user: Question: What is the Date, when the Winner is Aaron Gustavson?
Columns: ['Date', 'City', 'Event', 'Winner', 'Prize']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['18–23 August 2009', 'Kiev', 'EPT Kyiv Sports Poker Championship', 'Maxim Lykov', '€330,000']
SQL:

assistant: SELECT "Date" FROM "Table" WHERE "Winner" = 'Aaron Gustavson';