gtfs:start_date leaf node

@prefix gtfs: <http://ontology.gtfs.org/reference#> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .

gtfs:start_date a rdf:Property ;
    rdfs:label "start_date"@en,
        "fecha_inicio"@es,
        "data_inicio"@pt ;
    rdfs:comment "Start date for the service."@en,
        "Fecha de inicio del servicio."@es,
        "Data de início do serviço."@pt ;
    rdfs:domain gtfs:Calendar ;
    rdfs:range xsd:string .