private void LoadStories() { var repo = new HistoryRepository(); List <History> data = repo.AllAsync(); if (data != null && data.Count() > 0) { AddFirstValue(ref data); var summaryWorking = from h in data where h.IsWorking == true group h by h.End.Date into g select new GroupValue { Category = g.Key.Date, Value = g.Sum(x => x.Durations) }; var summaryBreaks = from h in data where h.IsWorking == false group h by h.End.Date into g select new GroupValue { Category = g.Key.Date, Value = g.Sum(x => x.Durations) }; Workings.AddRange(summaryWorking); Breaks.AddRange(summaryBreaks); } else { var today = new List <GroupValue>() { new GroupValue() { Category = DateTime.Now.Date, Value = 0 } }; Workings.AddRange(today); Breaks.AddRange(today); } }