CREATE TABLE table_38050 ("Week" TEXT, "Date" TEXT, "Kickoff" TEXT, "Opponent" TEXT, "Result" TEXT, "Record" TEXT, "Game Site" TEXT, "NFL Recap" TEXT)

Which Date had an Opponent of buffalo bills?
SELECT "Date" FROM table_38050 WHERE "Opponent" = 'buffalo bills'
SELECT "Date" FROM "table_38050" WHERE "Opponent" = 'buffalo bills'