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Mutal Unnie Tools
Eight tools with just what you need for Saju calculations. No sign-up, no payment, and the date of birth you enter never leaves your browser.
Manseryeok calculator
Calculate the eight characters of your four Saju pillars from your birth date and time. Optionally correct for daylight saving time and former standard time; for births in the 11 p.m. hour, the two schools are shown side by side.
日Today's Iljin
Today's two characters, the lunar date, whether it's a Son-eomneun-nal and how many days until the next solar term. A two-week iljin table is included too.
月Lunar · Gregorian converter
Converts dates while distinguishing leap months and long and short months. Use it to move a lunar birthday to the Gregorian calendar. 1900–2050.
吉Son-eomneun-nal finder
Pick a period to see the Son-eomneun-nal within it. Narrow it down to days on weekends and public holidays, or leave out days that clash with your zodiac animal.
歲Age calculator
International, year-based and Korean counting age at once. Plus your weekday of birth, zodiac animal, the iljin of that day, days lived and your 10,000-day anniversary.
生Your lunar birthday, in Gregorian dates
Gregorian dates and weekdays for the next 15 years at once. Handles leap-month birthdays and birthdays on the 30th of a lunar month, too.
運Daeun calculator
Daeun starting age, forward or backward direction, and 10-year stem-branch cycles. It even shows the number of days to the solar term behind your starting age.
三Samjae checker
Choose a zodiac animal to see the years when Samjae comes and its entering, staying and leaving order. Instead of scaring you, it just tells you when.
Why we made these
Conversations about Saju often stall at “So what are my eight characters?” There are plenty of manseryeok sites, but some don't account for daylight saving time or former standard time, so for some people the results are simply wrong.
So we built the calculation on its own. What you get here is a calculation result, not a reading. Readings are in the Notes and the app.
How it's calculated
- Solar-term entry times in Korea Standard Time — we cross-checked all 48 of the 24 solar terms for 2027 and 2028 against public data from the Korea Astronomy and Space Science Institute (KASI): every date matched, and the minutes differed by 0–1 minute
- Lunar–Gregorian conversion — calculated from new moons in Korea Standard Time and the no-zhongqi leap-month rule, and round-trip verified across 55,002 days. Some dates differ from the Chinese lunar calendar, so we built it ourselves on the Korean standard
- Standard time & daylight saving time — reflects the actual transition history in the IANA time zone database as is
- Range — from 1900 to 2050
Why manseryeok results differ, and what we checked against, is explained in Why manseryeok apps give different results.
Privacy
The date of birth you enter in the tools is calculated only inside your browser. It isn't sent to a server and isn't stored. The Manseryeok calculator remembers your input on your device only, for convenience when you come back; this is erased when you clear your browser data.
Curious about what comes after the calculation?
To go on with the same engine to personality readings, today's rhythm and date selection, use the Mutal Unnie app. The Four Pillars chart table is completely free in the app, too.
Get the app for iPhone & AndroidFAQ
Are Mutal Unnie's tools free?
They're all 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 or stored.
Do they use the same calculations as the app?
They use the same standards. Solar-term entry times are calculated in Korea Standard Time, daylight saving time and the 1954–1961 UTC+8:30 standard time (127.5°E meridian) are corrected for, and lunar–Gregorian conversion uses round-trip-verified data. The app adds readings and event companion features on top of this.
What range of years can be calculated?
From 1900 to 2050. We prepared the solar-term times and lunar conversion data for this range.