And you are sure it was German, not Dutch? Also, what kind of radio are you using and could you have the freq off by 1 kHz? Depending on the radio it can sometimes be difficult to find the exact center freq of an AM signal, peaking the signal by ear will not always result in the true center freq.
Radio Nederland out of Bonaire in the Antilles broadcast on 6165 kHz in Dutch from 0400 to 0427 UTC, and that should have been 2300 to 2327 (1100 PM to 1127 PM) local for you.
The time is right, Dutch is pretty close to German to a person who does not speak the language, and the freq is about right. So my bet is it was Radio Nederland.