Lunar Calendar Converter (Korea, China, Vietnam)
Convert dates between the Gregorian calendar and the Korean, Chinese and Vietnamese lunar calendars, which fall on different days in some months, with leap months and the zodiac year.
Gregorian → lunar
Lunar → Gregorian
How the three calendars are worked out
- A lunar month starts on the day of the new moon, and the month that contains the winter solstice is month 11. Because the day of the new moon depends on the time zone, a new moon shortly before midnight in China can fall after midnight in Korea, and the month then starts a day later there.
- Korean dates follow the Korea Astronomy and Space Science Institute (KASI), Chinese dates the Hong Kong Observatory tables (China Standard Time). Vietnamese dates are calculated for UTC+7 from 1968; before that they are the Chinese dates.
- A year with 13 months has a leap month, which repeats the number of the month before it. The three calendars can put the leap month in different years, as in 1984 and 1985.
- The year's sexagenary name and zodiac animal change at the lunar new year. Saju and other fortune-telling often start the year at 立春 (around 4 February) instead. Vietnam has the cat and the buffalo where China and Korea have the rabbit and the ox.
- Everything runs in your browser. The dates you enter are not sent to LeedyBox or saved.
Source: 한국천문연구원 천문우주지식정보: 음양력 변환 · Last checked:
Source: 香港天文台: 公曆與農曆日期對照表 · Last checked:
Source: Cổng TTĐT Chính phủ: Lịch nghỉ Tết Nguyên đán Ất Tỵ 2025 · Last checked:
Wrong result? If a date converts wrongly, email us the date, the calendar you chose and the result you expected (with its source if you have one), so we can check it.
Does a sentence on this page sound unnatural in your language? Let us know that too.
How to use
- Choose the calendar: Korea, China or Vietnam. The page language picks one first, and the three can differ by a day or, rarely, by a month.
- To find the lunar date of a day, pick it under "Gregorian → lunar". The result shows the lunar date, the year's sexagenary name and animal, the length of the month, the leap month of the year and the same day in the other two calendars.
- To convert a lunar date, enter the lunar year, month and day, and tick "Leap month" for a date in a leap month. The note under the inputs says which month is leap in that year.
- For a lunar birthday, convert it for this year or next year; it falls on a different Gregorian day every year.
Frequently asked questions
Why do the Korean and Chinese lunar dates sometimes differ?
Both calendars start a month on the day of the new moon, but Korea uses UTC+9 and China UTC+8. When the new moon comes between midnight and 1 a.m. Korean time, it is still the previous day in China, so the Chinese month starts a day earlier. The Chinese New Year of 2027 is on 6 February, the Korean Seollal on 7 February.
When is Vietnamese Tết different from the Chinese New Year?
Vietnam calculates its lunar calendar for UTC+7. In some years that moves the new moon to the day before: Tết was on 29 January 1968 and 17 February 2007, a day before the Chinese New Year. In 1985 the leap month fell differently, and Tết came on 21 January, a month before the Chinese New Year of 20 February.
What is a leap month?
Twelve lunar months are about 11 days shorter than a solar year, so about every three years a thirteenth month is added. It takes the number of the month before it: in Korea, 2025 had a leap month 6 after month 6.
Which years can be converted?
From the lunar new year of 1901 (19 February 1901) to 31 December 2050, the range covered by both the Korean (KASI) and Chinese (Hong Kong Observatory) tables.
Why does Vietnam have the year of the cat?
The Vietnamese zodiac uses the cat (Mèo) for the fourth earthly branch, where China and Korea use the rabbit, and the buffalo (Trâu) instead of the ox. The years are the same; only the animal differs.
Is the date I enter sent anywhere?
No. The month tables are part of the page, the conversion runs in your browser, and nothing you enter is saved.