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What Do the Four Pillars of Saju Mean?
— year, month, day and hour pillars, their seats and the order to read them

2026-10-30 · Mutal Unnie editorial team

What do the year, month, day and hour pillars mean in Saju?

The four pillars write the year, month, day and hour of your birth as two characters each, one Heavenly Stem on top and one Earthly Branch below, and tradition assigns each pillar a set of people and a stage of life. Four pillars of two characters make eight in all, which is why Korean calls a chart saju palja (四柱八字), “four pillars, eight characters.” In Korean the pillars are yeonju (年柱, year), wolju (月柱, month), ilju (日柱, day) and siju (時柱, hour); you'll also see the year pillar written nyeonju in Korean apps and searches, and both mean the same thing.

A “seat” (gung 宮) is simply the traditional convention of which people a position is matched with. The exact assignments vary a little by book, so use the table as a map of where to look, not as a chart that predicts your family relationships. The order for reading all eight characters together is in How to Read Saju: Complete Guide.

When does each of the four pillars change?

The year pillar changes at Ipchun, the month pillar at each month's solar-term entry time, the day pillar when the day turns over, and the hour pillar every two hours. January 1 and the first of each calendar month play no part.

1. Year pillar: IpchunIf you were born before the exact entry time of Ipchun (立春, the start of spring), you take the previous year's stem-branch pair. The Jeongmi (丁未) year of 2027 begins at 10:46 KST on February 4, 2027, which is 01:46 UTC the same day (Mutal Unnie engine value). The reason is in The Saju new year isn't January 1.
2. Month pillar: each jeolThe month changes at the time of the jeol (節), the one solar term that arrives each month, such as Ipchun, Gyeongchip or Cheongmyeong. It does not change at the mid-month terms (junggi 中氣) such as Usu or Chunbun, the spring equinox.
3. Day pillar: midnight or the Ja hourSome schools start the next day at 11 p.m., when the Ja (子) hour begins; others at midnight. The Mutal Unnie app counts the 11 p.m. hour (the late Ja hour, yajasi) as part of the same day. The difference is laid out in Born at 11 p.m.? The Late and Early Ja Hour.
4. Hour pillar: two-hour blocksThe day is split into twelve two-hour periods. The Mutal Unnie engine's default boundaries fall on the odd hours of the clock, so the O (午, Horse) hour starts at 11:00 and the Mi (未, Sheep) hour at 13:00. Some calculators shift the boundaries 30 minutes later.

If you were born close to one of these boundaries, different manseryeok (Saju calendars) may give you a different pillar, so make sure the pillars match before you compare interpretations. Saju is calculated on the clock time where you were born, so US and UK readers should enter their local birth time, not convert it to UTC; the UTC figure above is only there to help you picture the moment.

What does geunmyohwasil (root, sprout, flower, fruit) mean?

Geunmyohwasil (根苗花實) compares the four pillars to a root, a sprout, a flower and a fruit, reading life as something that grows and bears fruit as you move from the year pillar to the hour pillar. The year pillar is the root, the month pillar the sprout, the day pillar the flower and the hour pillar the fruit.

This metaphor is where the familiar pairing “year pillar for early life, hour pillar for later life” comes from. The age ranges, however, differ by book and by school. Some split life into blocks of roughly 15 years per pillar, others into blocks of around 20.

How do you read a real chart pillar by pillar?

Take someone born at 14:30 on May 15, 1990, entered as Korea time: the chart comes out as a Gyeong-o (庚午) year, Sinsa (辛巳) month, Gyeongjin (庚辰) day and Gyemi (癸未) hour. These are Mutal Unnie engine values for a practice input, not a real person. Naming each character's Ten God from the Day Master, Gyeong Metal (庚金), gives the table below; for the branches, the Ten God is taken from the main hidden stem (bongi 本氣).

This table is reading practice, not a set of sentences that predict a life. Counted on the surface, the chart has Wood 0, Fire 2, Earth 2, Metal 3 and Water 1, so Wood seems to be missing, yet the hidden stems of Jin and Mi each hold an Eul Wood, so we don't declare it absent. The story of this day pillar itself continues in Gyeongjin Day Pillar (庚辰).

