user: Question: what are the u.s. air dates with a Canadian air date of May 4, 2009
Columns: ['Season #', 'Series #', 'Title', 'Canadian airdate', 'U.S. airdate', 'Production code']
Types: ['real', 'real', 'text', 'text', 'text', 'real']
Sample row: [1.0, 14.0, '"Dangerous Liaisons"', 'April 21, 2009', 'April 3, 2009', 201.0]
SQL:

assistant: SELECT "U.S. airdate" FROM "Table" WHERE "Canadian airdate" = 'May 4, 2009';