Using our American date format, today is 3.14.2008. Since the mathematical constant, pi, truncated to seven digits is 3.1415926, many people celebrate today at 1:59 PM (and 26 seconds after the minute) on Pi Day. The idea for celebrating Pi Day started in 1988 at the Bay Area's own San Francisco Exploratorium. My son is actually bringing a pie to his high school math class today. Enjoy the day!