bug#64972: bibtex-autokey-get-year does not recognize biblatex date ranges

[Eli Zaretskii]

> From: Gustavo Barros <gusbrs.2016@gmail.com>
> Date: Mon, 31 Jul 2023 09:53:41 -0300
> 
> Hi All,
> 
> I think this counts more as a feature request than a bug report.  But,
> currently, `bibtex.el's `bibtex-autokey-get-year' cannot handle
> `biblatex' date ranges, and it would be nice if it did.
> 
> For example, calling `M-: (bibtex-autokey-get-year)' with point inside
> the entry:
> 
>     @Article{,
>       author       = {Author, J.},
>       title        = {Title},
>       journaltitle = {Journal},
>       date         = {2020-10/2020-12},
>     }
> 
> Results in user-error "Year or date field ‘2020-10/2020-12’ invalid".
> 
> The "date" field, however, is valid `biblatex' syntax for a date
> range, according to the section "2.3.8 Date and Time Specifications"
> of `biblatex's manual.

Roland, any comments?

Thanks.