CREATE TABLE table_28215 ("Countries and Territories" TEXT, "Conditions of access" TEXT, "Length of stay permitted" TEXT, "Fee  ( if applicable ) " TEXT, "Access using a Croatian identity card" TEXT)

What length of stay is permitted in the European Union?
SELECT "Length of stay permitted" FROM table_28215 WHERE "Countries and Territories" = 'European Union'
SELECT "Length of stay permitted" FROM "table_28215" WHERE "Countries and Territories" = 'European Union'