user: Question: Which date did Richmond play as away?
Columns: ['Home team', 'Home team score', 'Away team', 'Away team score', 'Venue', 'Crowd', 'Date']
Types: ['text', 'text', 'text', 'text', 'text', 'real', 'text']
Sample row: ['Melbourne', '21.15 (141)', 'St Kilda', '31.18 (204)', 'MCG', 24852.0, '6 May 1978']
SQL:

assistant: SELECT "Date" FROM "Table" WHERE "Away team" = 'Richmond';