typedef struct _TIME_ZONE_INFORMATION {
LONG Bias;
WCHAR StandardName[32];
SYSTEMTIME StandardDate;
LONG StandardBias;
WCHAR DaylightName[32];
SYSTEMTIME DaylightDate;
LONG DaylightBias;
} TIME_ZONE_INFORMATION, *PTIME_ZONE_INFORMATION;

DWORD GetTimeZoneInformation(
LPTIME_ZONE_INFORMATION lpTimeZoneInformation
);

DECLARE INTEGER GetTimeZoneInformation IN kernel32;
STRING @lpTimeZoneInfo

I have an example here
http://www.news2news.com/vfp/?example=73&function=106
Just a basic one, parsing of returned buffer has to be added.

MSDN link:
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/sysinfo/base/gettimezoneinformation.asp