Re: Open intervals for temporalCoverage ?

2016-09-14 12:49 GMT+02:00 Dan Brickley <danbri@google.com>:

> 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/)"""
>

That kind of syntax would be perfect and doesn't break the general ISO 8601
syntax.
I have created an issue at
https://github.com/schemaorg/schemaorg/issues/1365

Cheers


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