Imke Feldmann translates another Excel function:
If you are looking for the Excel equivalent of the WEEKNUM function for Power Query this article is for you.
As this is also a function that has many regional options, I was lucky to find an algorithm that I could use for its main part here: M functions to convert between ISO 8601 Week & Year ⇄ dates (e.g.,
2014-12-29⇄"2015-W01-1") (github.com)
Read on for the code and details on function parameters.