A very happy Pi Day to you! Did you know that our celebration of pi this year is a special once-in-100-year occasion? We celebrate Pi Day on 3/14 because those are the first three digits of pi - 3.14, but this year 3/14/15 will include the first five digits of pi - 3.1415. In fact, at 9:26 and 53 seconds we will have the first 10 digits of pi - 3.141592653. That's a lot of pi!