County Championship: Champions Essex to start 2018 season at Headingley
Champions Essex will begin the defence of their County Championship title against Yorkshire at Headingley.
The 2018 season starts on Friday, 13 April with three games in Division One and three in Division Two.
Middlesex, relegated in 2017 a year after being crowned champions, begin against Northants at Lord's.
Last season's two promoted teams, Worcestershire and Nottinghamshire, travel to Hampshire and Lancashire respectively.
The season starts a week later than in 2017, while the final round of fixtures starts on Monday, 24 September, a day earlier than in 2017.
Counties play 14 matches in a season. Each county in Division Two, which features 10 teams, play five sides twice and four teams once.
Following their trip to Leeds, Essex's opening home fixture is against Lancashire, starting on 20 April.
Opening round of 2018 County Championship fixtures (13-16 April)
- Division One: Yorkshire v Essex, Hampshire v Worcestershire, Lancashire v Nottinghamshire
- Division Two: Kent v Gloucestershire, Warwickshire v Sussex, Middlesex v Northamptonshire
The One-Day Cup final will take place on Saturday, 30 June at Lord's, and T20 Finals Day is on Saturday, 15 September at Edgbaston.
Lancashire and Yorkshire meet in the first Roses match of the season at Old Trafford on Sunday, 22 July, with the reverse fixture starting on Monday, 10 September.
There will be nine day-night championship games spread throughout the summer, rather than all in late June like last season, but the limited-overs competitions follow a similar pattern to 2017.
All of the One-Day Cup group games are in May and early June - starting on 17 May - as the County Championship takes a four-week break.
The T20 Blast runs throughout July and August, beginning on 4 July, with a reduced schedule of four-day cricket in that period.
Notts won both domestic limited-overs trophies in 2017.