user: Question: What is the original air date for the episode with a production code of 318?
Columns: ['No. in series', 'No. in season', 'Title', 'Directed by', 'Written by', 'Original air date', 'Production code', 'Viewers (millions)']
Types: ['real', 'real', 'text', 'text', 'text', 'text', 'real', 'text']
Sample row: [41.0, 1.0, '"The Awakening"', 'Giancarlo Volpe', 'Aaron Ehasz', 'September21,2007', 301.0, 'N/A']
SQL:

assistant: SELECT "Original air date" FROM "Table" WHERE "Production code" = 318.0;