Маньяк

Пусть dtp1, dtp2 - дата и время "с", dtp3, dtp4 - дата и время "по".
dtp = TDateTimePicker. Тогда:
Код:
uses DateUtils;
procedure TForm1.ADOTable1FilterRecord(DataSet: TDataSet;
var Accept: Boolean);
var
DateFrom, DateTo : TDateTime;
begin
DateFrom := DateOf(dtp1.Date) + TimeOf(dtp2.Time);
DateTo := DateOf(dtp3.Date) + TimeOf(dtp4.Time);
Accept := (DataSet.FieldByName('dDate').AsDateTime >= DateFrom) and (DataSet.FieldByName('dDate').AsDateTime <= DateTo);
end;