What is the DuPont schedule?

The DuPont schedule is a 12-hour rotating roster for four crews on a 28-day cycle: 4 nights, 3 days off, 3 day shifts, 1 day off, 3 nights, 3 days off, 4 day shifts, then 7 days off. Each crew works 14 shifts per cycle, which averages 42 hours a week. Starting the cycle on a Monday, the weeks come out at 48, 72, 48 and 0 hours.

What is a 2-2-3 or Pitman schedule?

A 2-2-3 schedule, also called Pitman and often Panama, is a 12-hour roster on a 14-day cycle: work 2, off 2, work 3, off 2, work 2, off 3. It averages 42 hours a week and gives every other weekend off as a three-day weekend. Crews either stay on fixed days or fixed nights, or swap between days and nights every two or four weeks. Some employers use Panama only for the version where crews alternate between days and nights.

Is forward or backward shift rotation better for sleep?

Forward rotation, from day to evening to night, is generally easier. NIOSH's training course for nurses says forward rotations are easier to adjust to than backward ones. In a 2016 study of 4,750 electronics workers, backward rotation was linked to 1.95 times the odds of poor sleep quality after adjustment, and a 2010 review found that moving workers from slowly backward-rotating to rapidly forward-rotating shifts improved alertness and, to some extent, sleep.

Which rotating shift schedule is hardest on sleep?

No single schedule is worst for everyone, and NIOSH says researchers cannot recommend one best design. The features the research links to poorer sleep are backward steps from late shifts to early ones, quick returns of 11 hours or less, weekly rotation, long runs of consecutive nights, start times of 6 a.m. or earlier, and long night shifts. Southern swing, for example, rotates forward but weekly with seven nights in a row; DuPont's tightest point is three day shifts, one day off, then three nights.

Rotating Shift Schedules Explained: DuPont, Pitman, 2-2-3

A rotating schedule is a roster in which your shift times change on a repeating cycle, usually so that a fixed number of crews can cover a workplace around the clock. A handful of named patterns cover most of them. The names are used loosely, and two employers can mean different rosters by the same word, so the sequence matters more than the label.

What are the common rotating shift schedules?

D is a day shift, E an evening (afternoon or swing) shift, N a night shift. Average hours assume no overtime.

Pattern	Shift length	Sequence	Cycle	Average hours a week	Moving between days and nights
DuPont	12 h	4N, 3 off, 3D, 1 off, 3N, 3 off, 4D, 7 off	28 days	42	Four switches per cycle
Pitman / Panama (2-2-3)	12 h	2 on, 2 off, 3 on, 2 off, 2 on, 3 off	14 days	42	Fixed days or nights, or a swap every 2 or 4 weeks
4-on-4-off	12 h	4 on, 4 off; rotating version 4D, 4 off, 4N, 4 off	8 or 16 days	42	Four days off before every switch
Continental	8 h	Runs of 2 or 3 mornings, afternoons and nights, then days off	28 days	42	Forward, every 2 to 3 days
Southern swing	8 h	7D, 2 off, 7E, 2 off, 7N, 3 off	28 days	42	Forward, weekly
2-2-2 fast forward	8 h	2D, 2E, 2N, 2 off	8 days	42	Forward, every 2 days
Fixed five and two	8 h	5 on, 2 off, always the same shift	7 days	40	None

Why does almost every row say 42? A week has 168 hours. Four crews covering it in turn work 168 ÷ 4 = 42 hours each on average, whatever the shift length. What differs is how the hours bunch up. Start DuPont on a Monday and its four weeks come out at 48, 72, 48 and 0 hours. Start Pitman on a Monday and it alternates a five-shift week that includes the weekend with a two-shift week that leaves Friday to Sunday free, which is where its every-other-weekend-off reputation comes from.

Why do Pitman, Panama and 2-2-3 sound like the same thing?

Because they mostly are. Scheduling guides use all three names for the same 14-day, 12-hour cadence, and some keep Panama for the version where crews also alternate between days and nights. Continental is looser still: in some workplaces it means the 8-hour, 28-day forward rotation in the table, in others any 2-2-3 rota. If your roster has a name, write out the next 28 days as D, E, N and off. That list is what your sleep responds to.

How does each pattern move between days and nights?

Two things decide how hard a switch is: which way the clock moves, and how many hours you get between the last shift of one kind and the first of the next.

NIOSH’s free training course for nurses names the direction (Module 5). Day to evening to night is a forward rotation; night to evening to day is a backward one. It also names the speed: fast rotation changes shift within a week, slow rotation keeps each shift for two weeks or more, and weekly rotation sits in between.

In an 8-hour, three-shift system, the arithmetic is unforgiving. Move forward from a 14:00 to 22:00 afternoon to a 22:00 to 06:00 night the next day and you have 24 hours between shifts. Move backward from that night to an afternoon shift the same day and you have 8. A 22:00 finish followed by a 06:00 start also leaves 8 hours, and those 8 hours have to cover the commute, a meal and sleep.

Twelve-hour systems have only days and nights, so the gap matters more than the direction. Applied to the table:

DuPont’s tightest point is the middle of the cycle: three day shifts, one day off, three nights. The other switch, nights to days, comes after three days off.
A rotating 4-on-4-off always puts four days off between a block of days and a block of nights.
Pitman crews on fixed days or fixed nights never switch. Rotating Pitman crews switch every two or four weeks, which is a slow rotation.
Continental and 2-2-2 rosters change every two or three days, always forward.
Southern swing rotates forward but weekly, with seven nights in a row.

