CREATE TABLE table_16504 ("Team" TEXT, "Outgoing manager" TEXT, "Manner of departure" TEXT, "Date of vacancy" TEXT, "Replaced by" TEXT, "Date of appointment" TEXT, "Position" TEXT)

When are the vacancy dates for outgoing manager Damien Fox?
SELECT "Date of vacancy" FROM table_16504 WHERE "Outgoing manager" = 'Damien Fox'
SELECT "Date of vacancy" FROM "table_16504" WHERE "Outgoing manager" = 'Damien Fox'