what is the {start time} for {Willy Brandt} has {country of citizenship} as {Norway} ?
When did Willy Brandt become a citizen of Norway?
SELECT ?value WHERE { wd:Q2514 p:P27 ?s . ?s ps:P27 wd:Q20 . ?s pq:P580 ?value}
select distinct ?value  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q2514> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P27> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <http://wikidata.dbpedia.org/resource/Q20> .
?statement <http://www.wikidata.org/entity/P580> ?value. 
} 

At what point in time did Willy Brandt become a Norway citizen?