Table:
text: 1947 Grand Prix season
Other Grands Prix
Other Grands Prix
Name_ Circuit Date_ Winning_driver Winning_constructor Report
Roussillon Grand Prix Perpignan 27 April Eugène Chaboud Talbot-Lago - Talbot Report
Jersey Road Race Saint Helier 8 May Reg Parnell Maserati Report
Marseille Grand Prix Prado 18 May Eugène Chaboud Talbot-Lago - Talbot Report
Grand Prix des Frontières Chimay 25 May Yves Giraud-Cabantous Maserati Report
Nîmes Grand Prix Nîmes 1 June Luigi Villoresi Maserati Report
Challenges AGACI Montlhéry 8 June Maurice Varet Delage Report
Marne Grand Prix Reims 6 July Christian Kautz Maserati Report
Gransden Lodge Gransden Lodge Airfield 12 July Dennis Poore Alfa Romeo Report
Albi Grand Prix Albi 13 July Louis Rosier Talbot-Lago - Talbot Report
Bari Grand Prix Lungomare 13 July Achille Varzi Alfa Romeo Report

Question: On what date did Delage win the 1947 Grand Prix season?