The Heineken Champions Cup is set to resume on the weekend of September 18-20, while Daniel Dubois and Joe Joyce's heavyweight fight has been rearranged for October 24.
The Champions Cup final will take place on Saturday, October 17 and will be played a day after the Challenge Cup showpiece.
Knockout stage matches for the two tournaments, which were halted by the coronavirus pandemic, are set to be held on the weekend of September 18-20, with the semi-finals scheduled for September 25-27.
The European Professional Club Rugby says it remains committed to staging the matches in Marseille, with exact fixture dates, venues and kick-off times to be announced in the "near future".
It was also confirmed that new Champions Cup and Challenge Cup tournament formats are being considered for the 2020-21 season as a consequence of the widespread fixture disruption caused by Covid-19.
A 24-club Champions Cup, with eight representatives from each of Europe's leading leagues, is one of the options being discussed. Any changes would apply to next season's tournaments, which are scheduled to start on the weekend of December 11-13.
The all-British showdown between unbeaten heavyweights Dubois and Joyce, originally scheduled for July 11 before it was postponed due to the effects of Covid-19, will now take place on October 24 at London's O2 Arena.
Promoter Frank Warren said: "Lockdown has meant a delay, but we all want the fight to take place in October and we are hopeful that the government will give us the all clear."
Slowly plans are being put in place for cricket to resume and Middlesex have announced the club's intention for players to return to training from July 1.
It will initially be on a part-time basis, with the squad remaining on the government's job retention scheme outside their training routines, but it is another step up in preparations for the beginning of the domestic campaign.
