## Leap Day Birthdays

In my Leap Day contribution to the New York Times Learning Network, “10 Activities for Learning About Leap Year and Other Calendar Oddities,” I calculated the odds of a person having a Leap Day birthday.

Assuming each day of the year is an equally likely birthday, and noting that there is one Leap Day every four calendar years, I calculated the probability to be

(Leap Day Birthday) = $\frac{1}{4*365 + 1} = \frac{1}{1461} \approx 0.0068$

or around 0.7%.

So how many people with Leap Year birthdays do you know?