Chinese Lunar Calendar Converter (Gregorian Date to Chinese Lunar Date)
Convert any date from 1901 to 2099 to the Chinese lunar calendar: lunar month and day in Chinese, leap months, the sexagenary year, zodiac animal and element, and the start of every lunar month.
How it works
Months begin on the day (Beijing time, UTC+8) of each astronomical new moon · month 11 contains the December solstice · in a year with 13 new moons between two month-11s, the first month without a principal solar term (zhongqi, a 30° step of the Sun's longitude) is a leap month · year = 1st month; sexagenary year = (lunar year − 4) mod 60 · new moons: Meeus ch. 49; Sun: Meeus ch. 25
The Chinese calendar is lunisolar: each month starts on the day of a new moon, and a leap month is inserted about every three years so the year stays in step with the seasons. Since 2017 the rules are set by the Chinese national standard GB/T 33661-2017, which uses the true astronomical new moon and solar terms in Beijing time. The calculator implements those rules (following Reingold & Dershowitz) and gives the lunar month and day, written in Chinese as on calendars (for example 八月十五 for the Mid-Autumn Festival), plus the year's stem-branch name, animal and element. Lunar birthdays, festivals and the Chinese gender chart all use this date.
Worked example
Thursday, October 8, 2026: the last new moon before it, in Beijing time, fell on Friday, September 11, 2026, the first day of the eighth lunar month, so October 8 is the 28th day — 八月廿八 (month 8, day 28). It belongs to the lunar year 丙午 (Bing Wu), the year of the Yang Fire Horse, which began on Tuesday, February 17, 2026 and ends before the next Chinese New Year on Saturday, February 6, 2027. This eighth month has 29 days, and the Mid-Autumn Festival (八月十五) fell on September 25, 2026.
Sources: Reingold & Dershowitz, Calendrical Calculations, ch. 19 — The Chinese Calendar · Hong Kong Observatory — Gregorian–Lunar Calendar Conversion Table
Frequently asked questions
How do I find my Chinese lunar birthday?
Enter your Gregorian birth date. The result is your lunar month and day; your lunar birthday in a later year is that same lunar month and day, which falls on a different Gregorian date each year.
What is a leap month in the Chinese calendar?
Twelve lunar months are about 11 days shorter than a solar year, so roughly every 2–3 years a 13th month is added. It repeats the number of the previous month and is marked 闰 (rùn); 2025 had a leap sixth month and 2028 has a leap fifth month.
Why can the lunar date differ from other calendars by a day?
The month starts on the day of the new moon in China's time zone (UTC+8). Calendars computed for Vietnam (UTC+7) or Korea (UTC+9), or older tables using mean moons, can occasionally place a new moon on a different day.
When does the Chinese zodiac year change?
Traditionally at Chinese New Year, the first day of the first lunar month (between January 21 and February 20). Some astrology systems such as BaZi use Lichun, about February 4, instead.
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This calculator is for educational purposes. Double-check important results before acting on them.