On site or on call: the question that decides everything.
An on-site duty is working time: it ends a working day, and the 11 hours start from its end. On-call at home is not usually working time, except for the time spent on calls. The same night does not create the same obligations depending on how it is organised. Details in our on-call guide.
What the rules say, in a table.
The trap: the morning after.
Someone is off during the day and does an on-site night from 20:00 to 8:00. Their shift ends at 8:00: they can’t start again before 19:00, and the next morning stays off the rota. Running a full day straight into an on-site night is not just a rest question: it makes for a very long stretch of work and weighs on the weekly average.
With on-call at home, the night is not working time unless there is a call-out. If there was a call-out in the small hours, the prudent course is to count the 11 hours from its end before keeping the next morning, and to check with your adviser: the law asks for consecutive rest but doesn’t spell out this case.
What a team decides beyond the minimum.
- A full day off after every on-site night.
- The Monday off after an on-call weekend.
- A lighter week before an on-call weekend.
These are not legal obligations, but team rules that make the rota sustainable. Write them down and apply them the same way to everyone.
What Djed does, and what it doesn’t do on its own.
In Djed, rest around on-call is a set of rules on each person’s profile: “1 rest day after a night on-call” (or 2), “1 rest day after a weekend on-call”, “2 rest days in the week before an on-call weekend”. These are day-based rules: they approximate the legal rest, which is counted in hours. Once set as hard, the engine doesn’t break them when it builds the month. If you force a decision by hand, your decision stands and Djed flags it.
What Djed doesn’t do on its own: it doesn’t check the 11 hours or the weekly rest, which are counted in hours (the rest days you set are what counts), and it doesn’t record call-outs. Compliance of the rota remains the employer’s responsibility. The full method is in our out-of-hours rota guide.
Two useful next steps: to count rest from the real end of a call-out rather than a theoretical time, you need the hours actually worked, which is also a legal duty (working time records kept for three years). And to spread nights without overloading anyone, the night-work limits.
Sources and date checked.
- Organisation of Working Time Act 1997, revised edition (sections 11 to 17 and 25).
Texts checked on 5 October 2026. This guide is not legal advice: for your own situation, speak to your HR or employment adviser.
Frequently asked questions.
How much rest is needed after a night on site?
An on-site night is working time: 11 consecutive hours’ rest in every 24 (section 11 of the OWT Act 1997) before the next shift.
And after on-call at home?
On-call at home isn’t usually working time. If there was a call-out, the prudent course is to count the rest from its end and check with your adviser.