How about March Fourteenth as "American PI-Day" and 22.07. as "international, sensible and widely understood PI-Day", each according to the used date format?
Fun fact: 355/113 = 3.14159...
Close enough to pi so that using it for calculating the earth's circumference from its diameter is accurate to within 3 meters.
I have a Daughter who was born on Pi day. When she was little. she would tell you it's the second most important day, right after Christmas. Pi Day actually became a school wide fun day because of her, (small rural schools can be fun that way). We would bring a couple of pies for her math class to celebrate. Oddly, she much prefers a strawberry cheese cake for her birthday over pies.
I suspect she will NOT allow the change...........