James Roberts of Milltown laughs remembering how he got rejected for a credit card.

"They said I wasn't old enough," he said. "The computer thought I was 9."

Born 52 years ago and celebrating his 13th birthday today, the Valero oil refinery operator is among the ranks of folks with Leap Day birthdays who say the special day deserves more respect.

He's among more than a dozen Delaware members of the international Honor Society of Leap Day Babies, which offers free software to fix computers' Feb. 29 date-recognition problem, like the one that denied him a credit card.

The group, more than 6,000 strong, also is campaigning to get calendar makers to label "Leap Day" instead of just sticking another dated box at the end of the month.

Famous people from Pope Paul III to motivational speaker Tony Robbins to serial killer Aileen Wuornos share the Feb. 29 birthday. And, according to Time magazine, Superman's birthday was Leap Day.

"Comes every four years, like the summer Olympics and presidential elections," Roberts said, adding with a laugh, "two out of three ain't bad."

Like Roberts -- now at "an age where celebrating a birthday every four years is plenty" -- fellow Leap Baby Loretta Iezzi-Farkas, an engineer who lives in Middletown, ran into birth date snags.

"Especially at the beginning of the computer era," she said. "I got sick of having to go explain to them that Feb. 29 does exist."

And it has since 46 B.C., when Roman Emperor Julius Caesar created the day to make up for a solar year running about 365 1/4 days, says the Royal Greenwich Observatory, which puts the actual length of a year at 365.24219 days. A 1582 tweak by Pope Gregory XIII got more accurate timing by cutting out Leap Day in century years not divisible by 400.

Recently, the day came under attack by computers -- also accused of denying some Leapers driver's licenses. A YouTube video urges its abolition.

Still, Iezzi-Farkas and Roberts like their rare birthday. "I don't know what the odds are," he said, "but I'm sure it's a pretty small chance."

Tom Ilvento, who chairs the University of Delaware's statistics program, says the odds are 1 in 1,464 or 1 in 1,461, not counting the factor of century years being skipped to make up for odd minutes of the solar year. Some say that cuts the odds to about 1 in 1,500.

Ilvento calculates that a person is more than 400 times more likely to be born on Leap Day than to be hit by lightning (about 1 in 600,000) and about 10,000 times more likely to have that birthday than to win Powerball. Of 560,458 Delawareans registered to vote, 418 list Feb. 29 as their birthday -- about 1 in 1,340. Nationwide, there are said to be about 200,000 Leap Babies, and more than 4 million worldwide.

Many Delawareans will have Feb. 29 printed on their birth certificates today at Christiana Hospital alone. "In 2004, there were 15 babies born on Leap Day and in 2000, there were 24," said Christiana Care spokesman Spiros Mantzavinos.

Despite database problems that can be aggravating, Mary Frances "Fran" Nichols of Dover said she feels lucky to be a Leap baby like her great uncle. "I'm very proud of it," said Nichols, who said she is "hitting the big 11."

Recognition of one Leap baby's first birthday surprised parents Tobias J. and Erica Paquette, who live near Lincoln.

Their son Tagen's birthday four years ago was a surprise, his father said, because "he wasn't due until March 19." But a TV crew visit before his first "real birthday" today was an unexpected perk he said left the boy "a little befuddled, like, 'What's the big deal?' "

Beyond issues of computers and when to celebrate, Leap Day can cause awkward social shock.

Imagine how conversation halts when Leap baby Karen Hessler of Newark and her husband, Bill, say their engagement party was on her seventh birthday. Or that by her eighth, she was pregnant with their second child.

"My favorite story from when I was little was my dad telling his co-workers that his daughter could dress herself and use the potty and hadn't even celebrated her first birthday," she said.

People just don't think of the day, say Roberts and Iezzi-Farkas. When she says her birth date, Iezzi-Farkas said, most people immediately say, "There is no Feb. 29."

"It's comical and funny," she said. "Seventy-five percent of the people don't get it."

Odd birthdays, however, run in Roberts' family.

A cousin was born July 4, aunts on Christmas and Halloween. His grandmother was born on Valentine's Day and married a man whose middle name was Valentine. And her best friend? A Leap baby.

As he celebrates his "real birthday" tonight with dinner and shooting pool with friends, Roberts expects to say what he always does.

"I tell everybody that every day I have a birthday," he said, "they get an extra day to live."