One is a teacher. One is an athletic trainer. One is a toddler.
At first glance, Linda Potsiadlo, Allie Hammond and Landon Westerlund may not appear to have much in common. But they all share a birthday — a birthday that only happens once every four years.
Potsiadlo, Hammond and Landon are Leap Year babies — all born on February 29.
Only about one in every 1,461 babies born in the world are born on Leap Day — an event that occurs every four years because of accumulated time the Earth takes to revolve around the sun — which makes the bond Potsiadlo, Hammond and Landon share all the more special.
"It's just fun; it's unique," said Potsiadlo, 63, of Columbia and a teacher at Murray Hill Middle School in Laurel. "I feel like an ordinary person the rest of the time, so it's nice to have one unique thing about yourself."
By Leap Year standards, Landon is turning 1, Hammond is turning 7 and Potsiadlo is celebrating her Sweet 16.
"When your birthday does come around, it has such a feel to it," Potsiadlo said. "When it's really your birthday, you're just not used to that feeling."
Having a birthday on a day that only exists once every four years was a baffling concept growing up, Hammond said, but now, it's other people that get confused.
"Explaining it to the high school kids, they don't understand," said Hammond, 27, of Woodlawn and an athletic trainer at Wilde Lake High School in Columbia. "...I asked a student if he even knew what Leap Year was, and he said it was 'when the moon flipped,' so there you go ... some just don't get it. It can get hard to explain."
During the in-between years, Hammond recalled watching the clock tick down to midnight on Feb. 28, only to see her birthday get skipped over. Potsiadlo agreed, adding that it sometimes felt like she was cheated out of birthdays.
"It's just that there's no day, no birthday, even though you have a marker for turning another year older," Potsiadlo said. "It's a marker, but it's not a birthday."
But when their birthdays do come, everyone remembers.
"It absolutely makes people remember you," Hammond said.
They all celebrate their birthday in different ways. This year, Landon's looking forward to an Angry Bird cake and the basketball he asked for. Potsiadlo's husband and her neighbors take her out for a "Happy 29th Hour." Hammond's family has age-corresponding birthday parties — this year, her family will get her balloons and cards that say "Happy Seventh Birthday."
But they always celebrate on the same day, even during the years that their birthday doesn't exist.
"That's always the first question," Hammond said. "'When do you celebrate?' Celebrate the 28th. Or all week."
The way Potsiadlo sees it, her birthday is in February, so she celebrates in February.
Celebrating his birthday on Feb. 28 makes even more sense for Landon — it's his mother's birthday.
"It makes it easier, and it makes it special for us because we kind of share the same birthday," said Alexis Westerlund, 25, of Ellicott City.
Westerlund said her father had wanted her to be a Leap Year baby, and for years, he teasingly insisted that she was in fact born on a Leap Day. But with Landon, he got the real deal.
"Everyone said he was going to come on Feb. 29," Westerlund said. "He was due on March 15, but he was ready. I was ready ... when I finally got Landon, I said 'Here Dad, you got one.' "
Landon, 3, knows his family members' birthdays in order, Westerlund said — most are in February — and he knows his comes last.
"He knows that his day is a special day," she said. "He knows he can't always find his birthday on the calendar."
Like Hammond and Potsiadlo, but not in so many words, Landon understands the uniqueness of his birthday.
"It's just fun," Landon said. "It's funny."