How to Build a 4-on-4-off Rota (With a Worked 8-Week Example)

4-on-4-off was built for operations that never close: control rooms, care settings with overnight staff, warehouses on continuous shifts, security, manufacturing lines and emergency services. Each person works four consecutive 12-hour shifts, then has four consecutive days off. Because the cycle is eight days long, it drifts against the calendar, so your weekends off move. Some staff love that they get a long weekend every other cycle. Others hate that they can never promise to be free every Saturday.

It suits a team when three things are true. The work genuinely needs cover for all 24 hours, or at least for two 12-hour blocks. The team is large enough to be split into four groups of roughly equal skill. And the people on it are willing to trade long shifts for long breaks. If your site closes overnight, or your team is five people, a fixed weekday pattern or a staggered pattern will serve you better.

The arithmetic is simple once you see it. With a single 12-hour shift per day (say, 07:00 to 19:00), you need two teams: one working while the other rests. With day and night shifts, you need four teams: two teams cover the day and night on any given date, and two are off. If you also want a fifth team so that annual leave and training can be absorbed without overtime, that is a "4-on-4-off with relief" pattern, which we cover at the end.

Decide the minimum headcount per shift first, not the team size. If a shift needs three people to run safely, each team needs three people, plus whatever margin you want for absence. A team of exactly three has no slack: one sick day means a short shift or a call-in. A team of four gives you one spare per shift, which in practice covers most sickness without overtime.

Give each team a letter and start them four days apart. Team A works days 1 to 4 and rests days 5 to 8. Team B starts on day 5. With days and nights, Team C mirrors A on nights and Team D mirrors B. The table below shows the first 16 days with a single day shift, which is the easiest version to check by eye: every date has exactly one team on, and every team gets exactly four off after four on.

Now the full version. Four teams, days and nights, shown as an 8-week block because 56 days is the point at which the pattern has drifted a full week against the calendar and starts again on the same weekday. Each row is one team; each column is one week of Monday to Sunday. D is a day shift, N a night shift.

Read any column downwards and you will find exactly one D team and one N team on every date. Read any row across and you will find the on-off rhythm never breaks. That is the whole test. If either check fails after you have edited the rota, something has been dropped.

Here is the trap. Four 12-hour shifts is 48 hours, and four days off is zero, so the cycle averages 24 hours a day over 8 days, which is 42 hours a week. Over a year that is roughly 2,190 hours, against about 1,950 for a standard 37.5-hour contract. Staff on 4-on-4-off are working a longer year than their office colleagues, and their contracts and pay need to say so.

Because some individual weeks contain five or six 12-hour shifts, the pattern only stays lawful in the UK through the 17-week averaging in the Working Time Regulations, or through a signed opt-out. Do not rely on the opt-out alone: rest breaks between shifts and the 24-hour weekly rest still apply, and a night team needs the night-worker health assessment offer.

In the table above, Teams A and B always work days and C and D always work nights. That is a fixed-nights model: simple, and preferred by many night workers who have built their lives around it. The alternative is a rotating model where each team swaps between days and nights every cycle or every few cycles. Rotation shares the burden of nights but is harder on sleep, and the switch from a night block to a day block needs at least 48 hours off in between, which the plain pattern does not guarantee.

If you rotate, rotate forwards (days, then nights, then off) and never ask a team to finish a night block and start a day block within the same rest period. Write the rotation into the pattern rather than handling it by hand, so the rest gap is checked every cycle rather than remembered by whoever writes next month's rota.

1. Trimming shifts to fix the hours. Cutting a 12-hour shift to 10 hours to hit a 35-hour contract leaves a 4-hour hole in every day. Fix the contract or add a short overlap shift, not the pattern.
2. Uneven teams. If Team C has two experienced people and Team D has none, every other night is a risk. Balance skills across teams before you balance headcount.
3. Handling leave by borrowing. Pulling someone from their off block to cover a colleague's leave destroys the rest rhythm that makes the pattern bearable. Use a relief team or planned overtime instead.
4. Forgetting the calendar drift. The pattern moves a day earlier each week against the calendar, so a team that has Christmas off this year will work it in a future year. Publish a 12-month view so people can see it coming.
5. Editing one team without re-checking the column. Every change should be followed by the two checks from Step 2: one day team and one night team on every date, and the on-off rhythm intact on every row.

Annual leave on 4-on-4-off is taken in shifts, not days. A person who books their four working days off gets twelve consecutive days away for four shifts of leave, which is one of the pattern's quiet advantages. Your leave policy should state the entitlement in hours or shifts so that nobody argues about whether a "day" of leave is 7.5 or 12 hours.

Swaps are safest within the same team position: A-days swapping with B-days keeps everyone on the same shift type. A swap between a day team and a night team needs the rest-gap check again. Our guide on handling shift swaps fairly has a simple approval rule that works for continuous patterns, and covering annual leave in small teams covers the relief-team maths.

Whatever tool you use, build the pattern once as a repeating template and generate dates from it, rather than typing 365 days by hand. In Roster Champion the Pattern Editor takes an 8-day cycle per team and rolls it forward; the coverage check then flags any date where the day or night count drops below your minimum, which is exactly the column check from Step 2 done for you.

Before you publish, print the 8-week view and hand it to the people who will work it. They will spot the Christmas problem, the football-final problem and the school-run problem faster than any check can.