user: Question: What date was Richmond the away team?
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', '12.22 (94)', 'South Melbourne', '4.7 (31)', 'MCG', 19484.0, '20 August 1955']
SQL:

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