what is the {start time} for {Ryan Giggs} has {member of sports team} as {Manchester United F.C.} ?
When did Ryan Giggs join Manchester United?
When did Ryan Giggs become a member of the Manchester United F.C.?
SELECT ?n WHERE { ?n property:start_time ?n . ?n property:member_of_sports_team resource:Manchester_United_F.C. . resource:Ryan_Giggs property:member_of_sports_team ?n }
select distinct ?value  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q10524> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P54> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <http://wikidata.dbpedia.org/resource/Q18656> .
?statement <http://www.wikidata.org/entity/P580> ?value. 
} 

SELECT ?value WHERE { wd:Q10524 p:P54 ?s . ?s ps:P54 wd:Q18656 . ?s pq:P580 ?value}