Timing works the same way. By root, sprout, flower, fruit, the hour pillar is later life, but the Daeun (大運, 10-year luck cycle) of the very same chart splits by gender. For this example, a man's Daeun runs forward from age 7 (Im-o at 7, Gyemi at 17, Gapsin at 27), and a woman's runs backward from age 3 (Gyeongjin at 3, Gimyo at 13, Muin at 23).

Why is the month pillar called the center of a Saju chart?

Because the month branch (wolji 月支) fixes the season you were born in and tells you which energy is strongest in that season. That's why the month branch has its own name, wollyeong (月令, the “month command”), and a Day Master supported by it is said to have deungnyeong (得令), to have “gained the command.”

In readings that follow the structure-focused (gyeokguk 格局) tradition of the classic Ziping Zhenquan (子平眞詮, Japyeong Jinjeon in Korean), setting the chart's structure from the month branch is the standard starting point. Climate-balancing (johu 調候), where the same Day Master born in winter looks first for warmth and born in summer looks first for moisture, also starts from the month branch. The details are in Climate-Balancing (Johu 調候): Reading Saju by Birth Season.

In the example chart the month branch is Sa (巳), the month that opens summer after Ipha (立夏), so a Gyeong Metal Day Master was born into the hot season. Only two Fire characters show on the surface, but once the season is taken into account, traditional practice reads Fire's strength as greater than its count.

Can I read my Saju without knowing the hour pillar?

Yes. Even with only six characters, the three pillars (samju 三柱), you can still read the Day Master, the season and how the year, month and day relate. The Day Master, the character that stands for you, is set by the date alone (see Day Pillar (日柱) and Day Master). What goes blank is the seat for children and later life that the hour pillar held, plus the two characters' worth of elements it contributed.

Take away the Gyemi hour in the example chart and you're left with Metal 3, Fire 2 and Earth 1, so it looks as if Water is missing too. Yet if you plug in a guessed time, you end up interpreting characters that may not be there, so it's safer to leave the hour blank when you don't know it. Ways to check are in How accurate is Saju if you don't know your birth time?

In what order do you check clashes and combinations between pillars?

Find the stem and branch relationships first, then check whether the day or month branch is involved and how far apart the pillars are, and add luck cycles last. One traditional view holds that pillars sitting right next to each other interact strongly, while characters far apart, such as the year and hour pillars, have a weaker effect.

1. Look at the stemsCheck for stem combinations (Gap-Gi, Eul-Gyeong, Byeong-Sin, Jeong-Im, Mu-Gye) and for stem clashes such as Gap-Gyeong, Eul-Sin, Byeong-Im and Jeong-Gye.
2. Look at the branchesLook for six harmonies (yukhap 六合), three harmonies (samhap 三合) and directional combinations (banghap 方合), and for the clashes Ja-O, Chuk-Mi, In-Sin, Myo-Yu, Jin-Sul and Sa-Hae.
3. Check the seatsSee whether the day branch (your own and your partner's seat) or the month branch (the season) is involved, and whether the pillars are neighbors or far apart.
4. Layer on luck cyclesFinally, add the characters arriving through Daeun and annual luck (seun 歲運), and see which pillar of the birth chart they combine or clash with.

The example chart has no combinations or clashes among its stems. Among its branches, O (year), Sa (month) and Mi (hour) gather into the Sa-O-Mi (巳午未) directional combination of summer, and the year branch O and hour branch Mi form the O-Mi (午未) six harmony. There are no clashes between branches. Mi, though, sits on the far side of the day branch Jin, so how much weight to give this combination varies from reader to reader.

How can I check my four pillars on Mutal Unnie?

Enter your date and time of birth in the free manseryeok calculator on the web to see your four pillars and eight characters right away, without signing up. The calculator lets you switch on daylight saving time and Korea's old standard-time corrections, so if you were born during one of those periods, check whether your pillars stay the same with and without the correction.

The app calculates from the clock time you enter, treated as Korea time (KST), counts the 11 p.m. hour as the same day, and doesn't correct for daylight saving or old standard time automatically. If you were born outside Korea, read how to enter a local birth time in Korean Saju vs. Chinese BaZi vs. Japanese Shichū Suimei first. Once your chart is set, the one-line rhythm for the day and adding events are free, so you can lightly match your Day Master against each day's energy.

Start with today's rhythm

Available on iPhone and Android. Daily rhythm cards and adding events are free. Check the cost before opening a paid reading. Store availability and app language support depend on the listing.