what is the {start time} for {Tilda Swinton} has {partner} as {John Byrne} ?
what is the {begin time} for {Tilda Swinton} which has {accomplice} as {John Byrne} ?
what is the {start time} for {Tilda Swinton} which has {partner} as {John Byrne} ?
SELECT ?k WHERE { ?l property:unmarried_partner resource:John_Byrne . resource:Tilda_Swinton property:unmarried_partner ?l . ?l property:start_time ?k }
select distinct ?value  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q200534> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P451> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <http://wikidata.dbpedia.org/resource/Q6224236> .
?statement <http://www.wikidata.org/entity/P580> ?value. 
} 

SELECT ?value WHERE { wd:Q200534 p:P451 ?s . ?s ps:P451 wd:Q6224236 . ?s pq:P580 ?value}