what is the {point in time} for {Edward Witten} has {award received} as {Dirac Prize} ?
When did Edward Witten get the Dirac Decoration?
When did Edward Witten receive the Dirac Medal?
SELECT ?u WHERE { ?g property:award_received resource:Dirac_Prize . resource:Edward_Witten property:award_received ?g . ?g property:point_in_time ?u }
select distinct ?value  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q201513> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P166> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <http://wikidata.dbpedia.org/resource/Q1227369> .
?statement <http://www.wikidata.org/entity/P585> ?value. 
} 

SELECT ?value WHERE { wd:Q201513 p:P166 ?s . ?s ps:P166 wd:Q1227369 . ?s pq:P585 ?value}