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Re: Open intervals for temporalCoverage ?

From: Richard Wallis <richard.wallis@dataliberate.com>
Date: Wed, 14 Sep 2016 11:55:55 +0100
Message-ID: <CAD47Kz4nJ5VRTYx3Abz66WBmqhHzaWdAvs7KvaeokcYzJWPzxQ@mail.gmail.com>
To: Dan Brickley <danbri@google.com>
Cc: Thomas Francart <thomas.francart@sparna.fr>, "schema.org Mailing List" <public-schemaorg@w3.org>
No obvious sign of evolution at ISO.

It looks like RKMS are following the same lines as Dublin Core  “*The RKMS
Extension to ISO 8601 allows open date ranges*”.

We could potentially document a Schema equivalent, or say we would
recommend recognition of one of these extensions to ISO 8601?

Not sure how open to lobbying the ISO folks would be, and if they are how
fast they would react.

~Richard.

Richard Wallis
Founder, Data Liberate
http://dataliberate.com
Linkedin: http://www.linkedin.com/in/richardwallis
Twitter: @rjw

On 14 September 2016 at 11:49, Dan Brickley <danbri@google.com> wrote:

> On 14 September 2016 at 11:14, Richard Wallis
> <richard.wallis@dataliberate.com> wrote:
> > As the documentation for temporalCoverage states, it expects ISO 8601
> time
> > interval format, so the question lies there.
> >
> > Your understanding I believe is correct, that the current version of the
> > standard ( ISO 8601:2000 ) does not support open ended time intervals.
> >
> > In Dublin Core, which bases its formats on ISO 8601,  open ended
> intervals
> > are supported but explicitly state “This representation of an open date
> > range is not compatible with the representation of a time-interval
> defined
> > by ISO8601:2000.”
> >
> > This has been the subject of a short
> > https://github.com/project-open-data/project-open-data.
> github.io/issues/415.
> > I support their conclusion that an open ended time period would be
> currently
> > best represented by the appropriate use [or non-use] of schema:startDate
> and
> > schema:endDate.
>
> The DC specs were done a while ago - is there any chance ISO 8601 has
> evolved since then? open-ended seems a reasonable requirement, so long
> as it doesn't make the syntax ambiguous.
>
> I looked around for others hitting this situation and found at least
> http://www.lyberty.com/meta/iso_8601.htm ... there may be more out
> there along similar lines:
>
> """
>
> Open Date Ranges
>
> Some record-keeping metadata requires specification of date ranges.
> For example, a Business Activity may only have been valid between the
> years 1949 and 1953. ISO 8601 allows the specification of date ranges
> using a forward slash (/) to separate dates representing the start and
> end of the range. For example, "1949/1953". Recordkeeping metadata
> also requires specification of open date ranges. For example, an
> Agency may have an operational period from July 1st 1998 until the
> present date. Open date ranges such as this are not defined in ISO
> 8601. The RKMS Extension to ISO 8601 allows open date ranges to be
> specified by extending the ISO 8601 syntax to allow the omission of
> either the start or end date in the range. Acceptable RKMS date ranges
> are then:
>
> Closed date range: DateTime/DateTime (e.g. 1949/1953-01-01)
> Date range with unknown start: /DateTime (e.g. /2000-12-31T11:59:59)
> Date range with no end date: DateTime/ (e.g. 1998-07-01/)"""
>
> Dan
>
Received on Wednesday, 14 September 2016 10:56:27 UTC

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