Setting LOCALE settings

Is there a way to tweak the locale info?

I need to set this desktop to comport with ISO-8601 - can’t find this option anywhere in the Linux stack to begin with.

Typical suggestions have been to use en-CA, en-DK or en-SG, but these all have issues, such as incorrect currency or paper formats.

I can set it to either of those, but Budgie does not seem to have an option to set the out-of-place value.

If I’m not mistaken, you should be able to configure some stuff separately in /etc/locale.conf.

I used it to get en_us without having the start of the week on Sundays (why? But why?).

Here’s a link to some wiki giving you more info.
I think (but am not sure) you can set your ISO-8601 in there. Or maybe use LC_MONETARY.