Re: Dates
"...So is 22nd of July 'Pi Approximation Day' in DD/MM countries then?"
I will be making a pie (Key Lime) for my family to celebrate today. I don't expect to get them to join me in singing a few rounds (which are, of course, the traditional music for Pi Day, similar to carols for Christmas).
https://projectpluto.com/temp/pi_rounds.pdf
My wife and daughter do not, in general, really get into the holiday spirit; Pi Day is more part of their nerdly husband/father's cultural heritage. But they'll eat the pie.
But a couple of years ago, my wife made some quite tasty quiches for 22/7. A quiche is, of course, "approximately" a pie.