what is the {start time} for {York} has {country} as {Kingdom of Great Britain} ?
On what date did York turned into a country in the UK?
When did York become a country in the Kingdom of Great Britain?
SELECT ?h WHERE { resource:York property:country ?z . ?z property:start_time ?h . ?z property:country resource:Great_Britain }
select distinct ?value  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q42462> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P17> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <http://wikidata.dbpedia.org/resource/Q161885> .
?statement <http://www.wikidata.org/entity/P580> ?value. 
} 

SELECT ?value WHERE { wd:Q42462 p:P17 ?s . ?s ps:P17 wd:Q161885 . ?s pq:P580 ?value}