user: Question: What date is the Zürich, Switzerland tournament?
Columns: ['Date', 'Tournament', 'Surface', 'Opponent in the final', 'Score']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['12 January 2003', 'Hobart, Australia', 'Hard', 'Amy Frazier', '6–2, 4–6, 6–4']
SQL:

assistant: SELECT "Date" FROM "Table" WHERE "Tournament" = 'Zürich, Switzerland';