Julian Date Converter
Vietnamese lunar conversion
Vietnamese Lunar Date Converter
Convert Gregorian dates into Vietnamese lunar dates using a Vietnam UTC+7 lunisolar calculation, or convert explicit Vietnamese lunar input back into Gregorian dates.
Live output
Result
Choose a direction, enter a Gregorian date or explicit Vietnamese lunar input, and the result appears here without leaving the page.
Guide
Convert dates with the Vietnamese Lunar Date Converter
The Vietnamese Lunar Date Converter changes Gregorian dates into Vietnamese lunar dates and converts explicit Vietnamese lunar 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 a Vietnam UTC+7 East Asian lunisolar calculation. Reverse input uses LUNAR_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 is a calculated modern Vietnamese lunar conversion. It is not a historical almanac table and should not be treated as a festival calculator.
What it handles
Vietnamese lunar calendar conversion coverage
The converter supports both Gregorian to Vietnamese and Vietnamese 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 Vietnamese
Enter a Gregorian date and return the matching Vietnamese lunar calendar date with leap-month state and weekday.
Vietnamese to Gregorian
Enter LUNAR_YEAR-MONTH-DAY with optional -L for leap months for a Vietnamese lunar 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 Vietnamese lunar 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 Vietnamese
Use this direction for Gregorian input such as 2026-06-30. The verified example returns 2026-06-30 -> 2026-05-16.
Choose Vietnamese to Gregorian
Use this direction for explicit input such as 2026-05-16. Add the documented leap-month suffix only when the source date requires it.
Check the calendar basis
Use this page for Vietnam UTC+7 calculations. Do not assume the Chinese lunar converter will always produce the same result for dates near month boundaries.
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 Vietnamese lunar calendar date
2026-06-30 -> 2026-05-16The Gregorian date 2026-06-30 converts to Vietnamese lunar calendar 2026-05-16.
Vietnamese lunar calendar date to Gregorian date
2026-05-16 -> 2026-06-30The input 2026-05-16 converts back to Gregorian 2026-06-30.
FAQ
Vietnamese lunar 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 is a calculated modern Vietnamese lunar conversion. It is not a historical almanac table and should not be treated as a festival calculator.
Reference
Calendar implementation reference
This converter is documented against its implementation basis: a Vietnam UTC+7 East Asian lunisolar calculation. The reference link points to ICU calendar services when the page uses an ICU calendar identifier.