I think there is an error in SqlServerMonitoringApi.GetHourlyTimelineStats. If you look at this code snippet
var result = new Dictionary<DateTime, long>();
for (var i = 0; i < dates.Count; i++)
var value = valuesMap[valuesMap.Keys.ElementAt(i)];
you will see that the row with “result.Add(dates[i], value);” add wrong data. The date combined with the value is wrong.
I hope I was clear.