CREATE TABLE table_18039 ("Week" FLOAT, "Date" TEXT, "Opponent" TEXT, "Result" TEXT, "Game site" TEXT, "Record" TEXT, "Attendance" FLOAT)

On what day was the team playing at milwaukee county stadium?
SELECT "Date" FROM table_18039 WHERE "Game site" = 'Milwaukee County Stadium'
SELECT "Date" FROM "table_18039" WHERE "Game site" = 'Milwaukee County Stadium'