The Welsh Rugby Union (WRU) has brought forward the start date for the 2021-22 domestic league season.
Welsh rugby's governing body had originally decided to delay the season from September until January.
But following a review of the rugby and public health conditions, all divisions from Championship to Division Three will kick-off on 13 November.
However, the semi-professional Indigo Group Premiership will not start until 11 December.
That division will stage a new cup competition beginning in late September.
The top four teams in the Championship will be entered into play-offs to determine the champion club, while the Division One to Three league winners will be entered into play-offs to determine national divisional champions.
Fixtures between clubs will be played only on a home or away basis, as Welsh community rugby aims to complete the Pathway to Participation within a limited timescale.
The WRU says that to be fair to all clubs in this transitional period, there will be no promotion or relegation this season.
However, Pontypool RFC - who led the Championship table when the 2019-20 season was brought to a premature halt due to the Covid crisis - have accused the WRU of "gross mismanagement" and of making "inept and rudderless decisions".
The club say they have been "denied the opportunity to earn promotion to the WRU Indigo Premiership until 2023 at the earliest" and called for the Community Game Board to resign.
WRU community director Geraint John told BBC Radio Wales Breakfast he understood Pontypool's frustration but said he hoped they could understand the reasons behind the decision.
"We looked at the league programme; can we fit a home and away programme from the 13th November till the end?" he said.
"It's difficult to do that, in fact it can't be done and looking at the fairness, and to give Pontypool the respect they deserve - we know it [Pontypool's statement] went out publicly last night [Thursday] - I went personally to meet [chief executive] Ben Jeffreys and Pontypool, to look them in the face and to give them that news.
"It was very difficult news and obviously Pontypool are not happy with that news, but hopefully we showed them the respect that they deserve and they've done a lot for the community and for the club and we understand that element.
"We understand the promotion and relegation part but at this time we just don't know how many people are back playing.
"We said at the outset we'd bring our clubs back, financially we've supported them throughout this campaign, we're looking at our community numbers, how many people are coming back - we get regular weekly updates, how many players register, male and female, and we just don't know.
"We're getting games called off through Covid, we're having games called off as people are away at this time. So to have a full league season, with games that could be cancelled and that could determine what happens to the league programme, it was vital that we get through this season.
"Let's bring people back safely, let's help as many people as we possibly can, and I know it's not ideal - Pontypool have stated that quite clearly in their statement - but hopefully people will understand what we're trying to do to bring the game back safely, get players back and hopefully get people back excited."
The second phase of the senior women's cup competitions will take place between 21 November and the end of January. Teams will be entered into pools for this second phase depending on placings in the first phase, which is due to complete at the end of October.
There will be a break in February before the start of the women's league programme on 6 March.
The rest of the community game (youth and second XV) will follow a similar seasonal structure.
While it has been agreed that a long winter break is not currently necessary, regular, shorter breaks in the season have been built into nationally-organised competitions and are recommended at all levels.
This is to manage the continued gradual return to match fitness after such a long period without contact rugby.
For example, the senior male leagues include a two-week Christmas break and natural breaks around international weekends.
The Community Game Board agreed all clubs will receive the same Development Club Payment in the coming season as they received in the 20-21 season, plus their allocated and agreed Core Grant.
WRU chief executive Steve Phillips said: "The clubs are the lifeblood of the game in Wales and while we are thrilled to return to full-capacity internationals at Principality Stadium this autumn, it is vital that goes hand in hand with restarting grassroots rugby.
"We are committed to supporting our clubs off the field as well as on it and we hope that maintaining the same level of Core and Development payments will reassure clubs financially at a time of ongoing uncertainty."
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