I asked someone to stop saying “half 5” as a time since it was ambiguous & confusing, especially given that we weren’t in an English-speaking country & folks come from all over (many culture this means one thing or the other, while many—including where I grew up—don’t even use it as an expression). I asked a few times, then another time we were gonna meet up, I asked him “half five ha” “so what time do you really mean?” “half 5” …so I just didn’t show up, wasn’t in the mood. We haven’t really talked since.