user: Question: What Date has a Result of L 21–34?
Columns: ['Week', 'Date', 'Opponent', 'Result', 'Record', 'Game Site', 'Attendance']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'real']
Sample row: [1.0, 'September 16, 1973', 'at Cleveland Browns', 'L 14–24', '0–1', 'Cleveland Municipal Stadium', 74303.0]
SQL:

assistant: SELECT "Date" FROM "Table" WHERE "Result" = 'L 21–34';