Night workers
A night worker is someone who usually works at least 3 hours a day during 'night time'.
By law (The Working Time Regulations 1998), night time is the period between 11pm and 6am.
Some people might call night time 'unsociable hours'.
An organisation can agree a different period of time for night time as long as it:
- is at least 7 hours long
- includes the 5 hours between 12am and 5am
The maximum hours for night workers
Night workers must not work more than 8 hours in a 24-hour period on average. Workers cannot opt out of this limit, including for overtime.
Night workers' average hours are calculated over one of the following reference periods:
- rolling periods of 17 weeks
- successive 17-week periods, if agreed and written in a relevant agreement
- if the worker has worked for fewer than 17 weeks, the period that has passed since they started work
If the work involves special hazards or heavy strain
Night workers must not work more than 8 hours in a 24-hour period if the work involves:
- special hazards
- heavy physical or mental strain
This means they must not use an average when checking their working hours.
How employers must protect night workers
Because of the possible effect on health, safety and wellbeing, employers must offer:
- anyone a health assessment before they become a night worker
- repeat assessments for as long as might be reasonable in the circumstances, for example after a change of night to day shift
Although the worker does not have to accept the offer of a health assessment, it's good practice for employers to continue to regularly check with them about their health, safety and wellbeing.
If an employee's health professional says night work is causing them health problems, the employer should offer suitable alternative work where possible.
There are extra restrictions on night working for young workers.
Keeping records of night workers' hours
By law, employers must keep records of night workers' hours to show they either:
- do not work more than an average of 8 hours in any 24-hour period
- never work for more than 8 hours in any 24-hour period if the work involves special hazards, or heavy physical or mental strain
Contact the Acas helpline
If you have any questions about night working time, contact the Acas helpline.