North Group
Friday May 20
Leicestershire v Northamptonshire, Grace Road, Leicester
Nottinghamshire v Warwickshire, Trent Bridge, Nottingham
Worcestershire v Durham, County Ground, New Road, Worcester
Saturday May 21
Lancashire v Derbyshire, Old Trafford, Manchester
Friday May 27
Lancashire v Durham, Old Trafford, Manchester
Northamptonshire v Derbyshire, County Ground, Northampton
Warwickshire v Worcestershire, Edgbaston, Birmingham
Yorkshire v Leicestershire, Headingley, Leeds
Wednesday June 1
Durham v Nottinghamshire, Riverside Ground, Chester-le-Street
Thursday June 2
Worcestershire v Yorkshire, County Ground, New Road, Worcester
Friday June 3
Derbyshire v Leicestershire, County Ground, Derby
Lancashire v Yorkshire, Old Trafford, Manchester
Northamptonshire v Worcestershire, County Ground, Northampton
Warwickshire v Durham, Edgbaston, Birmingham
Saturday June 4
Leicestershire v Durham, Grace Road, Leicester
Nottinghamshire v Lancashire, Trent Bridge, Nottingham
Friday June 10
Lancashire v Leicestershire, Old Trafford, Manchester
Nottinghamshire v Derbyshire, Trent Bridge, Nottingham
Warwickshire v Yorkshire, Edgbaston, Birmingham
Worcestershire v Northamptonshire, County Ground, New Road, Worcester
Thursday June 16
Lancashire v Northamptonshire, Old Trafford, Manchester
Friday June 17
Derbyshire v Warwickshire, County Ground, Derby
Leicestershire v Worcestershire, Grace Road, Leicester
Northamptonshire v Durham, County Ground, Northampton
Yorkshire v Nottinghamshire, Headingley, Leeds
Saturday June 18
Worcestershire v Nottinghamshire, County Ground, New Road, Worcester
Sunday June 19
Warwickshire v Lancashire, Edgbaston, Birmingham
Yorkshire v Derbyshire, Headingley, Leeds
Friday June 24
Derbyshire v Nottinghamshire, County Ground, Derby
Durham v Yorkshire, Riverside Ground, Chester-le-Street
Lancashire v Worcestershire, Old Trafford, Manchester
Leicestershire v Warwickshire, Grace Road, Leicester
Sunday June 26
Northamptonshire v Leicestershire, County Ground, Northampton
Thursday June 30
Durham v Worcestershire, Riverside Ground, Chester-le-Street
Friday July 1
Nottinghamshire v Durham, Trent Bridge, Nottingham
Warwickshire v Northamptonshire, Edgbaston, Birmingham
Worcestershire v Derbyshire, County Ground, New Road, Worcester
Yorkshire v Lancashire, Headingley, Leeds
Sunday July 3
Derbyshire v Northamptonshire, Queen’s Park, Chesterfield
Friday July 8
Leicestershire v Derbyshire, Grace Road, Leicester
Northamptonshire v Nottinghamshire, County Ground, Northampton
Worcestershire v Lancashire, County Ground, New Road, Worcester
Yorkshire v Warwickshire, Headingley, Leeds
Saturday July 9
Nottinghamshire v Worcestershire, Trent Bridge, Nottingham
Tuesday July 12
Leicestershire v Nottinghamshire, Grace Road, Leicester
Wednesday July 13
Derbyshire v Lancashire, County Ground, Derby
Friday July 15
Durham v Northamptonshire, Riverside Ground, Chester-le-Street
Leicestershire v Lancashire, Grace Road, Leicester
Nottinghamshire v Yorkshire, Trent Bridge, Nottingham
Worcestershire v Warwickshire, County Ground, New Road, Worcester
Sunday July 17
Warwickshire v Leicestershire, Edgbaston, Birmingham
Tuesday July 19
Northamptonshire v Warwickshire, County Ground, Northampton
Wednesday July 20
Yorkshire v Durham, Headingley, Leeds
Friday July 22
Derbyshire v Worcestershire, County Ground, Derby
Durham v Lancashire, Riverside Ground, Chester-le-Street
Warwickshire v Nottinghamshire, Edgbaston, Birmingham
Yorkshire v Northamptonshire, Headingley, Leeds
Friday July 29
Durham v Derbyshire, Riverside Ground, Chester-le-Street
Lancashire v Warwickshire, Old Trafford, Manchester
