Table:
text: 1978 British Formula One season
Races
Races
Round Name_ Circuit Date_ Winning_driver Winning_car
1 International Gold Cup Oulton Park March 24 Tony Trimmer McLaren M23
2 Evening News Trophy Brands Hatch March 27 Tony Trimmer McLaren M23
3 Anglia TV Trophy Snetterton April 16 Tony Trimmer McLaren M23
4 Sun Trophy Mallory Park May 1 Geoff Lees Ensign N175
5 International Whitsuntide Race Zandvoort May 15 Bob Evans Surtees TS19
6 Donington Formula 1 Trophy Donington Park May 21 Giancarlo Martini Ensign N175
7 Radio 210 European Trophy Thruxton May 29 Tony Trimmer McLaren M23
8 Oulton Park Formula 1 Trophy Oulton Park June 24 Guy Edwards March 781

Question: What date was the International Gold Cup held in the 1978 British Formula 1 season?