grace:has_time_span

@prefix grace: <https://w3id.org/grace/ontology/> .
@prefix owl: <http://www.w3.org/2002/07/owl#> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .

grace:has_time_span a owl:ObjectProperty ;
    rdfs:label "has time span"@en ;
    rdfs:comment "what happened at this date?" ;
    rdfs:domain [ a owl:Class ;
            owl:unionOf ( grace:event grace:object ) ] ;
    rdfs:range grace:date ;
    rdfs:subPropertyOf grace:date_object .