Champions Surrey will begin their County Championship title defence at home to 2017 winners Essex at The Kia Oval on April 11.
Vitality Blast champions Worcestershire will kick off their title defence at Notts, with Finals Day set for September 21.
The County Championship will move to a 10-team Division One in 2020 after an agreement was on changes to the structure.
Craig Overton became the second Somerset player in as many days to take a hat-trick as they beat Nottinghamshire at Taunton.
Tom Abell took a remarkable hat-trick as Somerset forced Nottinghamshire to follow on at Trent Bridge.
Essex's Jamie Porter and Sam Cook claimed four wickets each to condemn Surrey to a day to forget at the Kia Oval.
Centuries galore and sensational bowling performances see Sam Robson, Ian Bell and Jamie Porter make this week's team.
Durham were bowled out for their two worst scores in first-class cricket on the same day as Mohammad Abbas wreaked havoc.
Hampshire just shaded a bowler-friendly opening day against Yorkshire as 15 wickets fell on day one of their clash.
Alfred the Gorilla's winning run came to an end as Leicestershire's mascot 'outfoxed' the opposition to take the spoils...
Morne Morkel edged Surrey closer to a win over Worcestershire and their first County Championship title in 16 years.
Lancashire enjoyed an excellent opening day of their Division One relegation battle with Yorkshire at Headingley.
Surrey's seamers blew away County Championship title-holders Essex as they extended their lead at the top of Division One.
Keshav Maharaj took 7-37 as his side snatched a dramatic tie in their astonishing County Championship clash with Somerset.
Surrey skipper Rory Burns scored 90 at Essex as he became the first batsman to 1,000 County Championship runs this season.
Yorkshire and Hampshire remain in big danger of relegation after comprehensive defeats to Somerset and Essex respectively.
Surrey moved closer to their first Championship title since 2002 after crushing Nottinghamshire by an innings at The Oval.
Surrey are closing in on another Specsavers County Championship victory after making Nottinghamshire follow on at the Oval.
Mark Stoneman ended day one on 99no as leaders Surrey closed on 256-6 against third-placed Nottinghamshire at The Oval.
County Championship leaders Surrey staged an impressive recovery against Lancashire as Marcus Trescothick starred for Somerset.
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