What is {population} of {San Francisco} that is {point in time} is {1880-1-1} ?
At the beginning of 1880, what was the population of San Francisco?
What was the population of San Francisco at the beginning of 1880?
SELECT ?i WHERE { resource:San_Francisco property:population ?y . FILTER ( CONTAINS ( YEAR ( ?s ) , '1880' ) ) . ?y property:population ?i . ?y property:point_in_time ?s }
select distinct ?obj  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q62> .
?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> ?obj .
?statement <http://www.wikidata.org/entity/P585> <1880-1-1>
} 

SELECT ?obj WHERE { wd:Q62 p:P1082 ?s . ?s ps:P1082 ?obj . ?s pq:P585 ?x filter(contains(YEAR(?x),'1880')) }