Jia 甲 Wood Day Master: the Tall Tree

甲 (Jia) is yang Wood, pictured as a tall tree growing straight up. When it sits on top of your day pillar, the tradition calls it your day master and reads the whole chart from its point of view.

甲 at a glance

甲 is the first of the ten heavenly stems. Its element is Wood and its polarity is yang, the outward and growing side. Haru's engine gives it the image of "a tall tree growing straight" and describes its nature as "an upright character that wants to grow straight upward".

Its yin partner is 乙, the vine. Both are Wood, but the tree stands on its own trunk while the vine finds a way around things. 甲 is Wood that grows by standing tall.

How the tradition describes the 甲 temperament

The tradition describes 甲 people through the tree. A tree grows in one direction, gives shade, and holds its shape through wind. So the classic portrait is someone steady, principled and willing to take the lead.

• Strengths often named: honesty, a sense of direction, patience with long projects, a protective streak toward others.
• Things to watch, gently: a tree does not bend easily, so the tradition notes a possible stiffness when plans change, and a habit of carrying too much alone.
• A helpful reading: pruning is part of how trees grow. Accepting advice or trimming a plan is not a loss for 甲 but a way to grow straighter.

Which months help 甲

In Haru's engine the month branch decides whether the day master "has the season" (deLing). The rule is simple: the month helps when its element is the day master's own element or the element that produces it. For 甲 that means Wood months and Water months.

So four of the twelve branches help 甲: 寅 and 卯 (Wood, spring) and 亥 and 子 (Water, winter). Note that 辰 is also a spring month, but its element is Earth, so by this rule it does not count. The engine adds 8 points to the support score when the season helps and takes 8 away when it does not, then reads the total as strong (55 or more), weak (40 or less) or balanced.

How 甲 meets the other nine stems

Every other stem becomes one of the ten gods when seen from 甲. The god is fixed by two things: how the other stem's element relates to Wood, and whether its polarity matches. For 甲, the Metal stems 庚 and 辛 become Seven Killings and Direct Officer, the pressure and structure that shape the tree, while the Water stems 壬 and 癸 become the two Resource gods that feed it.

Foods and the reasoning behind them

Haru does not pick foods for a stem alone; it looks at the whole chart. If the chart is read as weak, the engine's rule chooses the element that produces the day master (or the day master's own element). If it is strong or balanced, it chooses whichever of the output, wealth or officer elements is scarcest.

For 甲 the two most typical answers are Water on the support side, because Water produces Wood, and Fire on the release side, because Wood produces Fire and lets a full tree spend its energy. The foods below are the engine's lists for those two elements, grouped by colour and taste as the tradition does. They are ordinary everyday ingredients, not remedies.

Movement and rest

The same two elements carry movement and rest suggestions. On the Water side the engine lists swimming, waterside strolls and slow stretching, with the 亥 hour (21:00-23:00) as a time to lie down early. On the Fire side it lists a light walk in the sun and light jogging, with the 午 hour (11:00-13:00) for a short walk in the midday sun. These are simple lifestyle habits: water feeds the roots, sunlight lets the tree grow.

One stem is not the whole chart

A day master is one character out of eight. Two 甲 people can have very different charts once the month, hour and hidden stems are added, and the tradition always reads the whole picture. Treat this page as a description of how the tradition thinks about Wood that stands tall, not as a label for any person.

Questions

What does "甲 day master" mean?

It means the heavenly stem of your day pillar is 甲. The tradition uses that stem as the "self" of the chart and reads the other seven characters in relation to it.

Is 甲 stronger than 乙?

Not in general. Both are Wood; 甲 is the yang form and 乙 the yin form. Strength is judged per chart from the month branch and the balance of elements, not from the stem alone.

Why does winter count as a helpful season for Wood?

Because the rule counts the element that produces the day master. The winter branches 亥 and 子 are Water, and Water produces Wood, so they are read as nourishing the tree.

Should a 甲 person eat only Water and Fire foods?

No. The lists show how the tradition reasons about balance. A varied everyday diet stays the sensible base; the element lists are a cultural lens, not a rule.

Read next

Traditional Four Pillars (myeongni) and yin-yang five-element interpretation. Not a medical diagnosis or advice.