Why is backward rotation harder on sleep?

The usual explanation is that the human body clock runs slightly longer than 24 hours, so it is easier to push it later, as a forward rotation does, than to pull it earlier, as a backward one does.

The largest study I found on rotation direction and sleep is Shon and colleagues’ 2016 study of 4,750 Korean electronics workers on a three-shift system with 06:00, 14:00 and 22:00 starts. About 38% of the backward-rotating workers had poor sleep quality on the Pittsburgh Sleep Quality Index, against about 28% of the forward-rotating ones. After adjustment, backward rotation carried 1.95 times the odds of poor sleep, and the link was stronger in workers aged 30 and over. It was a cross-sectional study and didn’t record rotation speed, so it shows an association rather than proof.

Studies that changed people’s schedules point the same way. A review of field research by Sallinen and Kecklund (2010) found that moving workers from slowly backward-rotating to rapidly forward-rotating shifts improved alertness and, to some extent, sleep. NIOSH’s guidance says forward rotations are easier to adjust to, and that weekly rotation is the hardest speed and best avoided (Module 5, continued).

What the evidence doesn’t settle is fast versus slow. NIOSH notes that some U.S. researchers favour slow rotations of two weeks or more, which give the body clock time to adjust, while some European researchers favour fast forward rotations, which mean fewer nights in a row. Its conclusion is that it isn’t clear which is best for healthcare workers.

Why do quick returns matter so much?

A quick return is a changeover with 11 hours or less between two shifts. Vedaa and colleagues’ 2016 systematic review of 22 studies found signs that quick returns harm sleep, sleepiness and fatigue in the short term; the evidence on longer-term health and work-life balance was inconclusive. Sallinen and Kecklund saw the same pattern across shift systems: night shifts, early-morning shifts and quick returns went with shorter sleep and more sleepiness.

Eleven hours isn’t an arbitrary line. It is the minimum daily rest in the EU Working Time Directive, which allows exceptions when shift workers change shift, and the minimum gap between shifts that NIOSH’s course cites from Knauth and Hornberger. The course’s own example is an evening shift ending at 11:30 p.m. followed by a 7 or 8 a.m. day shift. Take out the drive both ways, a meal and the time it takes to fall asleep, and even a full 11 hours leaves well short of a full night.

Which schedules are hardest on sleep?

No schedule is best for everyone. NIOSH says researchers cannot recommend a single best design. Its scheduling guidelines (part 1, part 2) and the reviews above still make a fair checklist to hold a roster against:

Feature	What the guidance says	Where it turns up
Backward steps	Forward rotation is easier to adjust to	Any roster with a late finish followed by an early start
Quick returns	At least 11 hours between shifts	Backward steps in 8-hour systems, overtime added to a late shift
Weekly rotation	The hardest speed, best avoided	Southern swing
Long runs of nights	Keep consecutive nights to a minimum on rotating schedules	Southern swing (7), DuPont and rotating 4-on-4-off (4)
Early starts	6 a.m. or earlier tends to shorten sleep	06:00 mornings in Continental and other 8-hour rotations
Long night shifts	8 hours or less is better tolerated on evenings and nights	12-hour nights in DuPont, Pitman and 4-on-4-off
Rest after a run	Consider two rest days after three 12-hour shifts	DuPont’s three days, one day off, three nights

Twelve-hour shifts get a footnote. Sallinen and Kecklund found that moving from 8- to 12-hour shifts did not necessarily harm sleep. Longer shifts mean fewer changeovers and so fewer chances for a quick return, which is part of why 12-hour rosters have spread despite the long nights.

What can you do on a roster you didn’t choose?

Most people can’t redesign their schedule, but they can find its weak points. Write out a full cycle and mark every gap under 11 hours and every switch onto nights. Those are the days to protect: a nap before the first night (the night-shift sleep guide covers how long and when), nothing extra planned on the changeover day, and an honest look at whether you are fit to drive after the last night.

NIOSH also says nurses adjust better when they have some control over their schedules. If your workplace allows swaps, the backward steps and quick returns are the shifts to trade away first. If you still can’t sleep after several weeks on a rotation, the American Academy of Sleep Medicine’s page on shift work disorder describes when that becomes a conversation with a doctor.

Where AfterShift fits

I built AfterShift for people on these rosters, and it doesn’t need to know what your pattern is called. It reads shifts from your calendar, working out from the title and start time whether each is a day, evening, night or on-call shift, or you add them by hand. Then it looks at each window between the end of one shift and the start of the next, not a midnight-to-midnight day.

Two parts of it are written for the switches above. When your next shift starts earlier on the clock than the last one, a backward step, the plan calls the gap an available sleep window, notes that fast shift changes often shorten continuous sleep, and suggests a nap. When the whole gap is shorter than your sleep target, the Shift Recovery Score is capped at 79, the top of Good, because a full sleep was never possible in that window; days off are exempt. The methodology page has the weights and caps, and a sleep-debt trend shows which stretches of a cycle left you furthest behind.

None of this changes your roster. What it gives you is your own record of which changeovers cost the most sleep, which is useful evidence if you ever ask to swap them. The design post explains why the app measures shift to shift in the first place.

Rotating shift schedules explained: DuPont, Pitman, 4-on-4-off, Continental and which are hardest on sleep