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Manseryeok calculator
Enter your birth date and time to get the eight characters of your four Saju pillars. The default is the same as the app: standard time, with the late Ja hour counted as the same day. You can optionally correct for daylight saving time and former standard time. No sign-up, no payment.
Date and time of birth
If you only know your lunar birthday, first convert it to Gregorian with the Lunar–Gregorian converter.
Only affects births between 11:00 and 11:59 p.m. If that applies, both results are shown together. What's the difference?
To read into your Eight Characters
To go on with the same calculation engine to your personality, rhythms and today's fortune, use the Mutal Unnie app. The Four Pillars chart table is completely free in the app, too.
Download on the App StoreWhat this calculator does
It converts your birth time to the standard used in Saju, then assembles your four pillars from the solar terms and the sixty Gapja. All calculations happen inside your browser, and the date of birth you enter is never sent to a server.
Optional corrections
- Daylight saving time −60 minutes — if your birth falls within the periods it was in effect in 1948–1951, 1955–1960 or 1987–1988. See the periods by year
- 127.5°E → 135°E, +30 minutes — if you were born between March 21, 1954 and August 9, 1961. The story of Korea's standard time changes
You can use the same default standard as the app, or turn on the historical corrections and compare the results. What was applied is shown above the results.
Left up to you
- Ja-hour schools — which day to assign the day pillar to for births in the 11 p.m. hour. Late and early Ja hour
- True solar time — whether to align clock time with the actual sun. Adds the equation of time to a longitude correction.
These two are matters of interpretation rather than fact, so we don't pick a right answer for you. Toggle them on and off and see how the results change.
Data and verification
Solar-term entry times are in Korea Standard Time, and we compared all 48 of the 24 solar terms for 2027 and 2028 with public calendar data from the Korea Astronomy and Space Science Institute. All dates matched, and the minute values differed by 0–1 minute (checked 2026.10.03). The lunar–Gregorian conversion was round-trip verified across 55,002 days from 1900 to 2050 with no mismatches. The calculation range is 1900–2050. Details are in Why manseryeok apps give different results.
What this calculator doesn't do
What you get here is a calculation result, not a reading. For what your Eight Characters mean, start with How to read Saju: a complete guide; explanations for each day pillar are collected in The 60 Gapja day pillars.
FAQ
Is the Manseryeok calculator free?
It's free, and no sign-up is needed. The date of birth you enter is calculated only inside your browser and is never sent to a server.
What if I don't know my birth time?
If you choose “I don't know my birth time,” it calculates a Three Pillars reading (三柱) without the hour pillar — the six characters of the year, month and day pillars. Leaving out an unknown time is more accurate than entering one at random.
Does it use the same calculation standards as the app?
The default is the same as the app: standard time, with the late Ja hour counted as the same day. Corrections for daylight saving time and former standard time are optional. With those corrections on, 60 minutes are subtracted during daylight saving periods (summers of 1948–1951, 1955–1960 and 1987–1988), and 30 minutes are added during the period of UTC+8:30 standard time on the 127.5°E meridian (March 21, 1954 – August 9, 1961). The results screen shows what was corrected. True solar time correction varies by school, so it's left as an option.
What range of years can be calculated?
From 1900 to 2050. We prepared the solar-term times and lunar conversion data for this range. Solar-term entry times are in Korea Standard Time and were cross-checked against public astronomical data.