Why does the starting age of the Luck Pillars differ between almanac apps?

The starting age is found by dividing the number of days from the birthday to the next (or previous) solar term by 3. It can differ by 1 depending on whether the solar term is read by date or by exact time, and whether the remainder is rounded.

How do I enter a birth outside Korea?

Enter the local clock time and the city of birth. Sajunyang's birthplace list covers major cities worldwide (with each country's time zone and longitude), and it automatically corrects for that country's daylight saving time and standard time changes at the time of birth. If your birthplace is not listed, choose the city in the same time zone with the nearest longitude.

Calculation Standards

What is a Manseryeok, and which kind is accurate?

As of 2026-10-24 · Edited by Sajunyang · about 3000 characters

One-line answer

A Manseryeok (萬歲曆) is the almanac that converts solar or lunar dates into the stem-and-branch pairs (the sexagenary cycle) for year, month, day and hour. An accurate Manseryeok calculates solar term times to the minute, accounts for Korea's standard time changes in 1908–1961 and the daylight saving periods of 1948–1960 and 1987–1988, and corrects for the solar time difference based on the birthplace's longitude (about −32 minutes for Seoul).

What does a Manseryeok calculate?

A Manseryeok finds four things. First, the Year Pillar: it sets the year's stem and branch based on the moment of Ipchun (Start of Spring). Second, the Month Pillar: it sets the month's branch based on the exact times of the 12 solar terms (Ipchun, Gyeongchip, Cheongmyeong, Ipha, Mangjong, Soseo, Ipchu, Baengno, Hallo, Ipdong, Daeseol, Sohan) and attaches the month's stem according to the year's stem. Third, the Day Pillar: since the sexagenary cycle advances one step per day, it counts the days from a reference date. Fourth, the Hour Pillar: it finds the two-hour branch containing the birth time and attaches the hour's stem according to the Day Master.

Printed almanacs often record solar terms only by date, so for someone born on the day of a solar term, the Month Pillar can be wrong depending on the time. Sajunyang calculates solar term times to the minute using astronomical computation.

Why does the same birthday give different charts on different sites?

The differences come from almost exactly four places: ① whether solar terms are read by date only or by exact time, ② whether daylight saving time and standard time changes are corrected, ③ whether solar time is corrected for the birthplace's longitude, and ④ whether the Day Pillar for someone born in the Ja hour (23:00–01:00) changes at 23:00 or at midnight. If all four are the same, any Manseryeok produces the same chart.

For example, for a birth in Seoul at 2:30 p.m. on July 15, 1988, correcting for daylight saving time gives 1:30 p.m. standard time, and local mean time makes it 12:58 p.m., which falls in the O hour (11:00–13:00) rather than the Mi hour (13:00–15:00). An entire Hour Pillar changes.

What are the calculation standards of Sajunyang's Manseryeok?

① Solar terms: times are calculated to the minute with an astronomical algorithm. ② Standard time: the history of changes to UTC+8:30 on April 1, 1908, UTC+9 on January 1, 1912, UTC+8:30 on March 21, 1954 and UTC+9 on August 10, 1961 is applied using IANA time zone data. ③ Daylight saving time: the periods in effect in 1948–1951, 1955–1960 and 1987–1988 are corrected automatically. ④ Local mean time: solar time is calculated from the birth city's longitude to set the Hour Pillar (about 32 minutes behind standard time for Seoul at 126.98°E). ⑤ Lunar calendar: the years 1910–2049 are converted using data based on the Korea Astronomy and Space Science Institute.

Just enter 'the clock time at the moment of birth'. Sajunyang does all the correcting. The Day Pillar change for the Ja hour defaults to 23:00 (the standard Rat hour), and the late Rat hour can be selected in advanced settings.

Four conditions that decide a Manseryeok's accuracy

Four conditions that decide a Manseryeok's accuracy
Condition	Error if skipped	Pillar affected
Solar term time (to the minute)	The month shifts by one for people born on a solar term day	Month Pillar
Daylight saving time · standard time changes	The time is off by one hour for those born in 1948–60 and 1987–88	Hour Pillar (and Day Pillar if near the Ja hour)
Birthplace local mean time	A difference of about 32 minutes for Seoul changes the hour branch	Hour Pillar
Ja hour handling	The date shifts by a day for those born between 23:00 and 24:00	Day Pillar · Hour Pillar

FAQ

Why does the starting age of the Luck Pillars differ between almanac apps?: The starting age is found by dividing the number of days from the birthday to the next (or previous) solar term by 3. It can differ by 1 depending on whether the solar term is read by date or by exact time, and whether the remainder is rounded.
How do I enter a birth outside Korea?: Enter the local clock time and the city of birth. Sajunyang's birthplace list covers major cities worldwide (with each country's time zone and longitude), and it automatically corrects for that country's daylight saving time and standard time changes at the time of birth. If your birthplace is not listed, choose the city in the same time zone with the nearest longitude.

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This article is reference material summarizing traditional Saju theory and does not replace medical, legal or investment judgment. Our calculation standards are published at About Sajunyang.