Title: Set the system time and date
Use SystemTime structure for changing system date and time, and then use SetSystemTime procedure to set them into the system.
procedure TForm1.Button1Click(Sender: TObject);
var
dt: TSystemTime;
begin
dt.wYear:=1999;
dt.wMonth:=2;
dt.wDay:=25;
dt.wHour:=9;
dt.wMinute:=0;
dt.wSecond:=0;
dt.wMilliseconds:=0;
if SetSystemTime(dt) then Label1.Caption:='Setting finished';
end;