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How to handle a lunar birthday in a leap month

A Chinese leap month (闰月) is an extra month after a regular month in some years. Someone born on 闰六月初一 has that date in 2025 and does not have a leap sixth month in 2026.

For a saved yearly 日子, ClaimBell can:

  • use the regular month of the same number in years without that leap month, or
  • skip those years.

The default is the regular month. That is a household scheduling choice. It is not a single cultural rule, and this page does not pick a “correct” celebration date.

The examples use a fictional person, Aunt Mei, born 闰六月初一.

Ordinary sixth month, then leap sixth month

In 2025 the regular sixth month comes first, then the extra leap sixth month, then the seventh month. Mei’s birthday is the first day of the leap month, not the first day of the regular sixth month.

BandFirst dayThroughMei
六月 (regular)25 June 202524 July 2025no
闰六月 (leap)25 July 2025 — 初一22 August 2025yes
七月23 August 2025—no

Fictional example · 2025

六月 (regular)六月25 June 2025through 24 July 2025 · Mei no
闰六月 (leap) · Mei yes闰六月25 July 2025 — 初一through 22 August 2025
七月七月23 August 2025—
Three dated bands from the table above. Mei is on 闰六月初一, not 六月初一.

Official tables: 2025 English, 2025 Chinese (閏六月 on 25 July). Saving 六月初一 would remind the family on 25 June 2025, a month before Mei’s leap-month date.

The next year with a leap lunar month in this stretch is 2028 (闰五月). 2026 and 2027 have no leap lunar month.

Fallback or skip in 2025–2028

Fallback (default): in a year without 闰六月, use 六月初一.

YearLeap sixth month?Date usedGregorianOfficial table
2025Yes闰六月初一25 July 20252025
2026No六月初一14 July 20262026
2027No六月初一4 July 20272027
2028No六月初一22 July 20282028

Skip: keep the leap-month date. Years without that leap month have no occurrence:

YearOccurrence
202525 July 2025
2026none
2027none
2028none

Skip means no scheduled occurrence of that reminder that year. It does not move the date to a neighbouring day. A 29-day leap month also has no 三十; that is a missing day, not a reason to use the regular month.

The website and the app

On the lunar converter you look up one year. If the leap month is missing that year, the converter uses the regular month and labels that clearly. It does not offer skip.

In the app, a yearly 日子 on a leap month shows Leap month. Fallback to the regular month, with If this leap month does not occur in a recurrence year. Turn the switch off to skip those years. The app previews later Gregorian dates before you save.

A person profile can mark Leap month on a birthday without that switch. Fallback versus skip belongs to the 日子 reminder.

This public page does not save the lookup. Save birthday on the converter opens the app; you still enter the date there. App export is Family JSON. There is no ICS file.

A family choice

Use fallback if you want a date every year, usually in the regular month, close to the original season.

Use skip if the leap month is the point, and a year without that extra month should not invent a substitute.

Tell the people who need to show up which Gregorian day you are using this year. The converter is for that conversation. It does not announce a family tradition.

Convert any lunar birthday for a chosen year. 八月十五 in 2026 is Friday, 25 September 2026 on the 2026 Observatory table.