ShiftLens

Night workers: the 8-hour average and health assessments

Staff who regularly work at least 3 hours during the night period are night workers. They shouldn't work more than an average of 8 hours in every 24, and they must be offered a free health assessment. Unlike the 48-hour week, workers can't opt out of the night work limit.

ShiftLens provides guidance, not legal advice. This guide is a summary for England, Scotland and Wales. Some rules have exceptions, and contracts or workforce agreements can change some of the details. For advice on your situation, contact Acas or an employment solicitor.

Who is a night worker

The night period is 11pm to 6am, unless the worker and employer agree a different one in writing. An agreed night period must be 7 hours long and include midnight to 5am.

Someone is a night worker if they regularly work at least 3 hours of their working day in the night period. The regulations count it as regular if they do so on most of the days they work. A collective agreement can also say that someone's work is night work.

The 8-hour average

Night workers shouldn't work more than an average of 8 hours in each 24-hour period. The average is usually worked out over 17 weeks, or up to 52 weeks if the workers and employer agree, for example by collective agreement. Regular overtime counts towards the average, but occasional overtime doesn't. Workers can't opt out.

If the work involves special hazards or heavy physical or mental strain, there's a stricter limit: no more than 8 hours in any 24 hours in which they do night work.

The National Minimum Wage applies to night work, but there isn't a higher night rate.

Health assessments

Employers must offer a free health assessment before someone becomes a night worker, and regularly after that. Workers don't have to accept. Employers must keep confidential records of the assessments, and of the dates they were offered, for 2 years.

Under-18s who work in the restricted period (usually 10pm to 6am) must be offered a free assessment of their health and capacities. See night work rules for under-18s.

Exceptions

gov.uk says the limits don't apply in some situations, including jobs that need round-the-clock staffing and industries with busy peak periods, such as retail and tourism, or where a collective or workforce agreement changes them. If you're not sure whether an exception applies to you, contact Acas.

How ShiftLens checks this

ShiftLens treats someone as a likely night worker if they work at least 3 hours between 11pm and 6am on more than half of the days they're rostered. It then shows their average hours per 24 across the rota as a note, because the legal average usually runs over 17 weeks, and the rota can't show overtime arrangements or exceptions.

Check your rota for this

ShiftLens spots people who look like night workers from their shifts, and shows their average hours across the rota. It's free, there's no sign-up, and your rota never leaves your browser.

Check your rota

Sources

gov.uk: night working hours; gov.uk: health assessments; gov.uk: exceptions to night work limits; Working Time Regulations 1998, regulation 6; regulation 7; regulation 2 (night time, night worker)