@Doctor Who:

According to this timeline, Microsoft has been unable to in over 10+ years fix a bug affecting this sort of scenario:

http://www.cl.cam.ac.uk/~mgk25/mswish/ut-rtc.html

http://support.microsoft.com/kb/2687252

The bug is that the computers clock should be set to a known reference time like UTC that does not observe DST, yet Windows is incapable of properly handling this scenario because Microsoft has made the assumption that normal users go to BIOS and manually set the RTC to local time. I would say that is a correct assumption, but only in cases where the users computer is in a fixed location.

How many years does it take for Microsoft engineers to fix a bug? Well 10+ years and counting we can say that for sure.