user: Question: What is the date that a game at the Alltel Stadium had a final score of 6-20?
Columns: ['Date', 'Visiting Team', 'Final Score', 'Host Team', 'Stadium']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['September 12', 'Pittsburgh Steelers', '43-0', 'Cleveland Browns', 'Cleveland Browns Stadium']
SQL:

assistant: SELECT "Date" FROM "Table" WHERE "Stadium" = 'Alltel Stadium' AND "Final Score" = '6-20';