John Conway is most famously known for "Conway's Game Of Life" - but he published a whole lot more. One especially remarkable algorithm he developed around 1970 is the Doomsday rule.

The name may sound a little odd, but the algorithm is amazing: It allows you to calculate the day of the week for any given date in your head.

In this post I will explain how this algorithm works and do a practical example in PHP.

Read the full article on dev.to!