user: Question: Who was the visiting team that played on September 15?
Columns: ['Date', 'Visiting Team', 'Final Score', 'Host Team', 'Stadium']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['September 5', 'San Francisco 49ers', '16-13', 'New York Giants', 'Giants Stadium']
SQL:

assistant: SELECT "Visiting Team" FROM "Table" WHERE "Date" = 'September 15';