Lunar birthdays and family conventions

How to find your lunar birthday

A lunar birthday is the anniversary of your birth month and day in the Chinese calendar. The calendar is lunisolar: its months follow the Moon, while leap months keep the year in step with the seasons. Your lunar birthday will therefore usually fall on a different Gregorian date each year.

Keep your original Gregorian birth date together with its corresponding Chinese calendar year, lunar month and day, including whether the month was ordinary or leap. “Sixth month, day twelve” and “leap sixth month, day twelve” are different dates. If you have a family register or handwritten record, preserve its original wording too.

Find your upcoming lunar birthdays

Open the lunar birthday calculator, enter your ordinary civil date of birth, choose a starting Gregorian year, and select 1, 5 or 10 years of results. For each year, it shows the exact anniversary when one exists, matching your lunar month, day and ordinary- or leap-month status. When the required leap month or day thirty is absent, family-choice alternatives are clearly labelled—not presented as exact anniversaries.

Modern birth dates can be entered directly. For historical births, the tool uses Gregorian dates from October 15, 1582, and Julian dates through October 4, 1582; it does not accept October 5–14, 1582.

For an overseas birth recorded close to midnight, keep the local date, time and place together. A time-zone conversion can put the same birth on a different civil date, so record any converted date separately from the original entry.

Leap-month birthdays and a missing day thirty

A leap month takes the preceding month's number and adds a leap designation. An ordinary sixth month and a leap sixth month are therefore two different months within the same year. Each lunar month has 29 or 30 days, and the same numbered month need not have the same length every year.

Here is how the ordinary and leap sixth months differed in 2025, with the ordinary sixth month of 2026 for comparison. All dates in the table are Gregorian.

Someone born in the ordinary sixth month still has their birthday in the ordinary sixth month when a leap sixth month follows. Celebrating in the leap month as well would be an additional observance.

For a leap-month birthday, most years will not have an exact match. A family might celebrate in the ordinary month when the matching leap month is absent. Another approach is to celebrate in the ordinary month every year and mark the leap-month birthday separately when it returns. These are family choices, not rules imposed by the calendar. The leap-month table shows whether a particular year contains the matching leap month; leap-month birthdays do not follow a four-year cycle.

Day thirty poses a different problem: in some years, the same month ends on day twenty-nine. A family can use the month's last day—day twenty-nine—or the first day of the following month instead. Record that as a substitute celebration date, not a revised birth date.

Annual reminders

Click Download exact dates (.ics) and import the saved file into your calendar. It contains only exact Gregorian anniversary dates, each as a separate all-day event. Missing exact anniversaries and family-choice alternatives are excluded; add a chosen alternative manually.

The file covers only the selected years and does not create an annual recurrence. To add reminders for later years, return to the calculator and generate a file for that year range.

Record the birth date separately from the anniversary rule. A useful reminder includes the original lunar month and day, any leap-month designation, and the family's choice of date when the exact anniversary is unavailable.

Use the calculator’s 1-, 5- or 10-year lookup to plan reminders, keeping any family-choice celebration dates clearly labelled as substitutes. Downloaded exact anniversaries belong to their specific years. Do not set a saved civil date to repeat annually when tracking a lunar birthday, because its civil date can change from year to year.

You can hold the gathering on the anniversary or another convenient day without changing the birth record. The age on an invitation is a separate choice too: celebrating a lunar birthday does not require using nominal age.