what is the {point in time} for {United States Postal Service} has {employees} as {546000.0} ?
Which year did the USPS employ 546,000 people?
At what point did the United States Postal Service employ 546,000 people?
SELECT ?w WHERE { resource:United_States_Postal_Service property:employees ?q . FILTER ( CONTAINS ( ?x , '546000.0' ) ) . ?q property:employees ?x . ?q property:point_in_time ?w }
select distinct ?value  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q668687> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P1128> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <546000.0> .
?statement <http://www.wikidata.org/entity/P585> ?value. 
} 

SELECT ?value WHERE { wd:Q668687 p:P1128 ?s . ?s ps:P1128 ?x filter(contains(?x , '546000.0')) . ?s pq:P585 ?value}