public static Tuple2 <int> GetWindow(DateTime startDate, DateTime endDate, DataSeries <Bar> s) { var sList = s.ToList(); var start = sList.FindIndex(x => x.Timestamp.Date >= startDate.Date); var end = sList.FindLastIndex(x => x.Timestamp.Date <= endDate.Date); return(new Tuple2 <int>(start, end)); }