Feb. 29 aka Leap Day is coming. How old is a leap year baby in 2024? We did the math for you (2024)

When is Leap Year and Leap Day? It's Thursday, Feb. 29, 2024.

Happy birthday, leaplings! As you know, this February is special: 2024 is a Leap Year.

We know you know how old you are. We can calculate our age in dog years, so why not Leap Day years?

Unlike the canine formula — anyone can multiply their age by 7 to get the answer — the Leap Day math applies to people born on Feb. 29.

Those born on that day don't always get to celebrate their actual birthday — since that date occurs only every four years. But not to worry, someone born on Leap Day still gets to celebrate a birthday (see below).

When is Leap Day 2024?

Leap Day is Thursday, Feb. 29, 2024.

Why does Leap Day occur once every four years?

Our calendar is not entirely in sync with our planet's trip around the sun.

A common year has 365 days on the calendar while a leap year boasts that extra day. Their purpose keeps our calendar in sync with the seasons and solar year, or the length of time it takes the earth to complete its orbit around the sun, which is about 365¼ days, according to timeanddate.com.

Every four years, we have 366 days on the calendar. If we didn't observe leap years, our seasons would be messed up as our equinoxes and summer and winter solstice would no longer align with the seasons.

"If there were no leap years, the seasons would completely swap every 750 years, i.e. the middle of summer would become the middle of winter − calendar climate change," astronomy expert Dr. Stephen Hughes of Queensland University of Technology said in a Feb. 29, 2012 (aLeap Year) article on AsianScientist.com.

If your birthday is on Feb. 29, which day do you use to celebrate? What date do you use for official documents or ID?

Those born on that day don't always get to celebrate their actual birthday — since that date occurs only every four years. Someone born on Leap Day typically celebrates birthdays on Feb. 28 or March 1. But Feb. 29 is still used for identification and important documents.

Happy birthday! How old would you be if you were born on Leap Day?

How old are you technically if you were born on Leap Day? If you were born on Leap Day 1924, you would be 100 years old, or 25 in Leap Day years.

The year must be evenly divisible by 4. If the year can be evenly divided by 100, it is not a leap year unless the year is also evenly divisible by 400, according to mathisfun.com. For example, 2000 and 2400 are leap years, but 1800, 1900, 2100, 2200, 2300 and 2500 are not.

We've done the math for you in our age guide − it shows your age in "human" years and Leap Day years. If you were born on Feb. 29 …

1904: You'd be 120 years old in human years or 30.

1908: You'd be 116 years old in human years or 29.

1912: You'd be 112 years old or 28.

1916: You'd be 108 years old or 27.

1920: You'd be 104 years old or 26.

1924: You'd be 100 years old (Congrats, you're a centenarian!) or 25.

1928: You'd be 96 years old or 24.

1932: You'd be 92 years old or 23.

1936: You'd be 88 years old or 22.

1940: You'd be 84 years old or 21 (the legal age to drink alcoholic beverages in the U.S).

1944: You'd be 80 years old or 20.

1948: You'd be 76 years old or 19.

1952: You'd be 72 years old or 18 (the legal age to vote in the U.S. or buy lottery tickets).

1956: You'd be 68 years old or 17.

1960: You'd be 64 years old or 16 (the legal age to drive in the U.S.).

1964: You'd be 60 years old or 15 (the legal age to get a learner's permit to drive in the U.S.).

1968: You'd be 56 years old or 14.

1972: You'd be 52 years old or 13.

1976: You'd be 48 years old or 12.

1980: You'd be 44 years old or 11.

1984: You'd be 40 years old or 10.

1988: You'd be 36 years old or 9.

1992: You'd be 32 years old or 8.

1996: You'd be 28 years old or 7.

2000: You'd be 24 years old or 6.

2004: You'd be 20 years old or 5.

2008: You'd be 16 years old (the legal age to drive in the U.S.) or 4.

2012: You'd be 12 years old or 3.

2016: You'd be 8 years old or 2.

2020: You'd be 4 years old or 1.

2024: Happy birthday! You're a newborn, and the Leap Day math does not apply to your age until the next Leap Year in 2028, where you'll be 4 years old and 1 in Leap Day years.

Countdown clock to Leap Year 2024. How many days until Leap Day?

Sangalang is a lead digital producer for USA TODAY Network-Florida. Follow her onTwitteror Instagram at@byjensangalang. Support local journalism.Consider subscribing to a Florida newspaper.