It turns out today is the real labor day.

More babies have been born on Sept. 9 than any other day of the year, according to data compiled by statistician Nate Silver's site, FiveThirtyEight, based on registered births in the U.S. from 1994 to 2014.

New parents watching babies in hospital nursery Getty Images

The Daily Viz then put that data into a visual heat map that puts the data from the National Center for Health Statistics and the Social Security Administration in context.

Counting roughly nine months backwards, that puts the most popular date of conception around December 17 — right before the holidays and a nice time to be under the covers as the temperatures drop outside.

Actor Adam Sandler shares the most popular birthday, Sept. 9. Frazer Harrison / Getty Images

A less scientific metric is the sheer volume of famous people born on this date.

Four-time Oscar nominee Michelle Williams (1980) and three-time Razzie winner Adam Sandler (1966) share the birthday.

So do British actor Hugh Grant (1960) and Canadian crooner Michael Bublé (1975).

Hugh Grant also shares a Sept. 9 birthday. Getty Images

There are enough sports figures to fill an All-Star-caliber birthday party.

Among them, Cleveland Cavaliers star J.R. Smith (1985) and Super Bowl-winning quarterback Joe Theismann (1949) were born on Sept. 9.

Sept. 9 is very important date for J.R. Smith as well! Gregory Shamus / Getty Images Contributor

Legendary Russian author Leo Tolstoy (1828) and the late, great "(Sittin' on) The Dock of the Bay" singer Otis Redding (1941) were also born on the esteemed date.

And the real secret recipe behind Kentucky Fried Chicken? Whatever aphrodisiac Colonel Sanders' father fed to his mother nine months before September 9, 1890, when KFC founder Harland Sanders was born.

As Time Magazine points out, though, a previous Harvard University study looking at birth data between 1973 and 1999 pegged Sept. 16 as the most common birthday.

Regardless, the Daily Viz map confirms that September continues to be a very popular month to give birth to a child — and December, by extension, the most popular time to make one. The top 10 most common birthdays all fall in the first month of fall.