Code:

function DateExists(Date: string; Separator: char): Boolean;

var

OldDateSeparator: Char;

begin

Result := True;

OldDateSeparator := DateSeparator;

DateSeparator := Separator;

try

   try

     StrToDate(Date);

   except

     Result := False;

   end;

finally

   DateSeparator := OldDateSeparator;

end;

end;

procedure TForm1.FormCreate(Sender: TObject);

begin

if DateExists('35.3.2001', '.') then

begin

   {your code}

end;

end;

Code:

function ValidDate(const S: String): Boolean;

BEGIN

Result := True;

try

   StrToDate(S);

except

   ON EConvertError DO

     Result := False;

end;

END