user: Question: What is the date of appointment when the outgoing manager was Mustafa Denizli?
Columns: ['Team', 'Outgoing manager', 'Manner of departure', 'Date of vacancy', 'Replaced by', 'Date of appointment']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['MKE Ankaragücü', 'Roger Lemerre', 'Mutual consent', '23 May 2010', 'Ümit Özat', '24 May 2010']
SQL:

assistant: SELECT "Date of appointment" FROM "Table" WHERE "Outgoing manager" = 'Mustafa Denizli';