Which would still be really strange and not understood by most Brits (source: am Brit)

In old-ish French (spoken by my grandparents' generation in some parts of Belgium), you can still hear "la demie de 2 heures" and "le quart de 7 heures", which directly translate to "the half of 2 hours" and "the quarter of 7 hours". They in fact mean 1:30 and 6:45! (am or pm depending on the context).

Also in current Dutch, at least as spoken in Belgium aka Flamish, we say "half twee" which means "half two" and refers to 1:30.