user: Question: On what date was Essendon 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: ['Hawthorn', '17.16 (118)', 'North Melbourne', '11.17 (83)', 'Princes Park', 16106.0, '25 April 1981']
SQL:

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