Re: [office] YEARFRAC information

["David A. Wheeler" <dwheeler@dwheeler.com>]

I said:
> I've published detailed information on YEARFRAC, including
> a detailed definition that matches what Excel _actually_ does
> instead of what OOXML says (they are incompatible)...
> We now need to decide what to do with OpenFormula; this affects
> 26 functions.  The 'obvious' answer is to use the definitions that
> are actually compatible with Excel, since there are far more Excel
> .docx spreadsheets than OOXML spreadsheets
> (to my knowledge, there are no OOXML spreadsheet documents).
> We could assign basis values 16..31 as meaning "the same as
> OOXML basis 0..15"; I think we can appeal to the definition of an
> external specification if it's a standard :-). I suggest these
> be optional.

Andreas J Guelzow _basically_ agreed, saying:
> I think we should clearly use the definitions that are actually
> compatible with Excel (and use the same base numbers as Excel). 
> I also think that we are already assigning basis values 16 to 31 to the
> algorithms currently given in OOXML, but make their implementation
> optional. (I do not think we should refer to the external specification
> since implementation of OpenFormula compatible programs should not
> depend on possible change in such an external specification.) Since
> OOXML has been approved as a standard I think it is reasonable to assume
> that the current OOXML is final (and that any future changes in that
> specification does not conflict with the current specs.)

Unless there is an objection soon, I intend to embed the YEARFRAC/Basis definitions
into the formula spec, in the way described above.  We really need to specify
the basis values for interoperability, and this seems like a reasonable way to do it.

--- David A. Wheeler