Live: Amazon Event Wednesday Probe Crashes Into Asteroid Prime Day 2: Oct. 11-12 Tesla AI Day Hurricane Ian Satellite Images Save on iPad Pro Refurbs Apple Watch Ultra Review EarthLink Internet Review
Want CNET to notify you of price drops and the latest stories?
No, thank you
Accept

Here's why Saturday is a very special Pi Day

Every March 14 celebrates math's most famous irrational constant, but this year is different.

Whether or not you're a math geek, you know pi, or at least the beginning of it: 3.14. The infinite, irrational constant, without which you couldn't find the area of a circle, gets its day each year on March 14 (3/14).

But this year is special.

If you stretch out pi to its third and fourth decimal places, you get 3.1415, making March 14, 2015 (3/14/15) the ultimate tribute. And unless you're 117-year-old Misao Okawa, the world's oldest person, it's a once-in-a-lifetime event. It won't happen again until the year 2115.

Whether you are celebrating with a math marathon or a pie-eating marathon (or a combination in which you use pi to figure out how much pie you just ate), if you really want to do it up this year, plan something for 9:26 and 53 seconds, stretching your commemoration all the way out to 10 digits.

This story originally appeared on CBSNews.com.