Do you need the API call that would bring up the Date/Time Properties Dialog?
The code below brings up the dialog that you get when you double click on the time in the task bar.
function GetSystemDir: string;
var
SysDir: PChar;
begin
GetMem(SysDir, MAX_PATH);
GetSystemDirectory(SysDir, MAX_PATH);
Result := StrPas(SysDir);
FreeMem(SysDir, MAX_PATH);
if (Result[Length(Result)] <> '\') then
Result := Result + '\';
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
ShellExecute(0, nil, PChar(GetSystemDir + 'rundll32.exe'),
PChar('shell32.dll,Control_RunDLL Timedate.cpl'), PChar(GetSystemDir),
SW_SHOW);
end;