what is the {start time} for {Halle (Saale)} has {country} as {Soviet occupation zone} ?
During what time period was Halle (Saale) occupied by the Soviet Union?
When was Halle (Saale) a Soviet occupation zone?
SELECT ?r WHERE { resource:Halle_(Saale) property:country ?n . ?n property:start_time ?r . ?n property:country resource:Soviet_occupation_zone }
select distinct ?value  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q2814> .
?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/Q55300> .
?statement <http://www.wikidata.org/entity/P580> ?value. 
} 

SELECT ?value WHERE { wd:Q2814 p:P17 ?s . ?s ps:P17 wd:Q55300 . ?s pq:P580 ?value}