English domestic and international rugby will be played over an 11-month season under a new structure that will run for four years from 2019-2020.
The format has been agreed by the Rugby Football Union, Premiership Rugby and Rugby Players' Association, building on the framework agreed during a meeting of global stakeholders in San Francisco last year.
The Gallagher Premiership, which has traditionally run from early September to the end of May, will now start and finish later.
Twickenham will host the finals in mid to late June for the years 2020-22 with the campaigns launching on 20 October, 12 September and 18 September respectively.
England's summer tours will take place in July rather than June to leave August as the only month clear of rugby.
On two of the four years, however, the World Cup and Lions tours mean internationals will also be scheduled in August - resulting in seasons spanning 12 calendar months.
At a press conference staged to announce the new season, the RFU, PRL and RPA highlighted the initiatives introduced to improve player welfare.
England internationals will play a maximum of 30 full games per season, reduced from 32, and be confined to a limit of 35 match involvements of 20 minutes or more.
The majority of squad members involved at next year's World Cup will be stood down from the tour to Japan in July 2020 and the 2021 Lions have been guaranteed a week's rest in the following autumn series at Twickenham.
Other elements of the agreement see guaranteed in-season breaks for all players and mandatory five-week post-season rest comprising of two weeks' absolute rest and three weeks active rest.
Although there is no prospect of anyone being active across 11 or 12 months of the season, concerns have been raised over the sport's ability to maintain interest levels throughout virtually the entire calendar year.
PRL chief executive Mark McCafferty believes the domestic game will benefit, however.
"We've always held a view that the more rugby is played in better conditions and in better weather - after the Six Nations - the better," McCafferty said.
"That was one of the views that we carried into San Francisco. It was then a question of how do we marry that up with the player welfare angle.
"It's always been the case that the Premiership's stronger attendances and stronger audiences are towards the business end of the season, but that's also because you've got the firmer grounds and better weather.
"Hopefully this new structure works on a number of fronts, but there's lots still to learn in the next three years.
"This is going to continue to evolve."
A feature of the new structure is a reduction in the number of overlapping club and international games and it was confirmed that Lions tours will shorten by one week to five weeks, featuring eight matches.