CREATE TABLE table_7640 ("Date" TEXT, "Tournament" TEXT, "Winning score" TEXT, "To par" TEXT, "Margin of victory" TEXT)

Which date was the Winning Score 72-66-67-71=276?
SELECT "Date" FROM table_7640 WHERE "Winning score" = '72-66-67-71=276'
SELECT "Date" FROM "table_7640" WHERE "Winning score" = '72-66-67-71=276'