World Rugby has announced a post-2019 World Cup global calendar that will include a July Test match window.
There will also be a 39% increase in fixtures between tier one and tier two nations, with tier one countries touring the Pacific Islands, Japan, Canada, United States, Georgia and Romania.
The July window - which will be moved from an existing June slot - will be followed by the current November window comprising the first three weeks of that month.
Emerging rugby powers such as Georgia will be integrated into the July and November Test programmes, with Six Nations unions collectively hosting six tier two matches during each November window.
The new arrangement, which has been approved by World Rugby's executive committee, will run from 2020 to 2032.
World Rugby said: "(The schedule) Sets new standards by prioritising rest periods, promoting equity for the sport's emerging powers and harmonising the relationship between the international and domestic games."
World Rugby chairman Bill Beaumont added: "Agreement on an optimised global calendar that provides certainty and sustainability over the decade beyond Rugby World Cup 2019 represents an historic milestone for the global game.
"But more than that, this agreement has player welfare and equity at heart, driving certainty and opportunities for emerging rugby powers and laying the foundations for a more compelling and competitive international game, which is great for unions, players and fans.
"This process has been complex, and there was no silver bullet.
"Compromise has been achieved by all stakeholders in the spirit of collaboration, and I would like to thank my union, professional league and club colleagues for their full contribution and commitment to reaching an agreement that will ultimately benefit the whole game."
World Rugby said that with agreement now reached on the season framework, discussions will continue among relevant unions regarding the duration of the RBS 6 Nations and British and Irish Lions tours.