Automate Duplicate data sets in Power Query

Hi, jcru1999 

According to your description, your data comes from a URL, and you need to modify the fixed parameters of the URL every time you get the data.
If you want to automate, I think you can define the way you get the data in Power Query as a custom function.

The parameter passed in is your date, and then you create a date column at the end of the month.

The end of month's date column you can use this M code(put this in the "Advanced Editor"):

let
    Source = List.Distinct(List.Transform(List.Dates(#date(2023,1,1), Duration.Days(Duration.From(#date(2023,12,31)-#date(2023,1,1))) +1, #duration(1, 0, 0, 0))
,(x)=> Date.EndOfMonth(x))),
    #"Converted to Table" = Table.FromList(Source, Splitter.SplitByNothing(), null, null, ExtraValues.Error),
    #"Changed Type" = Table.TransformColumnTypes(#"Converted to Table",{{"Column1", type date}})
in
    #"Changed Type"

Then you can use "Add custom column."
And pass in this [Column1] column to call the Custom Column you wrote to return your data row by row.

For more information, you can refer to this:
How to use Power Query Custom Functions (exceloffthegrid.com)

Thank you for your time and sharing, and thank you for your support and understanding of PowerBI! 

Best Regards,

Aniya Zhang

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