what is the {start time} for {Tashkent} has {country} as {Uzbekistan} ?
When did Uzbekistan make Tashkent the capital?
When did Tashkent become the capital of Uzbekistan?
SELECT ?d WHERE { resource:Tashkent property:country ?p . ?p property:start_time ?d . ?p property:country resource:Uzbekistan }
select distinct ?value  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q269> .
?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/Q265> .
?statement <http://www.wikidata.org/entity/P580> ?value. 
} 

SELECT ?value WHERE { wd:Q269 p:P17 ?s . ?s ps:P17 wd:Q265 . ?s pq:P580 ?value}