Mom and Daughter Had a 1-in-2.1-Million Chance of Sharing a Leap Day Birthday

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On February 29, 2008, Michelle Birnbaum gave birth on her own birthday, meaning that four years later, on the next Leap Day -- today -- we would get to read about how unlikely it was for this mother-daughter pair to share a February 29 birthday. David K. Li, writing in the New York Postprofiled Michelle, a New Jersey "lawyer for kids in child-welfare cases," and her 4-year-old daughter Rose for one of our favorite Leap Day-pegged pieces this year. Li also found someone far better at math than us -- Tufts professor James Ennis -- to calculate the odds of a parent and child like Michelle and Rose sharing a February 29 birthday. "Brushing aside huge variables such as seasonal birth rates, specific generational trends, and other man-made manipulations, the odds of a mom and child sharing Leap Day birthdays are 1 in 2.1 million," according to him.

We think those 1-in-2-million odds will be a nice thing for daughter Rose to brag about to her first- or second-grade classmates on her next "real" birthday, in 2016. After all, if having a plain old regular Leap Day birthday is unique -- February 29 is the least common birthday of the possible 366 -- a parent-and-child birthday sharing of that day is positively remarkable. Quirk aside, we're glad mama Michelle is using the day as something educational, given the weirdly dark Leap Day pieces this year: "Birnbaum hopes to use their Feb. 29 birthdays as a hook for science lessons, to help Rose learn about Earth’s annual trip around the sun that takes a little more than 365 days to complete," writes Li.

This article is from the archive of our partner The Wire.