var d1: System.Nullable<Double>;
      var d2: System.Nullable<Double>;

      d1 := new DateTime(2018,5,1).ToOADate;
      d2 := new DateTime(2018,5,18).ToOADate;

      try
        var  HistMain := (from apr in fDataModule.DataAdapter.GetTable<aprecon>
                          where ((apr.StartDateTime >= d1) and (apr.StartDateTime <= d2))
                          where (apr.PostDateTime<>0)
                          select apr).ToList;

        Console.WriteLine('Recons returned: '+HistMain.Count.ToString);