user: Question: When did Oliver Jarvis have pole position?
Columns: ['Round', 'Circuit', 'Date', 'Pole position', 'Fastest lap', 'Winning driver', 'Winning team']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, 'Hockenheimring', '17 May', 'Mattias Ekström', 'Mattias Ekström', 'Tom Kristensen', 'Abt Sportsline']
SQL:

assistant: SELECT "Date" FROM "Table" WHERE "Pole position" = 'Oliver Jarvis';