Julian Date Converter
Korean lunisolar conversion
Korean Traditional Date Converter
Convert Gregorian dates into Korean traditional lunisolar dates with ICU Dangi support, or convert explicit Dangi inputs back into Gregorian dates.
Live output
Result
Choose a direction, enter a Gregorian date or explicit Korean traditional input, and the result appears here without leaving the page.
Guide
Convert dates with the Korean Traditional Date Converter
The Korean Traditional Date Converter changes Gregorian dates into Korean traditional dates and converts explicit Korean traditional input back into Gregorian dates. It is designed for deterministic date lookup where leap months and regional calendar basis need to be visible.
The page uses ICU Dangi calendar fields. Reverse input uses ICU Dangi EXTENDED_YEAR-MONTH-DAY with optional -L for leap months so the converter can validate the exact year, month, day, and leap-month state instead of guessing from a festival name or cyclic year label.
This converter exposes ICU Dangi behavior. It is not a hand-curated historical Korean almanac and does not calculate holidays or observance rules.
What it handles
Korean traditional Dangi calendar conversion coverage
The converter supports both Gregorian to Korean and Korean to Gregorian. Both directions use the same calendar basis, which makes the examples and reverse validation consistent.
Leap months are represented explicitly. If a leap-month marker is supplied for a date that the implementation does not produce, the converter rejects the input rather than silently changing the date.
Gregorian to Korean
Enter a Gregorian date and return the matching Korean traditional Dangi calendar date with leap-month state and weekday.
Korean to Gregorian
Enter ICU Dangi EXTENDED_YEAR-MONTH-DAY with optional -L for leap months for a Korean traditional Dangi calendar date and convert it back into Gregorian form.
Round-trip validation
The reverse direction checks that the converted date returns to the same calendar fields, including leap-month markers.
How to use
Use the Korean traditional Dangi calendar conversion modes
Choose the mode that matches the source date you already have. The Gregorian direction accepts a standard date field; the reverse direction expects the explicit numeric calendar syntax shown in the form help.
Do not omit leap-month suffixes when the source date is in a leap month. Without the suffix, the converter treats the input as the regular month of the same number.
Choose Gregorian to Korean
Use this direction for Gregorian input such as 2026-06-30. The verified example returns 2026-06-30 -> 4359-05-16.
Choose Korean to Gregorian
Use this direction for explicit input such as 4359-05-16. Add the documented leap-month suffix only when the source date requires it.
Check the calendar basis
Use this page for ICU Dangi conversion. It is not just a renamed Chinese lunar converter, and the extended-year value belongs to ICU Dangi input.
Examples
Reference conversions from the local implementation
These examples are generated from the same local conversion functions used by the form. They show the exact reverse-input notation accepted by this page and the Gregorian date returned when the value is converted back.
Gregorian date to Korean traditional Dangi calendar date
2026-06-30 -> 4359-05-16The Gregorian date 2026-06-30 converts to Korean traditional Dangi calendar 4359-05-16.
Korean traditional Dangi calendar date to Gregorian date
4359-05-16 -> 2026-06-30The input 4359-05-16 converts back to Gregorian 2026-06-30.
FAQ
Korean traditional Dangi calendar conversion notes
Traditional lunisolar calendars can look similar while using different time zones, calendar identifiers, or historical assumptions. These answers define what this page actually converts.
Can I enter a festival name or animal year?
No. Reverse conversion requires numeric year, month, and day fields because named years and festivals are not unique enough for deterministic conversion.
How are leap months handled?
Use the documented leap suffix only when the source date is in a leap month. The converter validates that the leap marker is possible for the entered date.
Does this replace a historical almanac?
This converter exposes ICU Dangi behavior. It is not a hand-curated historical Korean almanac and does not calculate holidays or observance rules.
Reference
Calendar implementation reference
This converter is documented against its implementation basis: ICU Dangi calendar fields. The reference link points to ICU calendar services when the page uses an ICU calendar identifier.