Skipping overlapping date & get date difference.

Hello abdsk ,
this can be achieved by the magical 5th parameter in the Table.Group-function.
If you paste the following M-code into the advanced editor of a blank query, you can follow the steps along:

let
  Source = Table.FromRows(
    Json.Document(
      Binary.Decompress(
        Binary.FromText(
          "i45W8k1MzsjMS1XSUTI00jcw1TcyMDJWMDCyMjAAIlRRQwMrY7BorA4ufZZQFaj6zKCm4dRnaI7NPiMD7PqMkV0E12egb2AGdQV2fQYmCBXGCH3GcFG4abGxAA==",
          BinaryEncoding.Base64
        ),
        Compression.Deflate
      )
    ),
    let
      _t = ((type nullable text) meta [Serialized.Text = true])
    in
      type table [Equipment = _t, #"Start Time" = _t, #"End Time" = _t]
  ),
  #"Changed Type" = Table.TransformColumnTypes(
    Source,
    {{"Start Time", type datetime}, {"End Time", type datetime}}
  ),
  #"Grouped Rows" = Table.Group(
    #"Changed Type",
    {"Equipment", "Start Time", "End Time"},
    {
      {"Count", each _},
      {"MinStart", each List.Min([Start Time]), type nullable datetime},
      {"MaxEnd", each List.Max([End Time]), type nullable datetime}
    },
    GroupKind.Local,
    (x, y) => Number.From(x[End Time] < y[Start Time])
  ),
  #"Inserted Time Subtraction" = Table.AddColumn(
    #"Grouped Rows",
    "Duration",
    each Duration.TotalHours([MaxEnd] - [MinStart])
  )
in
  #"Inserted Time Subtraction"

Hi abdsk ,
unfortunately this is not so easy any more, as it has a different logic than I originally thought.
Please use this code instead:

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("xdNBDsIwDATAr6Ccg+S4LbS8BKj6/2/UvsGu1hInpJyckRPbyb635+vderNxjeXmfjF7mGXoBqGjV3r5SU9ab6THXerBuSuNx9YaS6o1bpXajbTPWjtrPR3nKnM6LjQeG6FV58Zje5uwlA/NPcnHoG7Ck883KDRtRb9N65W1a72R9v9oKilCs9aYKEK6g/kbUGObvn8D3pv6fZw=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Equipment = _t, #"Start Time" = _t, #"End Time" = _t]),
ChangedType = Table.TransformColumnTypes(
    Source, 
    {{"Equipment", type text}, {"Start Time", type datetime}, {"End Time", type datetime}}
  ), 
  #"Grouped Rows" = Table.Group(
    ChangedType, 
    {"Equipment"}, 
    {
      {
        "Result", 
        each 
          let
            InputTable = Table.Buffer(Table.SelectColumns(_, {"Start Time", "End Time"})), 
            Custom1 = List.Generate(
              () => [
                MinStart = InputTable{0}[Start Time], 
                MaxEnd   = InputTable{0}[End Time], 
                Group    = 1, 
                Counter  = 0
              ], 
              each [Counter] <= Table.RowCount(InputTable), 
              each [
                CurrentStart = InputTable{[Counter]}[Start Time], 
                CurrentEnd = InputTable{[Counter]}[End Time], 
                GroupChange = CurrentStart > [MaxEnd] and CurrentEnd > [MinStart], 
                MinStart = 
                  if GroupChange then
                    CurrentStart
                  else
                    List.Min({CurrentStart, [MinStart]}), 
                MaxEnd = if GroupChange then CurrentEnd else List.Max({CurrentEnd, [MaxEnd]}), 
                Group = if GroupChange then [Group] + 1 else [Group], 
                Counter = [Counter] + 1
              ]
            ), 
            #"Converted to Table" = Table.FromList(
              Custom1, 
              Splitter.SplitByNothing(), 
              null, 
              null, 
              ExtraValues.Error
            ), 
            #"Expanded Column1" = Table.ExpandRecordColumn(
              #"Converted to Table", 
              "Column1", 
              {"MinStart", "MaxEnd", "Group"}
            ), 
            #"Grouped Rows" = Table.Group(
              #"Expanded Column1", 
              {"Group"}, 
              {
                {"MinStart", each List.Min([MinStart]), type datetime}, 
                {"MaxEnd", each List.Max([MaxEnd]), type datetime}
              }
            )
          in
            #"Grouped Rows"
      }
    }
  ), 
  #"Expanded Result" = Table.ExpandTableColumn(
    #"Grouped Rows", 
    "Result", 
    {"MinStart", "MaxEnd"}
  )
in
  #"Expanded Result"