Re: Encoding an incomplete date as xsd:dateTime

Hi all

Are you aware of the Library of Congress Extended Date/Time Format (EDTF)?
There was an interesting presentation at DC 2013 about its implementation
in real world
http://dcevents.dublincore.org/IntConf/dc-2013/paper/view/183

Bernard


2014-06-25 16:00 GMT+02:00 Paul Houle <ontology2@gmail.com>:

> I've been thinking about date representations a lot lately.  Even if
> you're going to cobble something together out of the various XSD
> types,  it still helps to have a theory.
>
> A better underlying data type for dates is a time interval or set of
> time intervals.
>
> This represents the fact that many "events" happen over a time
> interval (such as a meeting or movie show time),  that we often only
> know a year or a day,  that things are measured on idiosyncratic time
> basis such as the fiscal years of various organizations,  that there
> are both practical and theoretical limits on both the precision and
> accuracy of time measurements.
>
> Intervals have their charms,  but if you include interval sets you can
> also represent concepts such as "Monday", "June 25" and "the third
> Tuesday of the month".
>
> Of course,  it creates trouble that there is no total ordering over
> intervals/interval sets,  but that's a fundamental problem to any
> flexible time representation.
> ᐧ
>
> On Mon, Feb 10, 2014 at 9:37 AM, Heiko Paulheim
> <heiko@informatik.uni-mannheim.de> wrote:
> > Hi all,
> >
> > xsd:dateTime and xsd:date are used frequently for encoding dates in RDF,
> > e.g., for birthdays in the vcard ontology [1]. Is there any best
> practice to
> > encode incomplete date information, e.g., if only the birth *year* of a
> > person is known?
> >
> > As far as I can see, the XSD spec enforces the provision of all date
> > components [2], but "1997-01-01" seems like a semantically wrong way of
> > expressing that someone is born in 1997, but the author does not know
> > exactly when.
> >
> > Thanks,
> > Heiko
> >
> > [1] http://www.w3.org/2006/vcard/ns
> > [2] http://www.w3.org/TR/xmlschema-2/#dateTime
> > [3] http://www.w3.org/TR/xmlschema-2/#date
> >
> > --
> > Dr. Heiko Paulheim
> > Research Group Data and Web Science
> > University of Mannheim
> > Phone: +49 621 181 2646
> > B6, 26, Room C1.08
> > D-68159 Mannheim
> >
> > Mail: heiko@informatik.uni-mannheim.de
> > Web: www.heikopaulheim.com
> >
> >
>
>
>
> --
> Paul Houle
> Expert on Freebase, DBpedia, Hadoop and RDF
> (607) 539 6254    paul.houle on Skype   ontology2@gmail.com
>
>


-- 

*Bernard Vatant*
Vocabularies & Data Engineering
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