what is the {point in time} for {Metro Manila} has {population} as {7.94839e+06} ?
When did Metro Manila have a population of 794,839?
SELECT ?value WHERE { wd:Q13580 p:P1082 ?s . ?s ps:P1082 ?x filter(contains(?x,'7.94839e+06')) . ?s pq:P585 ?value}
select distinct ?value  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q13580> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P1082> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <7.94839e+06> .
?statement <http://www.wikidata.org/entity/P585> ?value. 
} 

Name the date the city of Manila has a population of 794,839.