Uh? But that's completely besides the point. Windows provides timezone offset information in a different way than Linux does (through the Registry) but it's still available. It's trivial to do in .NET for example:

    Console.WriteLine(TimeZone.CurrentTimeZone.GetUtcOffset(DateTime.Now));

Aren't a lot of things implemented differently in Linux and Windows? I'm not familiar with Python's internals, but I'm sure a lot of functions are implemented differently cross platform. This bug is certainly valid, as any code using this function will not work as expected on this platform.