The 2020 Siam Cup will be played at Footes Lane in Guernsey on Saturday 2 May after Jersey Reds agreed to the hosts' proposed date.
There had been some doubts over the historic fixture taking place this year because of a clash with the Reds' penultimate league game of the season.
But following a meeting a club's board, Jersey have agreed to travel on the date put forward by Guernsey, albeit with their squad selection likely to be affected.
The Reds' Championship schedule runs later than usual this season because of the Rugby World Cup, finishing with a trip to Coventry on 9 May.
Jersey hold three of the four trophies contested for on Siam Cup day, having taken the veterans and seconds matches in 2019, as well as regaining the Siam Cup itself.