CREATE TABLE table_39706 ("Date" TEXT, "Opponent" TEXT, "Score" TEXT, "Loss" TEXT, "Attendance" TEXT, "Record" TEXT)

What was the date of the game with a score of 15 6?
SELECT "Date" FROM table_39706 WHERE "Score" = '15–6'
SELECT "Date" FROM "table_39706" WHERE "Score" = '15–6'