user: Question: When is the date of vacancy of Davy FitzGerald being a replacement?
Columns: ['Team', 'Outgoing manager', 'Manner of departure', 'Date of vacancy', 'Replaced by', 'Date of appointment', 'Position']
Types: ['text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Waterford', 'Justin McCarthy', 'Resigned', '5 June 2008', 'Davy FitzGerald', '9 June 2008', 'Defeated in Munster quarter-final']
SQL:

assistant: SELECT "Date of vacancy" FROM "Table" WHERE "Replaced by" = 'Davy FitzGerald';