How many {day in year for periodic occurrence} are for {Passover} ?
How many days out of the year is Passover?
How many days in a year for the {Passover} ?
SELECT ( COUNT ( ?s ) AS ?p ) { resource:Passover property:day_in_year_for_periodic_occurrence ?s }
SELECT (COUNT(?obj) AS ?objs ) {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q121393> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P837> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?obj .
} 

SELECT (COUNT(?obj) AS ?value ) { wd:Q121393 wdt:P837 ?obj }
8