Sounds as if the internal clock is a bit off. Sorry - I misunderstood; I thought it just wasn't keeping track of your time zone.
I haven't needed to use the time function of the Kindle - with a watch and computers and other time pieces around, I haven't had the need to check the time via the Kindle. This internal clock problem, however, may indicate other problems with your unit; after all, it is a computer so it could be that other processes in the unit depend upon it having an accurate clock. Calling Kindle CS is probably a good idea.
Since you are in Germany, do you think you will have to pay for shipping and taxes, etc.? I bet that's not cheap but won't Amazon pick up at least part of the tab since the unit is faulty? One can only hope.
Holly