CREATE TABLE table_35904 ("Date" TEXT, "Tournament" TEXT, "Winning score" TEXT, "Margin of victory" TEXT, "Runner ( s ) -up" TEXT)

On what Date was Patty Sheehan Runner(s)-up?
SELECT "Date" FROM table_35904 WHERE "Runner(s)-up" = 'patty sheehan'
SELECT "Date" FROM "table_35904" WHERE "Runner(s)-up" = 'patty sheehan'