W3C Time ontology
Most SAREF extensions use W3C Time ontology, sometimes differently.
It may be imported at the level of SAREF Core directly
SAREF4WATR uses the W3C Time ontology. It copies the definition of time:DayOWeek, time:Instant, time:Interval, time:TemporalEntity, and time:TemporalDuration, and several properties. Other SAREF ontologies use these concepts, therefore it could be useful to define them at the level of SAREF Core. SAREF4WATR use these concepts in ranges of some properties that apply to the class s4watr:Tariff, which may be interesting to promote to SAREF Core.
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Proposal:
SAREF Extensions should not promote the use of the W3C Time Ontology for time units over other ontologies of units of measure.
In SAREF Extensions, declare the concepts from W3C Time ontology that are needed, for example:
time:TemporalUnit a owl:Class ; rdfs:isDefinedBy time: . time:TemporalEntity a owl:Class ; rdfs:isDefinedBy time: .
SAREF Extensions should only declare the concepts that they use.
Favour xsd:dateTime and xsd:duration if modeling with DPs could be enough. Especially if only instants are expected.