Manseryeok
Manseryeok: a complete guide
— five points where results diverge
If the same birth date gives different Eight Characters in different apps, the places where they diverge are fixed. Here's how to judge which side is right.
Manseryeok results diverge in five places — the Ipchun cutoff · solar-term times · the Ja-hour boundary · daylight saving time · true solar time. A birth date that isn't caught by any of these five gives the same characters in any manseryeok. The first three have a right and a wrong answer once verified; the last two split by school, so there isn't just one correct answer.
Where are the five points where results diverge?
These are the five. Check first whether your birth date is caught by any of them, and you'll find the cause quickly.
| Where it diverges | Who's affected | Is there a right answer? |
|---|---|---|
| Ipchun cutoff | Born January to early February | Yes — Saju uses Ipchun |
| Solar-term times | Born on the day of a solar term | Yes — astronomical calculation to the minute |
| Ja-hour boundary | Born 11 p.m.–midnight | No — the late vs. early Ja-hour schools |
| Daylight saving time | Born in summer in a year when it was in effect | Yes — records of when it was actually in effect |
| True solar time | Everyone, depending on whether it's applied | No — correcting vs. non-correcting schools |
How do I judge which side is right?
First, separate the points that have a right answer from those that don't. Where it's astronomical calculation, like solar-term times, comparing with public data settles it. The Ja-hour boundary and true solar time, on the other hand, are differences of perspective, so the best you can do is look at both results and know which standard each one uses.
Here are the verification results for the Mutal Unnie Saju engine: the iljin and year stem-branch matched in every random sample checked against the public lunar–Gregorian data of the Korea Astronomy and Space Science Institute (KASI); solar-term entry times for all 48 of the 24 solar terms in 2027 and 2028 matched KASI's public data by date (with a 0–1 minute difference in the minutes shown); and lunar–Gregorian conversion showed no mismatches in a 55,002-day round-trip check from 1900–2050. Where the correct answer splits, we state the default and show both results together.
Does it matter which country's standard the lunar calendar is calculated by?
It does. Between a lunar calendar calculated in Korea Standard Time and one that uses China's nongli as-is, there are 427 days between 1900 and 2050 on which the Son-eomneun-nal verdict differs. Even Seollal 2027 is February 7 by the Korean lunar calendar but February 6 by the Chinese nongli.
Why they differFive causes
Why manseryeok apps give different results — five fault lines and what we found when we checked
All five points in one place, plus the criteria for judging which side is right.
BasicsThe Saju new year begins at Ipchun
Why people born in January get confused about their zodiac animal. Ipchun 2027 is February 4 at 10:46.
BoundaryBorn at 11 p.m.? — the late and early Ja hour
Same moment, different date. How the two schools differ.
BoundaryTwelve years of daylight saving time — people whose hour pillar shifts by one
If you were born in the summer of a year when it was in effect, the clock time and the actual time are an hour apart.
BoundaryThe three changes to Korea Standard Time — including true solar time
There were periods when the standard time itself changed. Plus the debate over true solar time correction.
When you don't know your timeReading the Three Pillars
Accuracy when you don't know your birth time
Of the Eight Characters, your birth time sets only two. The other six come out unchanged.
BasicsHow to find your birth time — where the records are
From birth certificates and hospital records to the family relationship register — the paths you can actually follow.
BasicsFinding your lunar birthday on the Gregorian calendar — leap months and the conversion steps
Down to handling leap months and the lunar 30th. Get the conversion steps wrong and you'll be a day off.
Check it yourselfNo sign-up, right in your browser
Manseryeok calculator — your Eight Characters, with both schools compared
Daylight saving and the former standard time are optional corrections. Shows the results of both Ja-hour schools side by side.
ToolsLunar · Gregorian converter
Distinguishes leap months and long/short months. Covers 1900–2050.
ToolsDaeun calculator — including how your Daeun starting age is derived
Shows the exact number of days to the solar term. It's also why apps can differ by a year in age.
HubThe 24 solar terms: a complete guide — jeol vs. gi
The 12 jeol actually used in Saju, and their 2027 and 2028 entry times.
FAQ
Why do different manseryeok give different results for the same birth date?
Results diverge at five points — the Ipchun cutoff · solar-term times · the Ja-hour boundary · daylight saving time · true solar time. A birth date that isn't caught by any of these gives the same characters in any manseryeok.
Is there only one correct answer in manseryeok calculations?
Half the time. Solar-term entry times and lunar–Gregorian conversion are astronomical calculations, so there's one correct answer, but the Ja-hour boundary and true solar time are differences between schools, so there isn't just one. For those points, it's safest to state the default and look at both results.
Can I get a Saju reading without knowing my birth time?
Yes. Your birth time only determines two of the Eight Characters. Reading with the remaining six is called a Three Pillars reading (samju). Entering a guessed time actually makes the result shakier, so we don't recommend it.
How can I check whether a manseryeok calculation is correct?
Compare it with public data: the iljin and year stem-branch against KASI's lunar–Gregorian data, and solar-term entry times against public astronomical data, to the minute. Mutal Unnie has confirmed that all 48 dates of the 24 solar terms match and completed a 55,002-day round-trip check of lunar–Gregorian conversion.
Check your Eight Characters first
The Four Pillars chart table is fully free in the app too — even on paid reading screens.
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