | 戊Wu | 己Ji | 庚Geng | 辛Xin | 壬Ren | 癸Gui |
|---|---|---|---|---|---|---|---|---|---|---|
| 五行Element | 木 | 木 | 火 | 火 | 土 | 土 | 金 | 金 | 水 | 水 |
| 阴阳Polarity | 阳Yang | 阴Yin | 阳Yang | 阴Yin | 阳Yang | 阴Yin | 阳Yang | 阴Yin | 阳Yang | 阴Yin |
规律：每两个天干共享一种五行，阳干在前、阴干在后，按「木火土金水」顺序轮转两轮。Pattern: each pair of stems shares one element - yang before yin - cycling through wood, fire, earth, metal and water twice.
The twelve branches: element, animal and hour
| 地支Branch | 五行Element | 阴阳Polarity | 生肖Animal | 时辰Hour |
|---|---|---|---|---|
| 子 | 水 | 阳Yang | 鼠Rat | 23:00–01:00 |
| 丑 | 土 | 阴Yin | 牛Ox | 01:00–03:00 |
| 寅 | 木 | 阳Yang | 虎Tiger | 03:00–05:00 |
| 卯 | 木 | 阴Yin | 兔Rabbit | 05:00–07:00 |
| 辰 | 土 | 阳Yang | 龙Dragon | 07:00–09:00 |
| 巳 | 火 | 阴Yin | 蛇Snake | 09:00–11:00 |
| 午 | 火 | 阳Yang | 马Horse | 11:00–13:00 |
| 未 | 土 | 阴Yin | 羊Goat | 13:00–15:00 |
| 申 | 金 | 阳Yang | 猴Monkey | 15:00–17:00 |
| 酉 | 金 | 阴Yin | 鸡Rooster | 17:00–19:00 |
| 戌 | 土 | 阳Yang | 狗Dog | 19:00–21:00 |
| 亥 | 水 | 阴Yin | 猪Pig | 21:00–23:00 |
四个土支（辰、戌、丑、未）分布在四季末尾，旧称「四库」或「四墓」，是季节交替的过渡位置。时辰表为纯历法知识，本页不涉及任何吉凶推断。The four earth branches (chen, xu, chou, wei) sit at the close of each season - traditionally called the four "storehouses", the transition points between seasons. The hour table is pure calendrical knowledge; this page makes no fortune claims.
Generating and overcoming cycles
| 类型Type | 口诀Mnemonic | 循环Cycle |
|---|---|---|
| 相生Generating | 木生火、火生土、土生金、金生水、水生木Wood feeds fire, fire makes earth, earth bears metal, metal collects water, water nourishes wood | 木 → 火 → 土 → 金 → 水 → 木 |
| 相克Overcoming | 木克土、土克水、水克火、火克金、金克木Wood parts earth, earth dams water, water quenches fire, fire melts metal, metal chops wood | 木 → 土 → 水 → 火 → 金 → 木 |
相生是邻位相连、相克是隔位相对：两个循环各自首尾相接，构成传统体系里最基本的平衡模型。这些对应是文化符号间的逻辑关系，如同坐标系定义，不涉及任何人事吉凶。Generation links neighbours, overcoming links next-neighbours: two cycles, each closing on itself, form the basic balance model of the traditional system. These are logical relations between symbols, like coordinate definitions, and say nothing about personal fortune.
How elements enter the stem-branch system
The stems and branches are an ordinal system for dating years and days: ten stems and twelve branches combine into sixty pairs, the sexagenary cycle. The elements add a classification layer - every stem and branch has a fixed element and polarity (jiazi = yang wood + yang water, yichou = yin wood + yin earth). Each of the sixty pairs also carries a "nayin" element name (jiazi/yichou is "metal in the sea"), thirty names in all, a finer traditional labelling; the full list is in the sexagenary tool, which also counts the elements of any birth date.
Related references and tools
要查六十甲子与纳音，用 六十甲子对照；要查生肖年份与关系，用 生肖年份对照表 与 生肖关系对照表；要查任意日期的干支，用 农历万年历。
FAQ
Why are there four earth branches?
The twelve branches map to twelve months, three per season. If each season took exactly three branches of wood, fire, metal and water, earth would have nowhere to go; the traditional solution gives the last month of each season to earth (chen, xu, chou, wei), making earth the transition between seasons - hence their special status as the four "storehouses".
Are the five elements the same as wood, fire and the rest as materials?
The same five characters are used, but as classificatory symbols rather than substances - "wood" stands for a generating kind of property, "metal" for a contracting kind. Reading them as labels for five kinds of process fits their use in the calendar and the stem-branch system far better than reading them as five materials.
How are the elements of a birth chart counted?
The year, month, day and hour of birth each give a stem-branch pair (the four pillars, eight characters in all), each with a fixed element. Counting the elements across the eight characters is what tradition calls "what the five elements lack" - a purely numerical result our sexagenary tool computes automatically; what it is said to mean belongs to folk interpretation, and this site provides only the objective count.