What is the open and closed period of the British Museum that every weekend is open?
SELECT ?value1 ?value2 WHERE { wd:Q6373 p:P3025 ?s . ?s ps:P3025 wd:Q26214163 . ?s pq:P3027 ?value1 . ?s pq:P3026 ?value2 }
british museum: Q6373 all weekdays: Q26214163