when is your birthday if born on leap year
February 29 A person born on February 29 may be called a "leapling", a "leaper", or a "leap-year baby".[6] In non-leap years, some leaplings celebrate their birthday on either February 28 or March 1, while others only observe birthdays on the authentic intercalary date, February 29.
February 29 Thus, in England and Wales or in Hong Kong, a person born on February 29 will have legally reached 18 years old on March 1. If they were born in Taiwan they legally become 18 on February 28, a day earlier. In the United States, according to John Reitz, a professor of law at the University of Iowa, there is no "... statute or general rule that has anything to do with leap day."[12] Reitz speculates that "March 1 would likely be considered the legal birthday in non-leap years of someone born on leap day,"[12] using the same reasoning as described for the United Kingdom and Hong Kong.
February 29 A leap day is observed because a complete revolution around the Sun takes approximately 6 hours longer than 365 days (8,760 hours). A leap day compensates for this lag, realigning the calendar with the Earth's position in the Solar System; otherwise, seasons would occur earlier than intended in the calendar year. The Julian calendar used in Christendom until the 16th century added a leap day every four years; but this rule adds too many days (roughly 3 every 400 years), making the equinoxes and solstices shift gradually to earlier dates. By the 16th century the vernal equinox had drifted to March 11, and the Gregorian calendar was introduced both to shift it back by omitting several days, and to reduce the number of leap years via the "century rule" to keep the equinoxes more or less fixed and the date of Easter consistently close to the vernal equinox.[1][2]
Leap year In the Gregorian calendar, the standard calendar in most of the world, most years that are multiples of 4 are leap years. In each leap year, the month of February has 29 days instead of 28. Adding one extra day in the calendar every four years compensates for the fact that a period of 365 days is shorter than a tropical year by almost 6 hours.[4] Some exceptions to this basic rule are required since the duration of a tropical year is slightly less than 365.25 days. The Gregorian reform modified the Julian calendar's scheme of leap years as follows: