The rarest birthday is February 29.
This unique date occurs only once every four years, during a leap year. Consequently, the probability of being born on February 29 is significantly lower than any other day of the year.
Why is February 29 the Rarest Birthday?
February 29, often referred to as a "leap day," is added to the calendar in a leap year to keep our Gregorian calendar aligned with the Earth's orbit around the sun. Without leap days, the calendar would drift over time, causing seasons to occur at different times of the year.
Being born on this date means you have approximately a 1 in 1,460 chance of having this birthday. This contrasts sharply with the roughly 1 in 365 or 1 in 366 chance for any other day, making February 29 an exceptionally uncommon birth date.
People born on February 29 are known as "leaplings" or "leapers." While their official birth date only appears every four years, they typically celebrate their birthday on February 28 or March 1 in non-leap years.
