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:
| Grand Prix | Date | Location | Pole Position | Fastest Lap | Winning Driver | Constructor | Report |
| --- | --- | --- | --- | --- | --- | --- | --- |
| Brazilian Grand Prix | 3 April | Jacarepaguá | Ayrton Senna | Gerhard Berger | Alain Prost | McLaren - Honda | Report |
| San Marino Grand Prix | 1 May | Imola | Ayrton Senna | Alain Prost | Ayrton Senna | McLaren - Honda | Report |
| Monaco Grand Prix | 15 May | Monaco | Ayrton Senna | Ayrton Senna | Alain Prost | McLaren - Honda | Report |
| Mexican Grand Prix | 29 May | Hermanos Rodríguez | Ayrton Senna | Alain Prost | Alain Prost | McLaren - Honda | Report |
| Canadian Grand Prix | 12 June | Circuit Gilles Villeneuve | Ayrton Senna | Ayrton Senna | Ayrton Senna | McLaren - Honda | Report |
| Detroit Grand Prix | 19 June | Detroit | Ayrton Senna | Alain Prost | Ayrton Senna | McLaren - Honda | Report |
| French Grand Prix | 3 July | Paul Ricard | Alain Prost | Alain Prost | Alain Prost | McLaren - Honda | Report |
| British Grand Prix | 10 July | Silverstone | Gerhard Berger | Nigel Mansell | Ayrton Senna | McLaren - Honda | Report |
| German Grand Prix | 24 July | Hockenheimring | Ayrton Senna | Alessandro Nannini | Ayrton Senna | McLaren - Honda | Report |
| Hungarian Grand Prix | 7 August | Hungaroring | Ayrton Senna | Alain Prost | Ayrton Senna | McLaren - Honda | Report |
| Belgian Grand Prix | 28 August | Spa-Francorchamps | Ayrton Senna | Gerhard Berger | Ayrton Senna | McLaren - Honda | Report |
| Italian Grand Prix | 11 September | Monza | Ayrton Senna | Michele Alboreto | Gerhard Berger | Ferrari | Report |
| Portuguese Grand Prix | 25 September | Estoril | Alain Prost | Gerhard Berger | Alain Prost | McLaren - Honda | Report |
| Spanish Grand Prix | 2 October | Jerez | Ayrton Senna | Alain Prost | Alain Prost | McLaren - Honda | Report |
| Japanese Grand Prix | 30 October | Suzuka | Ayrton Senna | Ayrton Senna | Ayrton Senna | McLaren - Honda | Report |
| Australian Grand Prix | 13 November | Adelaide | Ayrton Senna | Alain Prost | Alain Prost | McLaren - Honda | Report |
Question:
What date is the Portuguese Grand Prix?
Answer:
25 September