[Zhigalov]

А если так?

Код:

procedure TForm1.Button6Click(Sender: TObject);
Var Filter:String;
begin
      Filter  := 'Число>='''+DateToStr(DateTimePicker1.Date)
      +''''+' and '+'Число<='''+DateToStr(DateTimePicker2.Date)+'''' ;
  ADOTable1.Active:=False;
  ADOTable1.Filter := Filter;
  ADOTable1.Filtered := true;
  ADOTable1.Active := true;
end;