The 2015 Rugby World Cup in England will kick off on September 18, the International Rugby Board have confirmed.
The decision was confirmed at Tuesday's annual meeting of the IRB Council in Dublin, and is the result of an exhaustive review process which resulted in the date being recommended by chairmen and chief executives of the 10 tier-one nations.
The decision allows tournament owners Rugby World Cup Limited (RWCL), organisers England Rugby 2015 Limited (ER 2015) and the unions to step up their preparations for what is expected to be the biggest tournament to date.
IRB and RWCL chairman Bernard Lapasset said: "Throughout this collaborative process we have set out to achieve a Rugby World Cup start date that is good for participating unions, good for our other major international rugby events and ultimately good for the development of the global game.
"September 18 achieves just that and coupled with a new and robust collaborative funding model, we have collectively moved to address the challenges that face our unions during a Rugby World Cup year."The final of the tournament will be held at Twickenham on October 31. At face value the start date would appear to be a compromise. The Rugby Football Union were understood to want an early September start to ensure the tournament finished before the clocks go back.
The unions of New Zealand, Australia, South Africa and Argentina wanted a date toward the end of the month to allow the Super 15 and Rugby Championship competitions to be played in full, but the tournament dates will have a "minimal collective financial impact on participating unions and other major international rugby competitions".
ER 2015 can now press ahead with the process of confirming match schedules and venues; proposed stadiums have included Premier League football grounds Anfield, the Emirates Stadium and Old Trafford.
ER 2015 chief executive Paul Vaughan added: "ER 2015 welcomes confirmation of the start date for Rugby World Cup 2015 in England. Planning and preparation is on track and this milestone announcement further focuses our operational work as we look to deliver the best ever Rugby World Cup.
"For fans, players and all stakeholders, knowing that the Rugby World Cup 2015 will kick off on September 18 and the final will be played on October 31 at England's iconic Twickenham stadium, brings the tournament to life and really builds excitement.
"Our priority now is to confirm the tournament venues and, as we work through it, our aim is to showcase the game around the country, inspiring the largest possible audience as we prepare to welcome the global rugby family and host one of the world's largest sporting events."
The compromise over the tournament start date will also have an impact on the Aviva Premiership.
World Cup rules state that no professional domestic competitions can take place in the host nation during the tournament, meaning an additional two-week delay to the start of the 2015/16 Premiership season.
The IRB have also unveiled a collaborative supporting funding model for the tournament.
The move comes in the wake of New Zealand's assertion during last year's edition that they would not be able to compete in 2015 - due to a reduced number of home Tests during a World Cup year and having to drop their sponsors for the tournament - unless the financial model was changed.
The new model will see the IRB invest an extra £50million in the global game between 2012 and 2015, in addition to the £150million already being invested between 2009 and 2012.
The IRB have also set up a working group composed of its own representatives and those of the unions "to consider potential changes to the Rugby World Cup 2015 commercial rules proposed by the IRB to deliver overall optimal value to Unions and the IRB without impacting the ongoing growth of the tournament commercial programme".
Recommendations from this group will be presented to the RWCL board.
Lapasset said: "I am delighted that we have a unified agreement on a way forward that will promote a business partnership with our unions over the next four years to invest in the future of rugby and deliver a funding model that is good for the game as a whole and will promote the long-term strength of rugby as the sport continues to grow on all fronts."
IRB acting chief executive Robert Brophy added: "The agreed model directly addresses the challenges faced by our tier one unions by delivering an equitable business solution that promotes stability, as well as proactively addressing the issue of reduced revenues for participating unions during a Rugby World Cup year.
"This new financial model will also see investment increase across tier two and three unions, IRB regions, Sevens and strategic development tournaments."