what is the {start time} for {Peter Freuchen} has {member of political party} as {Social Democrats} ?
In which year did Peter Freuchen become a member of the Social Democrats?
When did Peter Freuchen join the Social Democrats?
SELECT ?p WHERE { ?b property:start_time ?p . ?b property:member_of_political_party resource:Social_Democrats . resource:Peter_Freuchen property:member_of_political_party ?b }
select distinct ?value  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q945641> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P102> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <http://wikidata.dbpedia.org/resource/Q212101> .
?statement <http://www.wikidata.org/entity/P580> ?value. 
} 

SELECT ?value WHERE { wd:Q945641 p:P102 ?s . ?s ps:P102 wd:Q212101 . ?s pq:P580 ?value}