user: Question: When 1. FC Köln is the team what is the date of appointment?
Columns: ['Team', 'Outgoing manager', 'Manner of departure', 'Date of vacancy', 'Position in table', 'Replaced by', 'Date of appointment']
Types: ['text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['VfL Wolfsburg', 'Lorenz-Günther Köstner', 'End of tenure as caretaker', '30 June 2010', 'Off-season', 'Steve McClaren', '1 July 2010']
SQL:

assistant: SELECT "Date of appointment" FROM "Table" WHERE "Team" = '1. FC Köln';