DuPont Schedule: How the 4-Crew 12-Hour Rotation Works

The DuPont schedule is a 24/7 shift pattern that uses four teams working 12-hour shifts on a 28-day cycle. Each team works 4 nights, has 3 days off, works 3 days, has 1 day off, works 3 nights, has 3 days off, works 4 days, then gets 7 days off in a row. It averages 42 hours a week. This guide shows the full rotation, the staffing math, the overtime it creates under federal and California law, and what to set up before a plant or hospital unit switches to it.

How the DuPont schedule works

DuPont schedule: a four-crew, 12-hour rotating shift pattern that repeats every 28 days. Each crew works 14 shifts per cycle, 7 on days and 7 on nights, and has 14 days off, including one block of 7 consecutive days.

One crew is on duty at any moment. Over a 24-hour day, two crews work: one on the day shift (for example 7 AM to 7 PM) and one on the night shift (7 PM to 7 AM). The other two crews are off. Each crew runs the same 28-day sequence, started one week apart, so every shift is always covered.

The 28-day sequence for one crew

That is 14 shifts of 12 hours, or 168 hours in 28 days: an average of 42 hours per week. Over a year, each crew works about 182 shifts and has about 183 days off.

The heavy middle week

The averages hide an uneven month. Days 8 to 14 contain six 12-hour shifts in seven days: three day shifts, a single day off, then three night shifts. The flip from days to nights with one day between is the hardest part of the DuPont for most people, and it is where fatigue and call-outs tend to cluster. The last week of the cycle is completely free.

Staffing: how many people you need

Each position that must be filled around the clock needs four people, one per crew. The math: a 24/7 post needs 8,760 hours of coverage a year, and a DuPont worker supplies about 2,190 scheduled hours (42 × 52). 8,760 ÷ 2,190 = 4.

Four people per post leaves no slack. Vacation, sick leave, training and turnover all have to be covered by someone, usually through overtime or a relief pool. Work out your own relief factor from last year's absence data before deciding headcount: add up the scheduled hours lost to PTO, sick leave, training and vacancies per post, and divide by 2,190 to see how many extra people that represents.

Where the DuPont schedule is used

The pattern is named after the DuPont chemical company and is most common in continuous-process work, where shutting down and restarting is expensive or unsafe. Typical users:

• Chemical plants, refineries and other continuous-process manufacturing
• Power generation and utilities
• Food and beverage plants running around the clock
• Mines and other remote sites where long off-blocks let people travel home
• Some hospital units, 911 dispatch centers and security operations

It suits sites where employees value a full week off and where management wants every crew to share nights equally. It suits sites poorly when staff have fixed childcare or second jobs, because the day/night switch changes every week or two.

DuPont schedule pros and cons

The sleep point deserves weight. NIOSH notes that shift work disrupts circadian rhythms and sleep, and that fatigue raises the risk of errors and injuries (NIOSH Science Blog, Shift Work and Sleep). Rotating schedules that move quickly between days and nights are harder on sleep than fixed shifts. If your roles are safety-critical, compare the DuPont with a fixed-shift pattern such as the 2-2-3 work schedule before committing.

DuPont vs other 12-hour schedules

All four patterns need four crews to cover 24/7 with 12-hour shifts. The choice comes down to how off-days are grouped and whether crews rotate between days and nights. See our guides to the Pitman schedule and rotating shift schedules for the other patterns.

Overtime and payroll on a DuPont schedule

Under the Fair Labor Standards Act, non-exempt employees earn overtime for hours over 40 in a fixed workweek (DOL Fact Sheet #23). Each workweek stands alone, so you cannot average a 72-hour week against a zero-hour week (29 CFR 778.104).

If the workweek starts on day 1 of the cycle, one crew's four weeks look like this: 48 hours, 72 hours, 48 hours and 0 hours. That is 8 + 32 + 8 = 48 overtime hours every 28 days, or about 12 overtime hours a week on average. Where your workweek starts and how night shifts that cross midnight are split will change the exact figure, so model it in your payroll system with your real start day.

California adds daily overtime: time and a half for hours over 8 in a workday and double time over 12 (California Labor Commissioner overtime FAQ). Every 12-hour shift therefore carries 4 hours of daily overtime unless the employer has adopted a valid alternative workweek schedule. Most alternative workweeks cap regular hours at 10 per day (California Labor Code §511); the health care wage order allows up to 12. Get California-specific advice before running a DuPont there.

Pay periods and shift differentials

A 28-day cycle never lines up with semi-monthly pay, and it only matches biweekly pay if you accept that alternate paychecks will be much larger than others (one period can contain 120 hours, the next 48). Tell employees this before launch so the swing in take-home pay is not a surprise. See biweekly pay for how pay periods fall across the year.

Because every crew works nights, pay any night differential by the hours actually worked in the night window, not by crew. A clear written rule also settles how the differential feeds into the overtime rate, since the FLSA requires shift differentials to be included in the regular rate.

What to set up before you launch

1. 1Model overtime cost per crew with your real workweek start day and, if relevant, state daily overtime rules.
2. 2Set headcount per post from your absence data, not the bare minimum of four.
3. 3Write a shift-swap policy: who approves, how far ahead, and whether a swap can create overtime.
4. 4Decide how PTO works on a 12-hour schedule. A day of PTO should equal 12 hours, and accrual rates need to match.
5. 5Publish at least two full cycles of the calendar in advance.
6. 6Configure your scheduling or workforce management software to hold the 28-day pattern and flag overtime before the schedule is posted.
7. 7Review after 90 days: overtime per crew, absences in the middle week, and safety incidents by shift.

Frequently asked questions about the DuPont schedule