square root, pi day, dzień pierwiastka kwadratowego, square root symbol, world math day. Square root day is a humorous holiday celebrated on dates where the day and the month are both the square root of the last two digits in the current year. Like the latest square root day is March 3, 2009 (3/3/09), and the next square root day will be April 4, 2016 (4/4/16).
The final square root day of the century will occur on September 9, 2081. Each century it is the same nine dates that are Square root days.
What History behind square root day?
Ron Gordon, a Redwood City, California high school teacher, first created the day for 9/9/81. Gordon is the official public relations person and sends news releases to world media outlets.
How to celebrate Square root day?
One suggested way of celebrating the holiday is by eating square radishes, or other root vegetables cut into shapes with square cross sections.
Suggested activities on Square Root Day include drinking root beer out of square glasses, tying a square knot and eating root vegetables that have been cut into squares. Gordon is also holding a Square Root Day contest to involve the most people in a Square Root day celebration, including having people gather to make the shape of a square root symbol.
About Pi Day
March 14 or Pi Day, where 3/14 symbolizes 3.14, the number used to formulate the ratio of a circle's circumference. But pi day in not in the list of Secular holidays like Square root day.

"These days are like calendar comets, you wait and wait and wait for them, then they brighten up your day — and poof — they're gone," said Ron Gordon,
What is square root symbol?
In mathematics, a square root of a number x is a number r such that r2 = x, or, in other words, a number r whose square (the result of multiplying the number by itself) is x. 3/3/09: Math fans to celebrate Square Root Day and the square root symbol as \sqrt{x},