How Many People Have The Same Birthday As You?

Getting all of those Facebook messages on your birthday certainly makes you feel special, right? It is a nice little ego boost to have your social media feeds blowing up on your big day. But do all of those “Happy Birthday” texts, cake emoji, and embarrassing throwback photos make you wonder how many other people are celebrate their birthday? Matt Stiles, a journalist who focuses on data analysis and visualization, wondered how common it is to be born on each day of the year. When a friend posted a birthday data table from the New York Times on Stiles’ wall, he got curious and started working on a visualization of the collected data. The result is this cool heat map, originally shared on The Daily Viz and reposted by Laughing Squid, that ranks each day by how common it is for a birthday. The darker the color, the higher that day ranks from 1 to 366 in birthday popularity. (Stiles clarified the shades in a follow-up post to his original heat map.) Just looking at the colors, it seems that summer and early fall rank the highest in birthdays. Do the math: that means that a lot of baby-making goes on during the cold winter months. Makes sense, right? Lots of time spent inside, cozying up by the fire, and all that. While the shaded heat map makes the differences between the days look drastic, Stiles was quick to point out that it is simply part of the visualization of the data and the rankings. The data shows that birth rates don’t vary all that much from month to month. “Alas,” he writes. “All our birthdays are probably pretty normal.” So, no matter when you celebrate, it probably isn’t all that unique. But you still get to feel special.