The postponed 2020 Guinness Six Nations campaigns will conclude on the weekends of October 24 and 31, World Rugby has announced.
A programme of autumn internationals has also been approved by the governing body.
International rugby was halted by the coronavirus pandemic in March, leaving four Six Nations matches left to play.
World Rugby has approved a temporary global player release window between October 24 and the first weekend of December.
Ireland have outstanding Six Nations matches against Italy and France to complete, while the Italians must also host England and Wales are scheduled to face Scotland.
This year's autumn Tests are then expected to be replaced by an eight-team tournament in which the Six Nations sides will be joined by Japan and Fiji.
World Rugby chairman Sir Bill Beaumont said in a statement: "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."
