As you may know, it is my firm and unflinching belief that our math & science “holidays” should be scheduled so that they actually teach something about the number being celebrated. Sure, 3.14 is a reasonable estimate of π, and March 14th does represent that number in typical US calendar notation (which has no respect for the hierarchical organization of dates).
But, that says nothing about what π represents. It represents the relationship between the radius (r) of a circle and both its circumference (C=2πr) and area (A=πr2). When it comes to expressing this relationship using dates, I prefer circumference because both the radius and circumference are lengths. Also, expressing the year as a circle makes sense to me (and, based on their mythologies, a large number of human cultures).
If C is 365.25 days and π is π, then 2r is approximately 116 days, which makes r approximately 58 days.
Which is why, at The Finch & Pea, 27 February is Pi Day.