CREATE TABLE table_12538 ("Week" FLOAT, "Date" TEXT, "Opponent" TEXT, "Result" TEXT, "Attendance" TEXT)

Which Opponent has a Date of september 20, 1992?
SELECT "Opponent" FROM table_12538 WHERE "Date" = 'september 20, 1992'
SELECT "Opponent" FROM "table_12538" WHERE "Date" = 'september 20, 1992'