Re: Encoding an incomplete date as xsd:dateTime

Hi Heiko,
On 10 Feb 2014, at 15:55, 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?
Safe as in nothing will explode, then yes.
Safe as in every single piece of software aimed at reading vcard will understand this triple and not crash, then no.

If you are in an owl world then instead of using a xsd:gYear you should probably use restriction classes to model the born in a certain year 
but not sure when in the year.

Not being an OWL person, I would think it look something like this.

_:me a vcard:Individual;
rdf:subClassOf [owl:Restriction owl:onProperty vcard:BDAY ;
                owl:allValuesFrom [xsd:minInclusive “1983-01-00”^^xsd:dateTime , xsd:maxInclusive “1984-01-00”^^xsd:dateTime ]

The benefit here is that using restrictions allow you talk about what you do know. e.g. when talking about a historic person you can add notes to such a date range.
The time ontology is a good starting point for describing these things better. But are most likely beyond the use case of vcard. 

Most OWL reasoners will not take into account xsd:gYear and xsd:gYearMonth. 

Another approach is to mint new properties e.g. my_vcard:birthYear a owl:dataTypeProperty .

Regards,
Jerven
> 
> 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 15:11:23 UTC