Essex will travel to Worcestershire to begin their defence of the County Championship title that they won in 2019, while the Bob Willis Trophy Final - the end-of-season showdown also won by Essex last summer, and retained from the season's truncated schedule - will get underway at Lord's on September 27, as the ECB unveils its first-class fixture list for the reshaped 2021 campaign.
As revealed by the board in October, the format of next summer's County Championship has been altered, at this stage for one season only, to mitigate against further disruption from the Covid-19 pandemic.
In 2020, the Championship had to be abandoned, and the Bob Willis Trophy installed in its place, after the start of the season was postponed until August 1. On that occasion, the counties were split into three groups of six on a regional basis, and played five round-robin matches each ahead of the Lord's final, in which Essex once again beat Somerset - Championship runners-up in 2016, 2018 and 2019 - to confirm their status as the country's pre-eminent red-ball team.
This time, the groups have been seeded according to the team's final standings in the 2019 Championship, with a provision for local derby encounters (where they have not cut across the seeding) to enable Surrey and Middlesex, Yorkshire and Lancashire, Worcestershire and Warwickshire, Somerset and Gloucestershire, and Nottinghamshire and Derbyshire to compete in the same initial groups.
Those group stages will consist of five home and five away fixtures, with the top two counties in each then progressing to Division One, with the other counties moving into Divisions Two and Three, for a further four rounds of matches.
The side at the top of the final standings in Division One will be crowned the 2021 County Championship winners, but the runners-up will get an opportunity to compete for silverware too, with the Bob Willis Trophy being retained as a trophy in its own right, after its successful introduction last summer.
Somerset will make an immediate return to the scene of that final defeat when they face Middlesex at Lord's in the Championship's opening round in 2021, which gets underway on April 8, with all 18 counties in action.
The opening nine rounds of the Championship will begin on consecutive Thursdays, through to the first week of June, before resuming for two further rounds in July - with all 18 teams once again in action for the final set of group-stage fixtures, starting July 11.
Fixtures for the remaining domestic women's and men's white-ball competitions are set to be announced in early 2021. The postponed first season of the Hundred is due to be held in the height of the summer in July and August.
The Divisional Stage of the Championship will begin on August 30, Bank Holiday Monday, ahead of a run of late-season fixtures through to the Lord's final that the ECB hope will come to be known as "Super September".
There will be a reduction in the number of outgrounds used for the 2021 Championship, compared to the revised arrangements last summer - however, some of the more notable festival venues will again be hosting prominent fixtures, most notably Yorkshire hosting their Roses rivals Lancashire at Scarborough on July 11.
That same week, Derbyshire will play Essex at Chesterfield, Gloucestershire will play Hampshire at Cheltenham, Middlesex will play Leicestershire at Merchant Taylors, and Kent will play Sussex at Beckenham. Surrey will also face Gloucestershire at Guildford on May 27, while Glamorgan's fixture with Lancashire on June 3 is yet to be confirmed, but could take place at Colwyn Bay.
ECB Managing Director County Cricket, Neil Snowball, said: "We're all looking forward to the return of the County Championship in 2021 after a very challenging year in 2020.
"Despite the significant hurdles that we faced this year, the domestic game still found a way to play meaningful cricket across men's and women's formats while ensuring that our members and supporters were able to remain close to the game through advanced live streaming of matches.
"Once again we have seen an innovative and collaborative approach between the ECB and the 18 First Class Counties that has enabled us to plan for 2021 with a new, County Championship structure for 2021 only, that is designed to be both exciting for players and supporters and also flexible to the possible ongoing impact of COVID-19.
"We are also working hard with all 18 First-Class Counties to ensure that we are able to welcome the return of crowds safely next year and will continue to work closely with Government and all relevant authorities."
Click here to see the full list of County Championship fixtures for 2021
2021 County Championship Groups
Group 1: Essex, Warwickshire, Nottinghamshire, Derbyshire, Worcestershire, Durham
Group 2: Somerset, Hampshire, Surrey, Gloucestershire, Middlesex, Leicestershire
Group 3: Kent, Yorkshire, Lancashire, Northamptonshire, Glamorgan, Sussex