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:
| Round | Circuit | Date | Pole position | Fastest lap | Winning driver | Winning team |
| --- | --- | --- | --- | --- | --- | --- |
| 1.0 | Hockenheimring | 17 May | Mattias Ekström | Mattias Ekström | Tom Kristensen | Abt Sportsline |
| 2.0 | EuroSpeedway Lausitz | 31 May | Mattias Ekström | Jamie Green | Gary Paffett | HWA Team |
| 3.0 | Norisring , Nuremberg | 28 June | Timo Scheider | Katherine Legge | Jamie Green | Persson Motorsport |
| 4.0 | Circuit Park Zandvoort | 19 July | Oliver Jarvis | Mattias Ekström | Gary Paffett | HWA Team |
| 5.0 | Motorsport Arena Oschersleben | 2 August | Tom Kristensen | Timo Scheider | Timo Scheider | Abt Sportsline |
| 6.0 | Nürburgring | 16 August | Martin Tomczyk | Mattias Ekström | Martin Tomczyk | Abt Sportsline |
| 7.0 | Brands Hatch , Kent | 6 September | Paul di Resta | Paul di Resta | Paul di Resta | HWA Team |
| 8.0 | Circuit de Catalunya , Barcelona | 20 September | Tom Kristensen | Timo Scheider | Timo Scheider | Abt Sportsline |
| 9.0 | Dijon-Prenois | 11 October | Bruno Spengler | Paul di Resta | Gary Paffett | HWA Team |
Question:
When did Oliver Jarvis have pole position?
Answer:
19 July