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Working hours

The way working hours are arranged can help an organisation to manage its business and help workers balance their responsibilities at work and at home. Many businesses are under pressure to satisfy demands 24/7, and must balance this with the needs of their workers. This is leading to a more flexible working approach, which includes flexible start and finish times, shift work, job sharing or home-working.

Key points

The Working Time Regulations govern the hours most workers can work and set:

  • limits on an average working week
  • statutory entitlement to paid leave for most workers
  • limits on the normal hours of night work and regular health assessments
  • special regulations for young workers.

Working hours

The Working Time Regulations determine the maximum weekly working time, patterns of work and holidays, plus the daily and weekly rest periods. They also cover the health and working hours of night workers. The Regulations apply to both part time or full-time workers, including the majority of agency workers and freelancers, although certain categories of workers are excluded.

In general the Working Time Regulations provide rights to:

  • a limit of an average 48 hours a week on the hours a worker can be required to work, though individuals may choose to work longer by "opting out"
  • paid annual leave of 5.6 weeks' a year
  • 11 consecutive hours' rest in any 24-hour period
  • a 20-minute rest break if the working day is longer than six hours
  • one day off each week
  • a limit on the normal working hours of night workers to an average eight hours in any 24-hour period, and an entitlement for night workers to receive regular health assessments.

There are special regulations for young workers, which restrict their working hours to 8 hours per day and 40 hours per week. The rest break is 30 minutes if their work lasts more than 4.5 hours. They are also entitled to two days off each week.

Any proposals to change patterns of working are best carried out in a consultative way, explaining the reasons behind such a move and the benefits which may accrue to both the organisation and worker.

Working Time Directive - Mobile workers - September 2015

The European Court of Justice, in a recent case gave the judgement that mobile workers who have no fixed place of work, and spend time travelling from home to the first and last customer should have this time considered as working time. The Court added that because the workers are at the employer's disposal for the time of the journeys, they act under their employer's instructions and cannot use that time freely to pursue their own interest.

Acas is assessing the impact of this judgement on workers and employers in Great Britain and will provide more detailed guidance when it is available.

Employers and employees should be aware that this may have an impact on breaks if the working day is extended as a result of travelling time. It is also worth checking employment contracts to see what they say about travelling time.


Overtime is normally hours that are worked above the normal full time hours, normal working hours are the hours mentioned in the terms of employment. Overtime can be voluntary or compulsory. Compulsory overtime would form part of the terms and conditions of employer.

There is no legal right to be paid extra for any overtime worked, this may be detailed in the terms of employment.

Night working

A night worker is someone who normally works at least 3 hours during the night period, which is the period between 11pm to 6am, unless the worker and employer agree a different night period.

Night workers should not work more than an average of 8 hours in 24-hour period. This average is usually calculated over a 17 week reference period, but it can be over a longer period if the workers and employer agree. Regular overtime is included in the average and workers can't opt out of this limit.

Employers must offer workers a free health assessment before they become a night worker and on a regular basis while they are working nights. Workers do not have to accept this health check.

48 hour working week

Normally most workers don't have to work on average more than 48 hours per week unless they agree to. If workers agrees to work beyond the 48-hour limit they must put it in writing, this is generally known at an opt-out. Workers have the right to cancel the opt-out agreement, although they must give their employer at least 7 days' notice - a longer period of notice may be agreed by the employer, but it can be no longer than 3 months.

The average working week is calculated by taking the average over a 17 week reference period.

Young people (16 and 17 year olds) normally cannot opt-out of the 48 hour working week, as they may not normally work more than a 40 hours per week.

Compensatory rest

In some circumstances a worker may be required to work during a rest period and may have to take rest later, this is known as compensatory rest. Compensatory rest is normally the same length of time as the break or part of the break that a worker has missed.

Written statement

Working hours should be included in a document called a Written Statement - terms and conditions of employment provided for all employees by their employer. You may also be interested in Acas guidance on Zero hours contracts

Further guidance and resources can be found on Acas Helpline Online  

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View Acas training courses on Contracts and hours: how Acas can help or find out how our business services can help your organisation.

This topic is addressed in Acas Employment Law Update training. View course listings. You may also benefit from viewing our Employment Law Update timetable.

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