Happy Pi Day! Don't forget to wear your Pi Day t-shirt! March 14 is celebrated as Pi Day because the date, 3/14, is the first three digits of pi, the ratio of a circle's circumference to it diameter. Of course, the number is not "round" at all, and the digits go on to infinity. In that long sequence of numbers, you'll eventually find any other sequence of numbers, like your birthday. Time made a handy calculator to find where your birth date falls in the pi sequence. Mine starts at digit 977.
That's pretty far in, but yours may go further. Albert Einstein's birthday starts at the very first digit of pi, because he was born on March 14, 1879. Einstein's birthday gives math and science nerds another reason to celebrate Pi Day, traditionally by eating pie. Pizza pie is included. Some restaurants and other businesses are offering special deals for Pi Day.
(Image generated at Hetemeel)