Hey Chris,
thanks for your quick reply.
I found another strange behaviour:
I am using the Method TimeService.SetTimeZoneOffset(int) to set the correct local time.
If I use DateTime.UtcNow() the kind of the instance is 'Local' instead of 'Utc', so I get the wrong time when I call DateTime.UtcNow().ToLocalTime().
I think this is a bug in NETMF -> I submitted an issue for this on NETMF-Project on Github.
Greets, Greg