Overlapping Time Series Data in Power Query - excel

Question

Hello all you power query wizards,
I have a similar question to this question: Timeseries with overlapping timeframes, using just the most recent in Excel Power Query, except my column isn't just a date column, but instead a date/time column. I am bringing together a directory of files that look like this and have overlapping times but I only want to keep the newer data instead of combining them together:
List A
List B
Does anyone have a strategy to accomplish this goal or is this something I should do outside of Power Query, such as python?
Many thanks in advance for any insight you can provide!
let
Source = Folder.Files("C:\Users\xxxx\OneDrive\Documents\Atom Projects\10MinOrtho\2. Orthometric\2021-06\10MinOrthos"),
#"Filtered Hidden Files1" = Table.SelectRows(Source, each [Attributes]?[Hidden]? <> true),
#"Invoke Custom Function1" = Table.AddColumn(#"Filtered Hidden Files1", "Transform File (2)", each #"Transform File (2)"([Content])),
#"Renamed Columns1" = Table.RenameColumns(#"Invoke Custom Function1", {"Name", "Source.Name"}),
#"Removed Other Columns1" = Table.SelectColumns(#"Renamed Columns1", {"Source.Name", "Transform File (2)"}),
#"Expanded Table Column1" = Table.ExpandTableColumn(#"Removed Other Columns1", "Transform File (2)", Table.ColumnNames(#"Transform File (2)"(#"Sample File (2)"))),
#"Changed Type" = Table.TransformColumnTypes(#"Expanded Table Column1",{{"Source.Name", type text}, {"Column1", type date}, {"Column2", type time}, {"Column3", type number}}),
#"Removed Columns" = Table.RemoveColumns(#"Changed Type",{"Source.Name"}),
#"Merged Date and Time" = Table.CombineColumns(#"Removed Columns", {"Column1", "Column2"}, (columns) => List.First(columns) & List.Last(columns), "Merged"),
#"Sorted Rows" = Table.Sort(#"Merged Date and Time",{{"Merged", Order.Ascending}})
in
#"Sorted Rows"

Answer 1

You don't describe exactly what you want to do with the overlapped times.
I suggest
remove the entries from List A that are in the overlap region with List B.
This can be done with a simple filter based on the first time listed in List B
I have assumed that List B is in date/time sorted order. If not a minor code change will be required
Then append the two lists
M Code
let
Source = Excel.CurrentWorkbook(){[Name="ListA"]}[Content],
#"Changed Type" = Table.TransformColumnTypes(Source,{{"Date/Time", type datetime}, {"Value", type number}}),
Source2 = Excel.CurrentWorkbook(){[Name="ListB"]}[Content],
#"Changed Type2" = Table.TransformColumnTypes(Source2,{{"Date/Time", type datetime}, {"Value", type number}}),
//overlap starts at the first date from the second list
overlapStart = #"Changed Type2"[#"Date/Time"]{0},
//Filter list A to end before start time in List B
filteredA = Table.SelectRows(#"Changed Type", each [#"Date/Time"] < overlapStart),
//now combine the two lists
combLists = Table.Combine({filteredA,#"Changed Type2"})
in
combLists
Lists A & B
Combined