[m-rev.] for review: improve the documentation of the calendar module

[Julien Fischer]

On Tue, 17 Mar 2026 at 17:54, Zoltan Somogyi <zoltan.somogyi at runbox.com> wrote:
>
>
> On Tue, 17 Mar 2026 16:22:17 +1100, Julien Fischer <jfischer at opturion.com> wrote:
> > > > > +    % The year must have at least four digits; years with more than four digits
> > > > > +    % are accepted. The microseconds component (.mmmmmm) is optional. If
> > > > > +    % present, it may have between one and six digits.
> > > > > +    %
> > > > > +    % Fail if the string does not conform to the above format, or if any
> > > > > +    % date or time component is outside its valid range.
> > > >
> > > > What is the justification for restricting to 4+ digit years?
> > >
> > > Good question. The short answer is I don't know.
> > > I intend to investigate further and lift the restriction if I can't
> > > find a reason.
>
> I wasn't arguing for dropping the restriction; I was arguing for
> documenting the reason for it.
>
> > Requiring that years have at least four digits in date-time
> > representations comes
> > from ISO 8601-1.  Other time-related standards have picked it up. For
> > example, both RFC 3339 and the XML Schema standard on which this
> > module was based.
>
> Using that info, I wrote (and just committed) this diff. For your review.

You didn't attach the diff, so I went and took a look on github.

That's fine.

Julien.