The above graph is from a few years ago but is particularly relevant today!

It’s funny that, in leap years, approximately 10% fewer babies are born on 29 Feb. I think it would be cool to have a Leap Day birthday. But I guess most people, not being nerds, would prefer the less-“weird” days before and after.

There’s lots of good stuff at the above link; I encourage you to read the whole thing.

In the years since, we’ve improved Stan so we can fit and improve the birthdays time series decomposition model using full Bayesian inference.

Here’s Aki’s birthday case study which has all the details. This will also be going into our Bayesian Workflow book.