As Ed suggests, seasons are complicated. And during the previous phase of
this work they proved to be too complicated to solve completely. However
there is a stub in the spec for a "season qualifier":
"When season is immediately followed by '^' then a qualifier follows the ^.
However, this specification does not define a vocabulary for seasonal
qualifiers (the example above is hypothetical). Communities are encouraged
to develop seasonal vocabularies. There is further discussion of this in
Annex A discusses possible future features, including the "season qualifier"
No seasonal qualifiers have yet been developed. 21, 22, 23, 24 are used to
mean Spring, Summer, Autumn, Winter, respectively, in place of month, for
example, '2001-21' for Spring, 2001. When the season is immediately followed
by '^' then a qualifier follows the ^. For example, in the expression
'2001-21^xxx, "xxx" is the qualifier. But no such qualifiers have been
A qualifier might indicate hemisphere - north or south. There are also
competing semantics for seasonal names: Meteorological, Astronomical,
Cultural, Historical... For example, on February 1 it is Spring in Ireland
but Winter in England (where March 1 traditionally marks the start of
Spring). Universities have varying semantics: At the University of
California, for example, Spring starts on March 28. Some campuses on the
semester system use Fall and Spring to denote the two semesters but others
use Winter and Summer (common in Germany).
There is also the possibility of inserting a geographic qualifier. And there
is discussion about interpreting 21, 22, 23, 24 as quarter rather than
season, and also distinguishing calendar from fiscal quarter."
> -----Original Message-----
> From: Discussion of the Developing Date/Time Standards
> [mailto:[log in to unmask]] On Behalf Of Edward C. Zimmermann
> Sent: Tuesday, September 11, 2012 7:48 AM
> To: [log in to unmask]
> Subject: Re: [DATETIME] Minor comments on Draft Submission 13 January 2012
> On Tue, 11 Sep 2012 07:03:02 -0400, Rintze Zelle wrote
> > On Tue, Sep 11, 2012 at 4:42 AM, [UTF-8?]SaaÅ¡ha Metsärantala
> <[log in to unmask]> wrote:
> > > Dates in square brackets may contain seasons and (and as we made
> > > clear
> > > year) seasons within the same year cannot be sorted.
> > That's not what the spec suggests right now: "Seasons should sort as
> > Spring < Summer < Autumn < Winter"
> Seasons do sort--- Winter comes after Autumn/Fall and is followed by
> and between Spring and Autumn is Summer--- BUT not in the (ISO) year and
> that is the problem.
> Summer 1988, for example, in the Southern Hemisphere is followed by Autumn
> 1989. Winter 1988 too is before Summer 1988 there. That is also why we
> discussed last year the addition of geo-predicates--- not only is this
> critical to a global sort but we also have issues of which season we are
> speaking of (the terms even in the same hemisphere can refer to different
> date intervals).
> Even with geo information we would still need to profile sorts just as we
> do for place names in other applications---- in the German language, for
> example, there are a number of alphanumeric sorts widely used in
> telephone books etc. and they are quite different from a numerical value
> sort driven by numerical character value in Unicode (Ray will recall my
> objections and issues on sorting in The Hague).
> > > Of course, we could decide to sort dates within square brackets if
> > > none of them contains any season (for example), but I do not
> > > consider this a
> > Okay, so sorting the dates within square brackets seems to be
> > impossible when there are dates with seasons around. I still would
> > like the specification to be clear about how to interpret examples
> > like the following, though:
> > ---
> > A) [1760-12, 1760-01..]
> > Should this be read as
> > 1) "January or December 1760, or some later month"
> > or
> > 2 )"December 1760, or some month after January 1760" ?
> > The second explanation is strange, since December 1760 is part of the
> > open range after January 1760. But if you agree that it should be the
> > first explanation, then you are implicitly sorting by date (and then
> > I'd argue that the specification shouldn't rely on implicit
> > assumptions by the reader).
> > ---
> > B) [1760-21..]
> > "Spring of 1760 or a later season"
> > or
> > "Spring of 1760 or a later year"?
> > ---
> > C) [1760-06, 1760-21..]
> > "June of 1760 or a later year"?
> > ---
> > D) [1760, 1760-2]
> > "February of 1760 or later"
> > or
> > "1760 or later"?
> > The specification currently reads: "this specification does not
> > address the sort order, that is, whether (for example) 2000 is before
> > or after 2000-01, 2000-10, 2000-12, 2000-21, etc."
> > ---
> > I think the specification should either be clear about how to
> > interpret the above examples, or simple do not allow them. If the
> > specification stays as it is on the topic of sorting, the only way to
> > use square brackets unambiguously seems to:
> > a) disallow the joined use of year-season dates and the double-dot
> > b) require that all dates are of the same precision when the
> > double-dot is
> > With these two requirements, it becomes possible to unambiguously sort
> > dates within square brackets and have the double-dot target the last
> > and most recent date.
> > Rintze
> Edward C. Zimmermann, NONMONOTONIC LAB/BSn http://www.ibu.de/IB_Engine
> Umsatz-St-ID: DE130492967