Annabella Gualdoni of Brookline will celebrate her 14th birthday this year, but she’s really turning 56. And Jeff Johnson of Amesbury is celebrating his 17th birthday, but he’ll really be 55.

They’re both “leap year babies” — people, who in 2024, will get the opportunity to mark their rare birthday on the day itself. February 29, with a few exceptions, only comes around every four years — and it's a birthday that presents occasional bureaucratic challenges and spawns plenty of jokes.

“You have everybody saying ‘ah, you don’t have a birthday. No birthday for you this year.’ You know, family members, it was a big joke.” said Johnson.

People have told Gualdoni, “that day doesn’t exist.” A friend suggested she celebrate on two days — February 28 and March 1 — when there’s no 29th.

“I do now, mostly just to give my husband a hard time that he has to be nice to me for two days instead of just one,” laughed Gualdoni.

Charlestown resident Callen Chambers is turning 4 this year. He has no doubt about what he wants to do on his first leap year birthday.

“Eat cake!” he said.

Callen’s mom Shannon Chambers said her son doesn’t mind all the jokes about turning 1.

“I feel like we’re still at the age where we’re still counting, like ‘I’m 3-and-a-half’ so everything counts,” Chambers said.

The unique birthday can present some bureaucratic obstacles and opportunities. Massachusetts drivers with a leap year birthday get an extra day to renew their drivers license. But navigating online systems can be a challenge when February 29 doesn't appear on a calendar.

There are few instances where state law mentions a leap year birthday, but interestingly elevator operators have been taken into account. State law says that the license of an elevator operator born on February 29 must expire on March 1.

It’s not something that comes up often in law or regulations, said Damian Turco, president of the Massachusetts Bar Association.

“If you don't have a leap day birthday and no one in the room does, maybe this isn't something everyone's thinking about when they're drafting the law or drafting the regulation,” said Turco.

It’s not surprising since leap year births are comparatively rare.

In 2020, the last leap year in Massachusetts, there were only 164 babies born on February 29, out of a total of 67,220 total births in the state that year. That’s less than .2 percent of all births.

Leap year babies born in the state in 2004 were even more rare — only .16 percent of all births that year, according to the Massachusetts’ Registry of Vital Records and Statistics, which provided leap year stats going back to 1969. Those born in 1972 were in a relative leap year crowd, with just over .3 percent of all births born on February 29.

For some people, it's a family affair. Somerville resident Monica Rajan has an unusual family cluster of leap year babies: In addition to herself, she has three relatives who were all born on February 29. But rare or not, Rajan thinks everyone should revel in the day that doesn’t happen every year.

“I always just encourage people to, you know, do something special with the day,” said Rajan who is turning 8 (or really 32). “You get an extra 24 hours, right? So why not have fun with it?”