I go further out of my way to do everything in ISO dates, and if a system allows it I set my timezone and locale to Iceland which is UTC, and that really screws with people.
If I'm typing stuff it's generally 2023-01-01 to avoid doubt. If it's in our systems, well, we're fucked. Soooo much time and effort spent on date conversions!
This. I make a point of using EU sizing in all my dealings with shoes because it avoids confusion.
I hate: GB AU US shoe sizing and the Amerian date format idiocy