what is the {start time} for {Gloria Swanson} has {spouse} as {Wallace Beery} ?
When Gloria Swanson began as the wife of Wallace Beery?
When Gloria Swanson started as the spouse of Wallace Beery?
SELECT ?x WHERE { ?b property:spouse resource:Wallace_Beery . ?b property:start_time ?x . resource:Gloria_Swanson property:spouse ?b }
select distinct ?value  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q229232> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P26> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <http://wikidata.dbpedia.org/resource/Q322179> .
?statement <http://www.wikidata.org/entity/P580> ?value. 
} 

SELECT ?value WHERE { wd:Q229232 p:P26 ?s . ?s ps:P26 wd:Q322179 . ?s pq:P580 ?value}