The relationship of March 14th to Pi is dubious at best. It’s merely happenstance that the digits of the month number for March line up with the first digit of pi.
The important fact of pi is it relates the circumference of a circle to its diameter.
We can measure angles in radians, which is a natural measurement system where an entire circle, 360 degrees, is 2 pi radians. In other words, the arc length for an angle is equal to that many radians for the unit circle.
The earth traverses 1 radian in about 58 days. The 58th day of the year is February 27th. We should celebrate that day as pi day. It has a much greater relationship to pi than March 14th.