date change

Hey,
I have a little problem with my program, it should change the date to (somedate) run a program, wait 5s and change it back.

Tom

--snip--

procedure TForm1.FormCreate(Sender: TObject);
var
myDate,newDate : TDateTime;
myYear, myMonth, myDay : Word;
begin
DecodeDate(myDate, myYear, myMonth, myDay);
myDate := StrToDate('04/24/2003');
WinExec('c:\bin\date', SW_SHOWNORMAL);
Sleep(5000);
newDate := EncodeDate(myYear, myMonth, myDay);
ReplaceDate(myDate, newDate);

//myDate := RecodeDate(myDate, myYear, myMonth, myDay);
Application.Terminate;

end;
T0maszAsked:
Who is Participating?
 
Russell LibbyConnect With a Mentor Software Engineer, Advisory Commented:
An example:

procedure TForm1.FormCreate(Sender: TObject);
var  myOldDate, myDate:   TDateTime;
     dwMark:              LongWord;
     sysTime:             SYSTEMTIME;
begin

  // Persist the current date
  dwMark:=GetTickCount;
  myOldDate:=Now;

  // Example date setting
  myDate:=StrToDate('04/24/2003');

  // Decode the date (use the current time)
  with sysTime do
  begin
     DecodeDate(myDate, wYear, wMonth, wDay);
     DecodeTime(myOldDate, wHour, wMinute, wSecond, wMilliseconds);
  end;

  // Set the time
  SetLocalTime(sysTime);

  // Do whatever
  // WinExec('c:\bin\date', SW_SHOWNORMAL);
  Sleep(5000);

  // Update with the number of milliseconds that we were delayed
  dwMark:=GetTickCount-dwMark;
  myOldDate:=myOldDate+(dwMark / MSecsPerDay);

  // Reset the date time
  with SysTime do
  begin
     DecodeDate(myOldDate, wYear, wMonth, wDay);
     DecodeTime(myOldDate, wHour, wMinute, wSecond, wMilliseconds);
  end;

  // Set the time
  SetLocalTime(sysTime);

  // Finished
  // Application.Terminate;

end;

The dwMark variable (seeded with GetTickCount) is used for keeping track of how many ms elapsed while the time was changed.

Hope this helps,
Russell

0
 
Ivanov_GCommented:

   You do not replace the system date ...

   use the API SetLocalTime

   example :

procedure TForm1.Button1Click(Sender: TObject);
var
  SysTime : TSystemTime;
begin
  with SysTime do
    begin
      wYear         := 2004;
      wMonth        := 4;
      wDayOfWeek    := 3;
      wDay          := 4;
      wHour         := 20;
      wMinute       := 51;
      wSecond       := 0;
      wMilliseconds := 0;
    end;
  SetLocalTime(SysTime);
end;
0
 
Ivanov_GCommented:

  use can use also this function to convert TDateTime to TSystemTime and back

  function SystemTimeToDateTime(const SystemTime: TSystemTime): TDateTime;
  procedure DateTimeToSystemTime(DateTime: TDateTime; var SystemTime: TSystemTime);
0
 
T0maszAuthor Commented:
Thanks to all of you, but rllibby was the closest one, plus I really dont like using TSystemTime because you have to put all the parameters date,time so on and on one station it didnt work correctly for some reason.

Tom
0
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