var event2 = (
from e in Tb_Events
where e.EventID == 10010
group e by new { e.EventID } into menge
select new { menge.Key.EventID,dtStart = menge.Min(m => m.TimeGenerated),dtEnd = menge.Max(m=>m.TimeGenerated) }
);


var Total = (from e in Tb_Events
where e.EventID == 10010
group e by new {e.EventID,e.TimeGenerated.Value.Year,e.TimeGenerated.Value.Month} into gesamt
select new {jahr = gesamt.Key.Year,monat = gesamt.Key.Month, total = gesamt.Count()});

//Total.Dump();


var kal = (from c in Calendars
group c by new {c.Year,c.Month} into dates
orderby dates.Key.Year,dates.Key.Month
select new {dates.Key.Year,dates.Key.Month});

(from k in kal
//join t in Total on new { k.Year,k.Month} equals new {t.jahr,t.monat}
join t in Total on new {k.Year} equals new {t.jahr}
select k).Dump();
//from t in t2.DefaultIfEmpty()
//select new {
//  t.jahr,
//  t.monat,
//  Total = t == null ? 0 : t.total
//}).Dump();