what is the {start time} for {Delft} has {head of government} as {Marja van Bijsterveldt} ?
Marja Van Bijsterveldt took over the municipal council in what year?
When did Marja van Bijsterveldt start as the head of the municipal council?
SELECT ?g WHERE { ?e property:start_time ?g . resource:Delft property:head_of_government ?e . ?e property:head_of_government resource:Marja_van_Bijsterveldt }
select distinct ?value  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q690> .
?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/Q434650> .
?statement <http://www.wikidata.org/entity/P580> ?value. 
} 

SELECT ?value WHERE { wd:Q690 p:P6 ?s . ?s ps:P6 wd:Q434650 . ?s pq:P580 ?value}