IMO the worst is that cal starts weeks on Sundays for some weird reason.
It's a bit like decimal point vs. decimal comma. Neither is inherently better, but man would it have been nice if we'd all picked the same one.
No disagreement there!
Related, but a few years ago the Norwegian broadcaster NRK asked people how the visualize a year. https://nrkbeta.no/2018/01/01/this-is-what-the-year-actually... (English version)
Quite interesting how different people are. Mostly it's a clock of sorts. To me however it's more of a sine wave, where each year is one phase (summer on bottom), but it's kinda fractally so if I zoom in it got bumps for the months, smaller bumps on there again for the weeks etc.
I wonder if visualizing a year as a circle is a particularly Norwegian thing, or if I’m the odd one out anywhere…
Back to the subject of which day the week begins: I’d say the fact that the week begins on Sunday doesn’t have much of a meaning in US culture, if any. If I say “next week” at work, it clearly means “the next M-F period”. If I wanted to refer to Saturday and Sunday I’d say “this weekend”. So if what I normally mean by a week begins on Monday and ends on Friday, you have to slot the weekend on one of those ends, and it feels slightly wrong whichever way you do it.
So, the only practical, concrete way in which “the week starts on Sunday” means anything to Americans is that we are used to seeing calendars printed with Sunday on the left, and Saturday on the right. I continue to maintain that this is arbitrary! But it does make me really confused when I have to use a calendar widget in an interface that wasn’t localized, and starts with a day other than Sunday, so I get your frustration.
The real question is why the weekend was defined as straddling the last and first days of the week. Weird.