what is the {point in time} for {James Heckman} has {award received} as {Dan David Prize} ?
On what date did James Heckman receive the Dan David Prize?
When did James Heckman receive the award Dan David Prize?
SELECT ?g WHERE { ?c property:award_received resource:Dan_David_Prize . resource:James_Heckman property:award_received ?c . ?c property:point_in_time ?g }
select distinct ?value  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q312561> .
?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/Q1158951> .
?statement <http://www.wikidata.org/entity/P585> ?value. 
} 

SELECT ?value WHERE { wd:Q312561 p:P166 ?s . ?s ps:P166 wd:Q1158951 . ?s pq:P585 ?value}