user: Question: When did Essendon play 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: ['North Melbourne', '7.13 (55)', 'Hawthorn', '16.19 (115)', 'Arden Street Oval', 8160.0, '4 July 1981']
SQL:

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