Thanks to this handy infographic created by NPR data journalist Matt Stiles, we now know that babies are most commonly born in September. Count backwards by nine months and you’ll learn that baby-making typically occurs during the winter holiday season, which isn’t terribly surprising. After all, there’s not much else to do when it’s cold outside. So how common is your birthday?

The infographic is based upon data compiled by Harvard Kennedy School professor Amitabh Chandra, which uses birth date information from 1973 to 1999. Chandra’s findings were originally published in the New York Times in 2006.

Interestingly, the most popular birth date is September 16th, with February 29th as the least popular. Where does your birthday fall in the rankings?