what is the {start time} for {Rennes} has {head of government} as {Henri Fréville} ?
Date Henri Freville became head of Rennes government?
When did Henri Fréville become the head of government of Rennes?
SELECT ?d WHERE { ?y property:head_of_government resource:Henri_Fréville . ?y property:start_time ?d . resource:Rennes property:head_of_government ?y }
select distinct ?value  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q647> .
?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/Q3131134> .
?statement <http://www.wikidata.org/entity/P580> ?value. 
} 

SELECT ?value WHERE { wd:Q647 p:P6 ?s . ?s ps:P6 wd:Q3131134 . ?s pq:P580 ?value}