title: .NET DateTime.Now returns incorrect time when time zone is changed
body: <p>This problem occurred during daylight saving time change. After the change occurred, we've noticed that our server application started writing into the log incorrect time - one hour ahead which means that .NET caches time zone offset. We had to restart our application to resolve this problem.
  I wrote a simple application to reproduce this problem. When I change the time zone while application is running, DateTime.Now property keeps producing the time in the old time zone.
  Does anybody know if there is a workaround for this problem apart from restarting the application?</p>