what is the {start time} for {Lufthansa} has {chief executive officer} as {Christoph Franz} ?
Christoph Franz became CEO of Lufthansa on what date?
When did Christoph Franz become CEO of Lufthansa?
SELECT ?i WHERE { resource:Lufthansa property:chief_executive_officer ?u . ?u property:start_time ?i . ?u property:chief_executive_officer resource:Christoph_Franz }
select distinct ?value  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q9325> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P169> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <http://wikidata.dbpedia.org/resource/Q92434> .
?statement <http://www.wikidata.org/entity/P580> ?value. 
} 

SELECT ?value WHERE { wd:Q9325 p:P169 ?s . ?s ps:P169 wd:Q92434 . ?s pq:P580 ?value}