W3C home > Mailing lists > Public > semantic-web@w3.org > February 2014

Re: Encoding an incomplete date as xsd:dateTime

From: Niklas Lindström <lindstream@gmail.com>
Date: Mon, 10 Feb 2014 16:53:07 +0100
Message-ID: <CADjV5jdUA0nOHvcSndPHkCWYRXgcPLD1wuv9RYekReEQZvYv0Q@mail.gmail.com>
To: Heiko Paulheim <heiko@informatik.uni-mannheim.de>
Cc: Jerven Bolleman <me@jerven.eu>, Semantic Web <semantic-web@w3.org>, "public-lod@w3.org community" <public-lod@w3.org>, Bernd Opitz <opitz.bernd@gmail.com>
Hi Heiko,

Unless you want to use another ontology (e.g. BIO [1][2] or
schema.org[3]), I'd probably go ahead and break that contract,
although it is not
technically safe (AFAIK, it's a violation of OWL semantics). It depends on
the expected consumption of your data.

I would say that the vcard ontology formally needs to be fixed to allow for
more variation. It actually seems to have been amended somewhat in 2010
[4], to at least not require the exact second (or fraction thereof) of the
birth. But that's hardly enough. A lot of the point of datatyped literals
in RDF is lost when datatype properties are locked down like this.

Cheers,
Niklas

[1]: http://vocab.org/bio/0.1/.html
[2]: http://wiki.foaf-project.org/w/BirthdayIssue
[3]: http://schema.org/birthDate
[4]: http://www.w3.org/Submission/2010/SUBM-vcard-rdf-20100120/




On Mon, Feb 10, 2014 at 3:55 PM, Heiko Paulheim <
heiko@informatik.uni-mannheim.de> wrote:

> Hi Jerven,
>
> this looks like a pragmatic solution. But I wonder if it may lead to any
> conflicts, e.g., the vcard ontology defines the bday property with
> xsd:dateTime as its range explicitly. Is it "safe" to simply use an
> xsd:gYear value as its object?
>
> Best,
> Heiko
>
>
>
> Am 10.02.2014 15:43, schrieb Jerven Bolleman:
>
>  Hi Heiko,
>>
>> http://www.w3.org/TR/xmlschema-2/#gYear and http://www.w3.org/TR/
>> xmlschema-2/#gYeargYearMonth
>> are the datatypes that you should use.
>>
>> Regards,
>> Jerven
>>
>> On 10 Feb 2014, at 15:37, 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
>>>
>>>
>>>
>>
>>
> --
> 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
>
>
>
Received on Monday, 10 February 2014 15:54:10 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 1 March 2016 07:42:48 UTC