>>I wouldn't call whole Nord-Rhine (no idea of Westfalia) as rural ... They always use a-quarter-from or a-quarter-to. The quarter / half / three quarters of the full hours system is completely unkown there.
>>If you say quarter-2. i.e. 13:15 the will ask: a-quarter-from or a-quarter-to
>>5-to-three-quarters-of-9 - a therm for 8:40 normal in Saxony - expressed in Cologne is fun.
>>
>>13:25 is a 5-before-quarter-after-quarter-2 in parts of the Ore Mountains. That's odd.
>
>OK, just to check how far have we diverged... what do you think "five to half six" is?

17:25 or 5:25
5 minutes to the half hour of 6

We count hours (the first, the second hour and so on) of the day, and express how many parts of this hour have passed. So to your other message
three quarters of 4 means 3/4 of the 4th hour passed, it's 3:45 or 15:45.
To our friends in North-Rhine we always say, that we count hours in the sense of full like a full glass. A quarter full, half full, three quarters full.
Also note that this does not work with hours above 12. Normally the context is enough.