No, these usages specifically don't use "vor" and "nach". Presumably idiomatic spoken German

You can modify your system date format to iso, then it works.

Either by modifying your locale files, or by using one of the few locales that use iso, like en_SE. You can set this only for time strings by using LC_TIME (kde supports this in its settings graphically).

I like that this includes the weirdness around using 12 instead of 0 for hours

viertel vor/nach zwölf bitte schön.

date -d, but limited.

I think those require a "vor" and "nach" respectively.
"viertel zwölf" seems to reliably mean 11:15 unless maybe it's a casual shortening both sides are aware of. If you go to a random person and tell them viertel zwölf they probably won't understand, but if they do they should think 11:15.

"viertel zwölf" (quarter twelve) = 11:15
"viertel vor zwölf" (quarter to twelve) = 11:45
"viertel nach zwölf" (quarter past twelve) = 12:15

I think that in some parts of Germany, viertel zwölf means 12:15, but in others it means 11:45. Just to keep things interesting!

I learned the latter near Frankfurt, 40 years ago, and the former in Eastern Germany this year.

Yes, I forgot about that 😅

And the 2038 thing, that's another one 🙄

Bravo.

"viertel zwölf"

quarter twelve

archaic runes I cannot hope to comprehend

I am however assured by sources it means 11:15

edit: switched :45 to :15 examle as it is even worse

Linux: lol

Yes, very minor. I’ve never heard anyone using it.

Let's for the sake of sanity assume these are only ever written down never pronounced.
Else one and the same notation would perform differently based on who is reading it.

Germany if memory serves has a minor movement advocating use of "twenty-eight" instead of "eight-and-twenty" for example.

Edit: English isn't exactly innocent either with their teens, german at least is consistently inverted. The hundreds and thousands however could be inverted with nine-teen-hundred or could be correct with one-thousand-nine-hundred

Now remember how fucked-up numbers are represented in different languages, for instance eight-and-twenty in German, and you can shove these nice stacks through the blender once more.

The way I look at it, if I were looking for a date in a calendar, I’m not going to start with the day, find the day and look for the right month, then look for the correct year. I’ll start with the year I’m looking for, go to the correct month, then finally locate the day in question.