Northamptonshire v Yorkshire, County Ground, Northampton
Nottinghamshire v Leicestershire, Trent Bridge, Nottingham
South Group
Friday May 20
Essex v Surrey, County Ground, Chelmsford
Gloucestershire v Sussex, County Ground, Bristol
Kent v Somerset, St Lawrence Ground, Canterbury
Thursday May 26
Surrey v Glamorgan, Kennington Oval, London
Friday May 27
Middlesex v Hampshire, Uxbridge Cricket Club Ground
Wednesday June 1
Glamorgan v Essex, Sophia Gardens, Cardiff
Sussex v Somerset, County Ground, Hove
Thursday June 2
Hampshire v Kent, The Rose Bowl, Southampton
Middlesex v Gloucestershire, Venue TBC
Friday June 3
Glamorgan v Hampshire, Sophia Gardens, Cardiff
Kent v Gloucestershire, Kent County Cricket Ground, Beckenham
Somerset v Essex, County Ground, Taunton
Sussex v Surrey, County Ground, Hove
Wednesday June 8
Kent v Hampshire, St Lawrence Ground, Canterbury
Friday June 10
Essex v Middlesex, County Ground, Chelmsford
Gloucestershire v Glamorgan, County Ground, Bristol
Somerset v Surrey, County Ground, Taunton
Sussex v Kent, County Ground, Hove
Wednesday June 15
Somerset v Glamorgan, County Ground, Taunton
Thursday June 16
Essex v Gloucestershire, County Ground, Chelmsford
Middlesex v Sussex, Lord’s, London
Friday June 17
Glamorgan v Kent, Sophia Gardens, Cardiff
Gloucestershire v Somerset, County Ground, Bristol
Hampshire v Sussex, The Rose Bowl, Southampton
Surrey v Middlesex, Kennington Oval, London
Sunday June 19
Somerset v Hampshire, County Ground, Taunton
Thursday June 23
Middlesex v Somerset, Lord’s, London
Friday June 24
Essex v Hampshire, County Ground, Chelmsford
Glamorgan v Surrey, Sophia Gardens, Cardiff
Kent v Middlesex, St Lawrence Ground, Canterbury
Saturday June 25
Hampshire v Gloucestershire, The Rose Bowl, Southampton
Surrey v Essex, Kennington Oval, London
Sunday June 26
Sussex v Gloucestershire, Arundel Castle Cricket Club Ground
Thursday June 30
Kent v Sussex, St Lawrence Ground, Canterbury
Friday July 1
Essex v Kent, County Ground, Chelmsford
Somerset v Gloucestershire, County Ground, Taunton
Surrey v Hampshire, Kennington Oval, London
Sussex v Middlesex, County Ground, Hove
Wednesday July 6
Gloucestershire v Surrey, County Ground, Bristol
Thursday July 7
Glamorgan v Sussex, Sophia Gardens, Cardiff
Somerset v Kent, County Ground, Taunton
Friday July 8
Gloucestershire v Kent, County Ground, Bristol
Hampshire v Essex, The Rose Bowl, Southampton
Middlesex v Glamorgan, Old Deer Park, Richmond
Surrey v Somerset, Kennington Oval, London
Sunday July 10
Derbyshire v Yorkshire, Queen’s Park, Chesterfield
Durham v Leicestershire, Riverside Ground, Chester-le-Street
Glamorgan v Gloucestershire, Sophia Gardens, Cardiff
Thursday July 14
Hampshire v Glamorgan, The Rose Bowl, Southampton
Friday July 15
Kent v Surrey, Nevill Ground, Tunbridge Wells
Somerset v Middlesex, County Ground, Taunton
Sussex v Hampshire, County Ground, Hove
Sunday July 17
Gloucestershire v Essex, College Ground, Cheltenham
Thursday July 21
Essex v Sussex, County Ground, Chelmsford
Middlesex v Surrey, Lord’s, London
Friday July 22
Glamorgan v Somerset, Sophia Gardens, Cardiff
Hampshire v Middlesex, The Rose Bowl, Southampton
Kent v Essex, St Lawrence Ground, Canterbury
Surrey v Sussex, Kennington Oval, London
Thursday July 28
Middlesex v Essex, Lord’s, London
Sussex v Glamorgan, County Ground, Hove
Friday July 29
Essex v Glamorgan, County Ground, Chelmsford
Gloucestershire v Middlesex, County Ground, Bristol
Hampshire v Somerset, The Rose Bowl, Southampton
Surrey v Kent, Kennington Oval, London
Quarter finals
Monday August 8 – Thursday August 11
Finals Day
Saturday August 20, Edgbaston