[lorenzhs]

It's uncommon in personal settings, though, at least in German. If you call your doctor to make an appointment, they might ask you if "fifteen thirty" suits you, but when fixing a time for meeting your friends at a café you'd say "halb vier" (half four, which is 15:30 in Germany, but 16:30 in the UK. Yay confusion!)

[DocTomoe]

Actually, "Halb vier" (half four) can mean both in Germany, depending on which village you are in. It becomes even more confusing if you use something like "Viertel vier", which, depending on your village, can mean 15:15, 15:45 or 16:15.

This is why the less rural people over here use exact time.

[lorenzhs]

Citation needed! I've never heard anyone use the "half past" meaning. The quarter thing is confusing, though. While I have never heard of anyone parsing "viertel vier" as 15:45 or 16:15, many people are confused as it's somewhat uncommon here.

Not sure why you feel the need to imply people using "half" are somehow impaired (as the attribute "rural" is often used to imply backwardness). The "half" notation is ubiquitous in the south.

https://de.wikipedia.org/wiki/Uhrzeit#Sprechweise_im_Deutsch...