what is the {valid in period} for {Sofia} has {located in time zone} as {UTC+03:00} ?
At what point was Sofia found in the UTC+03:00 time zone?
When was Sofia located in the time zone of UTC+03:00?
SELECT ?g WHERE { ?n property:located_in_time_zone resource:UTC+03:00 . resource:Sofia property:located_in_time_zone ?n . ?n property:valid_in_period ?g }
select distinct ?value  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q472> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P421> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <http://wikidata.dbpedia.org/resource/Q6760> .
?statement <http://www.wikidata.org/entity/P1264> ?value. 
} 

SELECT ?value WHERE { wd:Q472 p:P421 ?s . ?s ps:P421 wd:Q6760 . ?s pq:P1264 ?value}