Lunar–Gregorian converter
Convert between Gregorian and lunar dates, leap months included.
Convert between Gregorian and lunar dates, leap months included.
Method and limits
Traditional culture and self-reflection only — not scientific prediction, and not a basis for medical, financial, legal or major life decisions.
Privacy and use
No name, account or email required. Birth details remain in page memory and are removed on clear or reload. They are not stored or added to URLs. Only language preference is saved locally. The site is funded by ads: pages load Adsterra ads in an isolated frame, and Adsterra and its partners may receive your IP and browser information and use cookies for ad delivery and measurement (privacy policy: https://adsterra.com/privacy-policy/). The ad frame cannot read this page, and we never provide birth details or charts to advertisers. Pages also load an Adsterra popunder (clicking the page may open an ad tab in the background, frequency-capped per visitor) and a Social Bar (a corner overlay). These two scripts run on the page itself: we do not deliberately provide birth details or charts to advertisers, but we cannot prevent a third-party script from reading the page; use your browser's ad blocking if this concerns you. Each move to another page is a full page load. Visitors in the EEA, UK or Switzerland must agree before ads load. No analytics or external AI requests are enabled. You can refuse ads with your browser's ad or cookie blocking; the tools keep working.
About this tool
This tool converts both ways: enter a Gregorian date to get the lunar year, month and day, the year's stem-branch and zodiac; or enter a lunar date (tick the leap month if the year has one) to get the Gregorian date. The range is 1901–2099.
Conversion uses the open-source lunar-javascript library with the current lunar-calendar rules. To cast a BaZi or Zi Wei chart you do not need to convert; the chart pages accept a Gregorian birth date directly.
FAQ
How do I enter a leap month?
After choosing the lunar year and month, a “leap month” box appears when the year has one; tick it before converting.
Why is day 30 sometimes rejected?
Lunar months are 29 or 30 days; entering a non-existent day shows an error — use day 29.
Do I need to convert before casting BaZi?
No. The BaZi and Zi Wei pages take a Gregorian birth date.
Is my data uploaded?
No. Everything is calculated in your browser.