CREATE TABLE table_12596 ("State" TEXT, "Status" TEXT, "Association Agreement" TEXT, "Membership Application" TEXT, "Candidate status" TEXT, "Negotiations start" TEXT, "Screening completed" TEXT, "Acquis Chapters open/closed" TEXT)

What is the acquis chapter open/closed dates with a membership application in 2009-04-28?
SELECT "Acquis Chapters open/closed" FROM table_12596 WHERE "Membership Application" = '2009-04-28'
SELECT "Acquis Chapters open/closed" FROM "table_12596" WHERE "Membership Application" = '2009-04-28'