Chinese Lunar Calendar Converter — Solar ⇄ Lunar Date
This tool converts between the Gregorian solar calendar and the traditional Chinese lunar calendar in both directions, including leap months, using the same calendar library as the year pages below.
Supported range: 1900–2100.
Solar date → Lunar date
Please enter a valid date in the supported range.
- Lunar date
- Year (GanZhi)
- Zodiac sign
Lunar date → Solar date
Please enter a valid date in the supported range.
- Solar date
How do leap months work in the Chinese lunar calendar?
The lunar calendar adds an extra ('leap') month roughly every three years to keep lunar years aligned with the solar year. A leap month repeats the number of the month before it (for example, a leap fourth month follows the fourth month) and is marked separately when converting dates.
Why does the same solar date fall on a different lunar date every year?
The lunar calendar's months follow the moon's phases (about 29.5 days each), while the solar calendar follows the sun. Because 12 lunar months are about 11 days shorter than a solar year, the same solar date drifts to a different lunar date each year until a leap month resets the alignment.
What calendar library computes these conversions?
All conversions on this page are computed by lunar-typescript, an open-source implementation of traditional Chinese calendar algorithms — see the About page for details.
Solar terms follow astronomical calculation; the lunar calendar and leap-month placement follow the traditional Chinese calendar rules encoded in lunar-typescript · Last updated 2026-09-11