what is the {start time} for {Ibaraki Prefecture} has {head of government} as {Masaru Hashimoto} ?
When did Ibaraki Prefecture replace Masaru Hashimoto as head of governement?
When did Ibaraki Prefecture become head of government instead of Masaru Hashimoto?
SELECT ?d WHERE { ?g property:start_time ?d . resource:Ibaraki_Prefecture property:head_of_government ?g . ?g property:head_of_government resource:Masaru_Hashimoto }
select distinct ?value  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q83273> .
?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> <http://wikidata.dbpedia.org/resource/Q982631> .
?statement <http://www.wikidata.org/entity/P580> ?value. 
} 

SELECT ?value WHERE { wd:Q83273 p:P6 ?s . ?s ps:P6 wd:Q982631 . ?s pq:P580 ?value}