9% of the worlds birthdays happen in August, making it the most popular birth month.
In the u.s. more people are born on October 5th than any other day. May 22nd is the least popular besides leap year February 29ths obviously.
There's an average of 15 million people celebrating a birthday every day.
Out of 23 people, there is a 50/50 chance 2 of them have the same birthday. The probability goes up to 99% when you have 57 people.