what is the {start time} for {Stephen Harper} has {position held} as {Prime Minister of Canada} ?
Stephen Harper became Prime Minister of Canada on what date?
When did Stephen Harper begin his term as Prime Minister of Canada?
SELECT ?q WHERE { ?p property:position_held resource:Prime_Minister_of_Canada . resource:Stephen_Harper property:position_held ?p . ?p property:start_time ?q }
select distinct ?value  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q206> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P39> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <http://wikidata.dbpedia.org/resource/Q839078> .
?statement <http://www.wikidata.org/entity/P580> ?value. 
} 

SELECT ?value WHERE { wd:Q206 p:P39 ?s . ?s ps:P39 wd:Q839078 . ?s pq:P580 ?value}