On Mon, Aug 10, 2020 at 09:12:27AM +0200, claude fuhrer wrote: > Hi everybody > > It seems that I don't understand how to compute the week number in emacs. There's no such thing as "the week number in emacs". Or... there are at least three. Cribbed from the docs (C-h i format-time-string): "%U is the week number starting on Sunday, %W starting on Monday, %V according to ISO 8601." The thing is there are many meaningful ways to define such a thing as a "week number", and several of them are in current use. See, e.g. [1] for even more fun :-) Once you know what kind of results you want, the rest tends to be easier. Of course, some people pick "whatever Excel does". Don't do that ;) Cheers [1] https://en.wikipedia.org/wiki/Week_number#Week_numbering - t