Einstein was born on Pi Day, March 14, i.e., 3/14. You may have noticed that today is not 3/14, and perhaps you are wondering whether it might be Pi Approximation Day instead. No, that would be July 22 (as in 22/7, Archimedes' approximation of Pi).
Today's celebration is relativistic! Somewhere in the space-time continuum, today is 3/14!
And anyway, relativistic space is non-Euclidean, so, this means the physical Pi doesn't always equal the mathematical Pi–that is, the ratio of circumference to diameter is not constant as it would be on a perfect plane—it varies with the curvature of space.
So, Happy Birthday, Pi, and Happy Birthday to the physicist who made us think of Pi in a different way.
Bottom: Portrait of Albert Einstein, Scientific Identity: Portraits from the Dibner Library of the History of Science and Technology, 2003