Eike:
> I just thought of the possibility that Excel might follow the idea of
> enhancing the WEEKNUM functionality, but use a different numbering in
> the parameters. Currently it generates a #NUM! error for values other
> than 1 or 2 as the second argument, but in that case documents exported
> to Excel would silently calculate different results. But maybe I'm too
> precautious.
That's a valid concern. Of course, that can be implemented as COM.MICROSOFT.WEEKNUM at that time, and eventually become a WEEKNUM_E or whatever.
> > We can do much better, of course; we can implement a good WEEKNUM (with at least 0..7) and an ISOWEEKNUM so that the users can get whatever they need to get.
>
> With the minimum-number-of-days parameter we could also drop ISOWEEKNUM,
> since it could be written as WEEKNUM(d;2;4). Do we want that?
No, I think we want an ISOWEEKNUM as well. There are already several implementations that _have_ an ISOWEEKNUM. And in any case, it makes sense to have a function that makes it REALLY easy to access the ISO week number.
--- David A. Wheeler