The Four Pillars: Year, Month, Day and Hour

Year pillar (연주): the year you were born

The pillar of the year you were born. It stands for ancestors and childhood. The lower character of the year pillar is what we call the zodiac animal (띠). In saju (Four Pillars astrology) the year changes at Ipchun (입춘, the Start of Spring, around 4 February in the solar calendar), not on 1 January or on Seollal (Lunar New Year). So someone born in January 2001 is not a Snake of 2001 but a Dragon (庚辰) of 2000.

Month pillar (월주): the month you were born

The pillar of the month you were born. It stands for parents and the social environment. The month also changes not on the first day of the lunar month but at twelve solar terms such as Ipchun (입춘), Gyeongchip (insects awaken, 경칩) and Cheongmyeong (clear and bright, 청명). The lower character of the month pillar (the month branch, 월지) tells the season of birth, so it carries the most weight when judging whether the Day Master's energy is strong or weak.

Day pillar (일주): the day you were born

The pillar of the day you were born (two characters, upper and lower). It is the place for you and for your spouse. The upper character, the Day Master (일간), stands for "you" in the whole chart, and the lower character, the day branch (일지), is taken as the spouse's place. This pillar is the starting point for reading a saju.

Hour pillar (시주): the hour you were born

The pillar of the hour you were born. It stands for children and later life. The day is divided into twelve slots of two hours each. If the hour of birth is not known, the chart is read without the hour pillar, with six characters, and the reading becomes less detailed in proportion to the characters lost. In that case Halmeoni also avoids saying anything that relies on the hour pillar.

The places of the pillars and how Halmeoni uses them

The meanings of the positions are correspondences from traditional readings and differ slightly from school to school. Halmeoni uses them only as clues for reading, not as grounds for firm statements.

Example: setting the pillars one by one

Let us follow how the four pillars are set for someone born in Seoul at 00:50 on 25 August 2001. The solar term times are the astronomical values Halmeoni uses, converted to Korean time.

The upper characters of the month and hour follow rules

The lower characters of the month and hour pillars are set by the solar terms and the time of day, and their upper characters follow the year stem and the Day Master respectively. In a year whose year stem is 甲 or 己, the 寅 month starts with 丙寅, and after that it moves forward one step a month in the order of the 60 gapja. The hour pillar works the same way: on a day whose Day Master is 甲 or 己, the Ja hour starts with 甲子.

The example chart is a 辛 year, so its 寅 month is 庚寅, and the 申 month is six steps after the 寅 month; counting 庚寅·辛卯·壬辰·癸巳·甲午·乙未·丙申 gives 丙申. The Day Master is 庚, so the Ja hour is 丙子. Thanks to this rule, once you know the year stem and the Day Master, you can count out the upper characters of the month and hour without looking at a table.

Adjusting the hour of birth

A saju is read not by clock time but by time based on the sun at the place of birth. Korea Standard Time is set to 135°E, a longitude on the Japan side, so the clock runs ahead of the real sun by about 32 minutes in Seoul and about 24 minutes in Busan. The time is therefore corrected by the longitude of the city of birth, which is called the longitude correction (경도 보정). This is also why Halmeoni asks where you were born.

Korea used daylight saving time during the summers of 1948–1951, 1955–1960 and 1987–1988. If you were born in those periods, the clock had been set one hour ahead, so that is corrected as well.

11 pm to 1 am (the Ja hour, 자시)

The Ja hour (자시) straddles the change of date, so there are two ways of handling it. One counts it as the next day already from 23:00; the other keeps it as the same day until midnight and only reads the hour character as 子 (the approach that separates the Night Ja hour 야자시 from the Early Ja hour 조자시). By default Halmeoni calculates with the day changing at midnight. If you were born in this hour, the day pillar may come out differently from other manseryeok (perpetual calendar).

How things change if you are born on a boundary

Calculating with Halmeoni while shifting the time a little before and after the example chart shows clearly which pillar changes when (all born in Seoul).

In the first two rows the zodiac animal changes with one day's difference, and in the third and fourth rows the month changes within the same day. The year and month pillars compare the solar term time with the moment of birth, so they split to the minute regardless of the longitude correction. In the fifth row it is the 25th by the clock, but the corrected time is the night of the 24th, so Halmeoni uses the 24th's day pillar, 己未. The hour pillar follows the next day's Day Master 庚 and is 丙子. In a manseryeok using the whole-Ja-hour method (정자시), which changes the day at 23:00, the same time comes out as the 庚申 day of the 25th. When the Day Master changes from 庚 to 己, all the Ten Gods change, so if you were born at a boundary time like this, check the standard first.

Common misconceptions

• The zodiac animal changes at Seollal: the saju animal changes at Ipchun. Someone born on 3 February 2001 was born after Seollal (24 January) but before Ipchun, so they are a Dragon (庚辰).
• The month changes on the first day of the lunar month: the saju month changes at the twelve solar terms. A lunar date and the saju month can be out by more than half a month.
• The hour pillar matters less: the hour pillar accounts for 25 of the 100 points in Halmeoni's strength calculation. In the example chart, too, removing the hour pillar changes the strength score from 55 to 73.

Frequently asked questions

• I was born at 00:30 and my day pillar differs from other manseryeok. If you were born in Seoul, the corrected time is still in the 23:00 hour of the previous day, so Halmeoni uses the previous day's day pillar. Places that use the whole-Ja-hour method (정자시) use the next day's day pillar.
• I was born on a day with a solar term, but I don't know the time. If the time is unknown, the year and month pillars are set using noon of that day, so the result may be wrong. On such days Halmeoni tells you, "Your birth date falls on a solar term."
• Are the pillars set differently if I was born abroad? The year and month pillars are compared with solar terms, which fall at the same moment everywhere in the world, and the day and hour pillars are set by solar time at the place of birth. The rules are the same.