user: Question: On what date was the away team West Ham United?
Columns: ['Tie no', 'Home team', 'Score', 'Away team', 'Date']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['1', 'Bournemouth', '1–1', 'Manchester United', '18 February 1989']
SQL:

assistant: SELECT "Date" FROM "Table" WHERE "Away team" = 'West Ham United';