Power Bi,Power Query - Variable for: errors/production time

Hello, Sebatian 

let
    events_table = your_events_table,
    interval_table = your_intervals_table,
    event = #table(
        {"type", "value"}, 
        {
            {"event", events_table[Date_time_event]}, 
            {"start", interval_table[IntervalStart]},
            {"end", interval_table[IntervalEnd]}
        }
    ),
    expand = Table.ExpandListColumn(event, "value"),
    sort = Table.Sort(expand,{{"value", Order.Ascending}}),
    g = Table.Group(
        sort, "type", 
        {{"events", (x) => List.Count(List.Select(x[type], (w) => w = "event"))}, {"date", (x) => Date.From(x{0}[value])}}, 
        GroupKind.Local, 
        (s, c) => Number.From(List.Contains({"start", "end"}, c))),
    filter_start = Table.SelectRows(g, each ([type] = "start")),
    g2 = Table.Group(filter_start, {"date"}, {{"events", each List.Sum([events]), type number}})
in
    g2