Title-holders Sussex will begin their 2008 Championship campaign with a visit to the Rose Bowl to take on Hampshire.
Sussex have won the title in three of the last five seasons
It will be a tough start for Chris Adams's side, who hope to become the first side since the 1960s to win the title in three successive years.
The first round of games, which begin on 16 April, also feature Surrey against Lancashire and Kent v Notts.
But they will be preceded on 10 April by the annual curtain-raiser between Sussex and an MCC XI at Lord's.
"We have a terrific group of fellows who are both candid and respectful of the success they have had," Adams told ecb.co.uk.
"It is borne out of good honest hard work and graft and that is the recipe for more of the same so why not a fourth championship title in 2008?"
The scheduling of the various one-day competitions will follow the same basic format used for the past two seasons with the early stages of Friends Provident Trophy followed by the Twenty20 Cup and then finally the NatWest Pro40 league.
The opening round of Trophy games will take place on 20 April, with holders Durham meeting Yorkshire at the Riverside.
In a change from last year, the 18 county sides plus Ireland and Scotland will be divided into four groups of five, with the top two from each group progressing to the quarter-finals.
The groups are:
South/West: Glamorgan, Gloucestershire, Hampshire, Somerset, Worcestershire
South/East: Essex, Kent, Middlesex, Surrey, Sussex
Midlands: Ireland, Leicestershire, Northamptonshire, Nottinghamshire, Warwickshire
North: Derbyshire, Durham, Lancashire, Scotland, Yorkshire
The final of the competition will take place at Lord's on 16 August.
By then, the first silverware of the summer will already have been presented, with Twenty20 Cup finals day at the Rose Bowl, which features the semi-finals and final, set for 26 July.
The group stage of the competition will take place between 11 and 27 June, with quarter-finals from 7 to 9 July.
The Pro40 begins on 15 July with a match between defending champions Worcestershire Royals and the Nottinghamshire Outlaws, the first of 24 fixtures to be played under floodlights.