This is something I really hate in KDE- you choose date/time formats with a dropdown of flags, and it doesn't even give you a preview of the short format, so you have to cycle through hundreds of options and click-click-click each to find what you want, when all that's needed is [Language] + [yyyy-mm-dd HH:MM]* (or whatever) format string.

there are far fewer format options than countries, so this is an exercise in frustration

(*en_SE.UTF-8 btw)