What is {head of government} of {Lisbon} that is {start time} is {2015-4-6} ?
Who became the head of the Lisbon government in April 2015?
Who was the head of the Lisbon government beginning in April 2015?
SELECT ?r WHERE { resource:Lisbon property:head_of_government ?e . ?e property:head_of_government ?r . FILTER ( CONTAINS ( YEAR ( ?k ) , '2015' ) ) . ?e property:start_time ?k }
select distinct ?obj  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q597> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P6> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?obj .
?statement <http://www.wikidata.org/entity/P580> <2015-4-6>
} 

SELECT ?obj WHERE { wd:Q597 p:P6 ?s . ?s ps:P6 ?obj . ?s pq:P580 ?x filter(contains(YEAR(?x),'2015')) }