World Rugby have confirmed that Ireland will finish their 2020 Six Nations campaign in October before the start of the new 'Eight Nations' tournament.
The World Rugby Council has approved a temporary adjustment to Regulation 9 to allow the release of international players for the revised windows.
The temporary global player release window opens from 24 October until the first weekend of December.
The Ireland men's team will face Italy in their penultimate 2020 Six Nations fixture at the Aviva Stadium on Saturday 24 October before travelling to Paris to face France on the following Saturday.
The weekend of 7 November will be a rest weekend for the players before the start of the new tournament which will see Japan and Fiji join the Six Nations teams.
Ireland will play Wales at home, England in Twickenham and Fiji back in Dublin before a play-off match with the team of equal ranking in the other pool which contains Scotland, France, Italy and Japan.
The Ireland women's team are also due to play their remaining 2020 Six Nations matches against Italy and France in the Autumn window.
World Rugby Chairman Sir Bill Beaumont said: "The global COVID-19 pandemic has been unprecedented in its impact on society and sport and throughout this process, all parties have sought to deliver the best-possible outcome to support the interests of international and club rugby and the players.
"Agreement and approval of this schedule is exciting for players and fans and an important step in supporting our unions in mitigating financial impact and optimising the sport’s return from the pandemic in an equitable way.
"These matches will be greatly anticipated by all, and I would like to thank unions, the international and club competitions and players for their input and the fans for their patience as we have sought to get international rugby back up and running."
Meanwhile, The Rugby Championship 2020 will take place over a reduced six-week period between 7 November and the second week in December with SANZAAR having asked New Zealand to host.
Special measures will need to be implemented to deal with any government-required isolation period prior to the start of the competition.