Four Pillars basics: pillars, elements and the day master
What are the Four Pillars?
The Four Pillars (Bát Tự in Vietnamese) write your birth year, month, day and hour each as one heavenly stem and one earthly branch: four pillars, eight characters. The balance of the five elements — Wood, Fire, Earth, Metal and Water — across these eight characters describes your innate character.
How the pillars are set
- Year pillar: the year changes at Lập Xuân, the start of spring (around 4 February), not at Lunar New Year.
- Month pillar: set by the solar terms (start of spring, waking of insects, clear brightness…), not by the lunar month.
- Day pillar: the 60-day cycle of stems and branches advances one step each day.
- Hour pillar: set by the birth hour and the day stem. We treat births after 11 pm as the Rat hour of the next day.
The ten stems and the day master
The stem of the day pillar is called the day master and stands for you. Each of the ten stems is likened to an image from nature to describe character.
| Stem | Element | As a day master |
|---|---|---|
| 甲 Jia | Wood | A tall tree growing straight: driven and responsible. |
| 乙 Yi | Wood | Grass and vines that root anywhere: flexible and adaptable. |
| 丙 Bing | Fire | The sun lighting the world: bright, frank and passionate. |
| 丁 Ding | Fire | A candle in the dark: warm, attentive and refined. |
| 戊 Wu | Earth | A great mountain: reliable and steady. |
| 己 Ji | Earth | Fertile farmland: nurturing and practical. |
| 庚 Geng | Metal | Raw iron ore: decisive and loyal. |
| 辛 Xin | Metal | Polished precious metal: sharp and exacting. |
| 壬 Ren | Water | A wide river or sea: ambitious and wise. |
| 癸 Gui | Water | Rain and dew: sensitive and intuitive. |
How the elements support and control each other
In the supporting cycle, Wood feeds Fire, Fire makes Earth, Earth bears Metal, Metal carries Water and Water nourishes Wood. In the controlling cycle, Wood controls Earth, Earth controls Water, Water controls Fire, Fire controls Metal and Metal controls Wood. Control is not bad; it keeps things in balance.
Strong and weak day masters
If many characters support the day master (the same element, or elements that feed it), it is called strong; if few, weak. We use a simple rule that counts the month branch twice, and suggest balancing elements: outward-flowing elements for a strong day master, supporting ones for a weak day master.
The ten gods: five kinds of energy
Seen from the day master, the other characters fall into five groups called the ten gods. Whichever group stands out hints at your tendencies.
| Energy | When it stands out |
|---|---|
| Companion (same element as you) | Independent and proud. You are strong with teammates, but also competitive. |
| Output (expression, talent) | Expression and talent stand out. Work where you show yourself through words, writing or skills suits you. |
| Wealth (money, practicality) | Practical and good with money. The type who delivers results. |
| Authority (organisation, duty) | Responsible and rule-minded. You earn recognition inside organisations. |
| Resource (learning, support) | A strong learner and thinker. You tend to receive help and protection. |
For fun and reflection
For centuries people have used the Four Pillars to reflect on themselves. Our readings are generated by rules and meant as a reference only; do not base investment, health or marriage decisions on them.