Change system time zone

Hi experts,

Is there any EASY way to change Windows' time zone through the registry?  I found the registry key with the time zone information...
"HKLM\SYSTEM\CurrentControlSet\Control\TimeZoneInformation"
but it doesn't seem to be easy to manipulate, because of all the names, etc... that also need to be set when changing the time zone (not only the bias).

Is it easier to use the SetTimeZoneInformation WinAPI call to change the system's time zone?  Can anyone give me some sample code on how to change the date, time, and time zone using this function?

Thanks,
dannyguindi
dannyguindiAsked:
Who is Participating?
 
mokuleCommented:
Hi
Look there
http://17slon.com/gp/gp/gptimezone.htm
and there
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/sysinfo/base/settimezoneinformation.asp

and here how You can use the function

var
  tz: _TIME_ZONE_INFORMATION;
begin

GetTimeZoneInformation(tz); // to check current settings

// UTC = local time + bias + standard bias
// or
// UTC = local time + bias + daylight bias

tz.Bias := -60;

FillChar(tz.StandardName,sizeof(tz.StandardName),#0);
// can set any string
StringToWideChar('Standard Time',tz.StandardName,sizeof(tz.StandardName));
tz.StandardDate.wYear := 0;
tz.StandardDate.wMonth := 10;    // October
tz.StandardDate.wDayOfWeek := 0; // sunday
tz.StandardDate.wDay := 5;      // means last week of month
tz.StandardDate.wHour := 3;
tz.StandardDate.wMinute := 0;
tz.StandardDate.wSecond := 0;
tz.StandardDate.wMilliseconds := 0;
tz.StandardBias := 0;

FillChar(tz.DaylightName,sizeof(tz.DaylightName),#0);
StringToWideChar('Summer Time',tz.DaylightName,sizeof(tz.DaylightName));
tz.DaylightDate.wYear := 0;
tz.DaylightDate.wMonth := 3;     // March
tz.DaylightDate.wDayOfWeek := 0; // sunday
tz.DaylightDate.wDay := 5;      // last week of month
tz.DaylightDate.wHour := 2;
tz.DaylightDate.wMinute := 0;
tz.DaylightDate.wSecond := 0;
tz.DaylightDate.wMilliseconds := 0;
tz.DaylightBias := -60;

SetTimeZoneInformation(tz);
0
 
dannyguindiAuthor Commented:
Just what I needed.  Many thanks.
0
 
mokuleCommented:
I'm happy to help :)

Marek
0
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