what is the {start time} for {Karl Pearson} has {member of} as {American Academy of Arts and Sciences} ?
What was the date that Karl Person began his membership at the American Academy of Arts and Sciences?
When did Karl Pearson become a member of the American Academy of Arts and Sciences?
SELECT ?x WHERE { ?b property:start_time ?x . ?b property:member_of resource:American_Academy_of_Arts_and_Sciences . resource:Karl_Pearson property:member_of ?b }
select distinct ?value  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q310794> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P463> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <http://wikidata.dbpedia.org/resource/Q463303> .
?statement <http://www.wikidata.org/entity/P580> ?value. 
} 

SELECT ?value WHERE { wd:Q310794 p:P463 ?s . ?s ps:P463 wd:Q463303 . ?s pq:P580 ?value}