CREATE TABLE table_name_76 (date VARCHAR2, bills_first_downs VARCHAR2, opponent VARCHAR2)

Which date did the oakland raiders play as the opponent when the Bills first downs were under 28?
SELECT date FROM table_name_76 WHERE bills_first_downs < 28 AND opponent = "oakland raiders"
SELECT "date" FROM "table_name_76" WHERE "bills_first_downs" < 28 AND "oakland raiders" = "opponent"