I’m a “quarter past” person but I’ve always been confused by “half ten” (which thankfully isn’t used in Australia). But in German, “half ten” means 9:30, which is make more sense to me (probably because I’m used to how German speech often drops words, which is less common in English)

Next, go to Germany or the Netherlands where half ten means 9:30.

I never heard that when I lived in the UK in the 70s, but only in Ireland in the late 90s.

Half ten? So.. 5. Got it.