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 | Game site | Record |
| --- | --- | --- | --- | --- | --- |
| 1.0 | September 7 | Jacksonville Jaguars | W 17–10 | LP Field | 1–0 |
| 2.0 | September 14 | at Cincinnati Bengals | W 24–7 | Paul Brown Stadium | 2–0 |
| 3.0 | September 21 | Houston Texans | W 31–12 | LP Field | 3–0 |
| 4.0 | September 28 | Minnesota Vikings | W 30–17 | LP Field | 4–0 |
| 5.0 | October 5 | at Baltimore Ravens | W 13–10 | M&T Bank Stadium | 5–0 |
| 6.0 | Bye | Bye | Bye | Bye | Bye |
| 7.0 | October 19 | at Kansas City Chiefs | W 34–10 | Arrowhead Stadium | 6–0 |
| 8.0 | October 27 | Indianapolis Colts | W 31–21 | LP Field | 7–0 |
| 9.0 | November 2 | Green Bay Packers | W 19–16 (OT) | LP Field | 8–0 |
| 10.0 | November 9 | at Chicago Bears | W 21–14 | Soldier Field | 9–0 |
| 11.0 | November 16 | at Jacksonville Jaguars | W 24–14 | Jacksonville Municipal Stadium | 10–0 |
| 12.0 | November 23 | New York Jets | L 13-34 | LP Field | 10–1 |
| 13.0 | November 27 | at Detroit Lions | W 47–10 | Ford Field | 11–1 |
| 14.0 | December 7 | Cleveland Browns | W 28–9 | LP Field | 12–1 |
| 15.0 | December 14 | at Houston Texans | L 12-13 | Reliant Stadium | 12–2 |
| 16.0 | December 21 | Pittsburgh Steelers | W 31–14 | LP Field | 13–2 |
| 17.0 | December 28 | at Indianapolis Colts | L 0-23 | Lucas Oil Stadium | 13–3 |
Question:
When did the Titans play the Houston Texans at LP Field before Week 13?
Answer:
September 21