user: ### NOW ANSWER:
Question: When has a Visitor of Bulls?
Columns: ['Date', 'Visitor', 'Score', 'Home', 'Leading scorer', 'Record']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['2 December 2002', 'Cavaliers', '93–125', 'Knicks', 'Dajuan Wagner (25)', '2–17']
SQL:

assistant: SELECT "Date" FROM "Table" WHERE "Visitor" = 'Bulls';