yoshito_umaoka@us.ibm.com writes:
Windows used to support only a pair of DST start/end rules per zone, but MS finlally implemented a framework for supporting historic changes since Windows Vista.
That URL says that the framework isn't implemented yet. The server side is scheduled to go out in Windows Server 2008 (aka "Longhorn"). Also, as far as I can tell, the client side supports only one rule change. For example, in the US a single Vista setting might support both 1987-2006 and post-2006 time stamps, but it wouldn't also support pre-1987 time stamps. At least, that is what I think <http://msdn2.microsoft.com/en-us/vstudio/bb264729.aspx> says (it's a bit hard to follow). I don't use Vista so I can't easily verify this myself, but if this information is incorrect, please let us know, as the Wikipedia entry <http://en.wikipedia.org/wiki/Daylight_saving_time#Microsoft_Windows> should get corrected. Let's hope that some day Microsoft will catch up to what the public-domain tz code was doing back in 1986. (Good work, Arthur!)