user: Question: On what date is the winning team Abt Sportsline and pole position Mattias Ekström in the Circuit Ricardo Tormo , Valencia?
Columns: ['Round', 'Circuit', 'Date', 'Pole Position', 'Fastest Lap', 'Winning Driver', 'Winning Team']
Types: ['text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['1', 'Hockenheimring', '1 May', 'Bruno Spengler', 'Bruno Spengler', 'Bruno Spengler', 'HWA Team']
SQL:

assistant: SELECT "Date" FROM "Table" WHERE "Winning Team" = 'Abt Sportsline' AND "Pole Position" = 'Mattias Ekström' AND "Circuit" = 'Circuit Ricardo Tormo , Valencia';