BAZI KNOWLEDGE BASE
Born on 29 February: should a BaZi birthday be changed?
If you were born on 29 February, retain 29 February in the actual birth year. It need not become 28 February or 1 March. A leap day is an ordinary chronological day and the Day Pillar (the two-symbol column for the birth day) advances normally. Its rarity does not itself add an element, Ten God (one of ten traditional relationship labels defined relative to the birth-day element) or special chart category.
Not every fourth year has 29 February
In the Gregorian calendar, divisibility by four normally makes a leap year. A century year divisible by 100 must also be divisible by 400. Thus 1900 had no 29 February, while 2000 and 2024 did. Check the full year, not just its last two digits.
The day cycle continues through 28 February, 29 February and 1 March
If 28 February of a leap year has cycle index n, 29 February has n+1 and 1 March n+2, wrapping after 59. Neither repeat the previous Day Pillar nor omit 29 February. This is a counting illustration, not an unverified stem-branch assignment to a real date.
Year and Month Pillars still follow their own term boundaries. An extra Gregorian day is not an extra lunar month and does not create a thirteenth BaZi month. Leap days and leap months are different calendar questions.
A birthday celebration in a common year does not reset the natal chart
A family may choose its own celebration date in a common year, but the original birth event remains fixed. Entering this year’s 28 February as the birth date would create different input. Keep the natal chart (the chart calculated for the birth moment) separate from the year being discussed in a timing reading.
If input fails, check the year and calendar first
Confirm that the record actually means Gregorian 29 February and that the year was transcribed correctly. Lunar month two, day twenty-nine needs a complete lunar-date conversion; it has no fixed relationship to Gregorian 29 February. Do not move the date merely to make a form accept it.