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 | Attendance |
| --- | --- | --- | --- | --- | --- |
| 1.0 | 1963-09-08 | at Boston Patriots | L 38–14 | Fenway Park | 24,120 |
| 2.0 | Bye | Bye | Bye | Bye | Bye |
| 3.0 | 1963-09-22 | Houston Oilers | W 24–17 | Polo Grounds | 9,336 |
| 4.0 | 1963-09-28 | Oakland Raiders | W 10–7 | Polo Grounds | 17,100 |
| 5.0 | 1963-10-05 | Boston Patriots | W 31–24 | Polo Grounds | 16,769 |
| 6.0 | 1963-10-13 | at San Diego Chargers | L 24–20 | Balboa Stadium | 27,189 |
| 7.0 | 1963-10-20 | at Oakland Raiders | L 49–26 | Frank Youell Field | 15,557 |
| 8.0 | 1963-10-26 | Denver Broncos | T 35–35 | Polo Grounds | 22,553 |
| 9.0 | 1963-11-02 | San Diego Chargers | L 53–7 | Polo Grounds | 20,798 |
| 10.0 | 1963-11-10 | at Houston Oilers | L 31–27 | Jeppesen Stadium | 23,619 |
| 11.0 | 1963-11-17 | at Denver Broncos | W 14–9 | Bears Stadium | 14,247 |
| 12.0 | 1963-12-01 | Kansas City Chiefs | W 17–0 | Polo Grounds | 18,824 |
| 13.0 | 1963-12-08 | at Buffalo Bills | L 45–14 | War Memorial Stadium | 20,222 |
| 14.0 | 1963-12-14 | Buffalo Bills | L 19–10 | Polo Grounds | 6,526 |
| 15.0 | 1963-12-22 | at Kansas City Chiefs | L 48–0 | Municipal Stadium | 12,202 |
Question:
When is it has 15,557 Attendances?
Answer:
1963-10-20