what is the {start time} for {Louisville} has {twinned administrative body} as {Mainz} ?
Which was the start time for Louisville and it's twinned administrative body Mainz?
When was the start time for Louisville and its twinned administrative body Mainz?
SELECT ?o WHERE { ?o property:start_time ?o . resource:Louisville property:twinned_administrative_body ?o . ?o property:twinned_administrative_body resource:Mainz }
select distinct ?value  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q43668> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P190> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <http://wikidata.dbpedia.org/resource/Q1720> .
?statement <http://www.wikidata.org/entity/P580> ?value. 
} 

SELECT ?value WHERE { wd:Q43668 p:P190 ?s . ?s ps:P190 wd:Q1720 . ?s pq:P580 ?value}