Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Week | Date | Opponent | Result | Record | Attendance |
| --- | --- | --- | --- | --- | --- |
| 1.0 | September 12, 1999 | at St. Louis Rams | L 27–10 | 0–1–0 | 62,100 |
| 2.0 | September 19, 1999 | Pittsburgh Steelers | L 23–20 | 0–2–0 | 68,965 |
| 3.0 | September 26, 1999 | Cleveland Browns | W 17–10 | 1–2–0 | 68,803 |
| 4.0 | October 3, 1999 | at Atlanta Falcons | W 19–13 (OT) | 2–2–0 | 50,712 |
| 5.0 | October 10, 1999 | at Tennessee Titans | L 14–11 | 2–3–0 | 65,486 |
| 6.0 | Bye | Bye | Bye | Bye | Bye |
| 7.0 | October 21, 1999 | Kansas City Chiefs | L 35–8 | 2–4–0 | 68,771 |
| 8.0 | October 31, 1999 | Buffalo Bills | L 13–10 | 2–5–0 | 68,673 |
| 9.0 | November 7, 1999 | at Cleveland Browns | W 41–9 | 3–5–0 | 72,898 |
| 10.0 | November 14, 1999 | at Jacksonville Jaguars | L 6–3 | 3–6–0 | 67,391 |
| 11.0 | November 21, 1999 | at Cincinnati Bengals | W 34–31 | 4–6–0 | 43,279 |
| 12.0 | November 28, 1999 | Jacksonville Jaguars | L 30–23 | 4–7–0 | 68,428 |
| 13.0 | December 5, 1999 | Tennessee Titans | W 41–14 | 5–7–0 | 67,854 |
| 14.0 | December 12, 1999 | at Pittsburgh Steelers | W 31–24 | 6–7–0 | 46,715 |
| 15.0 | December 19, 1999 | New Orleans Saints | W 31–8 | 7–7–0 | 67,597 |
| 16.0 | December 26, 1999 | Cincinnati Bengals | W 22–0 | 8–7–0 | 68,036 |
| 17.0 | January 2, 2000 | at New England Patriots | L 20–3 | 8–8–0 | 50,263 |
Question:
What date did the Ravens play the buffalo bills?
Answer:
October 31, 1999