what is the {start time} for {Jim Lovell} has {spouse} as {Marilyn Lovell} ?
When did the marriage of Jim and Marilyn Lovell occur?
When did Jim Lovell marry Marilyn Lovell?
SELECT ?p WHERE { resource:Jim_Lovell property:spouse ?f . ?f property:start_time ?p . ?f property:spouse resource:Marilyn_Lovell }
select distinct ?value  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q111240> .
?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/Q21727535> .
?statement <http://www.wikidata.org/entity/P580> ?value. 
} 

SELECT ?value WHERE { wd:Q111240 p:P26 ?s . ?s ps:P26 wd:Q21727535 . ?s pq:P580 ?value}