How to use
- Gregorian → Lunar: pick a date to see its lunar month and day, the Chinese zodiac year, whether the month is long (30 days) or short (29 days), and which month is the leap month that year.
- Lunar → Gregorian: enter the lunar year (named after the Gregorian year of its Lunar New Year), then the month and day. In a year with a leap month, the month list includes it.
- Lunar birthday: enter your Gregorian or lunar birthday to get the date of your next lunar birthday, how many days are left, and the dates for the next 10 years.
How it works
The Chinese calendar is lunisolar:
- Months follow the moon. Each month starts on the day of the new moon and has 29 or 30 days. There is no fixed pattern; the months are worked out from the actual positions of the moon and sun.
- Years follow the sun. Twelve lunar months are about 11 days shorter than a solar year, so roughly every third year has a 13th (leap) month, giving it 383 to 385 days.
- Zodiac years change on Lunar New Year and repeat every 60 years.
The calculator looks dates up in the Hong Kong Observatory conversion tables for 1901 to 2100, calculated at UTC+8, rather than using an approximation. A few built-in calendar libraries are off by a day in some years (for example in 1954, 2027 and 2030); this calculator follows the Observatory.
Example
| Gregorian | Lunar |
|---|---|
| February 17, 2026 | Month 1, Day 1 — Lunar New Year, Year of the Horse |
| September 25, 2026 | Month 8, Day 15 — Mid-Autumn Festival |
| January 1, 2027 | Month 11, Day 24 of lunar year 2026 |
Lunar birthday for someone born on May 20, 1990 (Month 4, Day 26):
| Year | Gregorian date |
|---|---|
| 2026 | June 11 |
| 2027 | May 31 |
| 2028 | May 20 |
| 2029 | June 7 |
| 2030 | May 27 |