what is the {start time} for {Boris Johnson} has {position held} as {Member of the 56th Parliament of the United Kingdom} ?
On what date did Boris Johnson the Member of the 56th Parliament of the United Kingdom?
When was Boris Johnson the Member of the 56th  Parliament of the United Kingdom?
SELECT ?m WHERE { ?a property:start_time ?m . resource:Boris_Johnson property:position_held ?a . ?a property:position_held resource:Member_of_the_56th_Parliament_of_the_United_Kingdom }
select distinct ?value  where {
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?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/Q30524718> .
?statement <http://www.wikidata.org/entity/P580> ?value. 
} 

SELECT ?value WHERE { wd:Q180589 p:P39 ?s . ?s ps:P39 wd:Q30524718 . ?s pq:P580 ?value}