rdf - In an ontology, how to define a property's value as a datetime -
when writing ontology , want create class , property relating time/date, assume you'll have structurally (psuedo code):
class:project label: project property:duedate label: expected completion time , date of project domain: project range: datetime (?) i've googled around , found owl-time ontology, use case confusing me because looks i'm supposed define quite few things. on right track here?
you haven't mentioned how you're constructing ontology. if you're writing owl hand (e.g., functional syntax), you'd 1 way; if you're writing rdf, you'll (you'd write rdf encoding of owl axiom). easiest way see how these done defining ontology using protégé, or similar graphical editor, , @ resulting code. assume since used term datetime, you're @ data property values should literals of datatype xsd:datetime.
in protégé
in protégé you'd this:
in owl functional syntax
the syntax data property range axioms given in 9.3.5 data property range owl 2 web ontology language structural specification , functional-style syntax (second edition). when save ontology in functional syntax, this:
prefix(xsd:=<http://www.w3.org/2001/xmlschema#>) prefix(owl:=<http://www.w3.org/2002/07/owl#>) prefix(xml:=<http://www.w3.org/xml/1998/namespace>) prefix(rdf:=<http://www.w3.org/1999/02/22-rdf-syntax-ns#>) prefix(rdfs:=<http://www.w3.org/2000/01/rdf-schema#>) ontology(<http://stackoverflow.com/q/21486301/1281433/projects> declaration(class(<http://stackoverflow.com/q/21486301/1281433/projects#project>)) declaration(dataproperty(<http://stackoverflow.com/q/21486301/1281433/projects#duedate>)) datapropertydomain(<http://stackoverflow.com/q/21486301/1281433/projects#duedate> <http://stackoverflow.com/q/21486301/1281433/projects#project>) datapropertyrange(<http://stackoverflow.com/q/21486301/1281433/projects#duedate> xsd:datetime) ) the important axiom
datapropertyrange(<http://stackoverflow.com/q/21486301/1281433/projects#duedate> xsd:datetime) in rdf
owl can serialized in rdf, , rdf can serialized in number of ways. here's ontology looks in turtle serialization of rdf, , in rdf/xml serialization:
@prefix : <http://stackoverflow.com/q/21486301/1281433/projects#> . @prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> . @prefix owl: <http://www.w3.org/2002/07/owl#> . @prefix xsd: <http://www.w3.org/2001/xmlschema#> . @prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> . <http://stackoverflow.com/q/21486301/1281433/projects> owl:ontology . :project owl:class . :duedate owl:datatypeproperty ; rdfs:domain :project ; rdfs:range xsd:datetime . the important triple, of course,
:duedate rdfs:range xsd:datetime <rdf:rdf xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns="http://stackoverflow.com/q/21486301/1281433/projects#" xmlns:owl="http://www.w3.org/2002/07/owl#" xmlns:xsd="http://www.w3.org/2001/xmlschema#" xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"> <owl:ontology rdf:about="http://stackoverflow.com/q/21486301/1281433/projects"/> <owl:class rdf:about="http://stackoverflow.com/q/21486301/1281433/projects#project"/> <owl:datatypeproperty rdf:about="http://stackoverflow.com/q/21486301/1281433/projects#duedate"> <rdfs:domain rdf:resource="http://stackoverflow.com/q/21486301/1281433/projects#project"/> <rdfs:range rdf:resource="http://www.w3.org/2001/xmlschema#datetime"/> </owl:datatypeproperty> </rdf:rdf> it's still same triple that's important here, in format it's written as:
<owl:datatypeproperty rdf:about="http://stackoverflow.com/q/21486301/1281433/projects#duedate"> <rdfs:range rdf:resource="http://www.w3.org/2001/xmlschema#datetime"/> </owl:datatypeproperty> 
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