Lunar Birthday to Gregorian: the Date Each Year
Many older Chinese and Taiwanese people still celebrate their lunar birthday, which lands on a different Gregorian date every year and usually means a trip to the almanac. Enter a lunar birthday once and the converter lists its Gregorian date for the next 10 years.
Lunar ⇄ Gregorian converter
Pick a direction and enter a date. For lunar to Gregorian, tick "leap month" if the date is in a leap month; a lunar birthday also shows its Gregorian date for the next 10 years. Everything is calculated in your browser.
For lunar dates, month 1 is the first month and month 12 the last (the "La" month). Covers the years 1901 to 2099.
Why the date changes every year
Lunar months follow the moon. A lunar year runs about 354 days, some 11 days shorter than a Gregorian one, and a leap year adds about 30 days more. So the same lunar birthday moves about 11 days earlier each year, then jumps back every two or three years, staying within roughly a one-month window.
Two birthdays that need adjusting
| Situation | Common custom | Example |
|---|---|---|
| Born in a leap month, in a year with no such leap month | Keep it in the regular month of the same name | Leap 6th month, day 10 → 6th month, day 10 |
| Born on day 30, in a year when that month has only 29 days | Keep it on the last day of the month (day 29) | 4th month, day 30 → 4th month, day 29 |
The converter applies both rules automatically and notes in the table which years were adjusted.
Which date does BaZi use?
BaZi uses your Gregorian birth date and time. Its year changes at the Start of Spring and its months at the solar terms, which do not line up with lunar months. If you only know your lunar birthday, convert it to the Gregorian date of your birth year above, then enter that in the BaZi chart.
Common misconceptions
A lunar birthday lands on about the same Gregorian day every year.
It moves within about a month, and jumps most in leap years.
The birthday on a Taiwanese ID card is a lunar date.
Taiwanese ID cards use the Gregorian calendar (in Minguo years).
A straight word: BaZi follows the solar terms, not lunar dates
The Chinese calendar is lunisolar: months follow the moon, and festivals and lunar birthdays are counted by it. BaZi does not use lunar months, though. Its year changes at the Start of Spring and its months at the solar terms, and a chart is cast from the Gregorian birth date and time. Our conversions use China Standard Time (UTC+8), the same time zone as the lunar calendar published by Taiwan's Central Weather Administration. Everything on this site is for reference and entertainment.
Now cast your BaZi chart
Use your Gregorian birth time to get your year, month, day and hour pillars, your Day Master, Five Elements and Ten Gods.
Lunar birthdays: common questions
How do I convert a lunar birthday to a Gregorian date?
Choose "Lunar → Gregorian" in the converter on this page and enter your lunar birthday. It lists that year's date and the next 10 years.
How is a leap-month birthday kept in a year without that leap month?
By custom, in the regular month of the same name.
I was born on day 30. What happens when the month has only 29 days?
Most people celebrate on day 29 in those years.