DuPont Schedule: the 28-Day Rotating Shift Pattern

What is the DuPont schedule?

The DuPont schedule is a rotating shift pattern built for operations that never stop. It takes its name from the DuPont chemical plants that popularized it in the 1950s, where reactors run around the clock and someone has to be watching them at 3 a.m. on a Sunday. Four crews share the load, working 12-hour shifts on a 28-day cycle, so the plant is covered every hour of every day while each worker averages 42 hours a week.

How the 28-day cycle works

Every crew follows the same sequence: 4 night shifts → 3 off → 3 day shifts → 1 off → 3 night shifts → 3 off → 4 day shifts → 7 off. The four crews are staggered exactly one week apart, which means coverage never moves: on any given day, one crew is on days, one crew is on nights, and two crews are off. After 28 days the pattern closes on itself and repeats forever.

The arithmetic works out cleanly: 14 shifts per 28 days, 168 hours per cycle, an average of 42 hours per week. Because the Fair Labor Standards Act counts overtime by the workweek rather than by the cycle average, the long weeks in a DuPont cycle can trigger real overtime — worth checking with your payroll team before you adopt it.

The part everyone talks about: the 7-day break

Ask DuPont workers what keeps them on the pattern and you will hear one answer first: the week off. Every 28 days, each crew gets seven consecutive days away — a full vacation-length break thirteen times a year without touching PTO. Veterans describe a second benefit that matters just as much: total predictability. The pattern never changes, so experienced workers can tell you years in advance whether they are working a given birthday or holiday without opening the calendar.

The hard part: the “week from hell”

The same veterans will warn you about the middle of the cycle. The stretch of 3 day shifts, a single day off, then 3 night shifts forces a body clock flip in under 24 hours, and crews consistently call it the roughest week of the rotation. It is the price of the long break, and whether that trade is worth it is genuinely personal — workers with young kids and spouses on standard schedules tend to feel it most, since weekends on shift are built into the pattern.

Who uses it

Chemical and refining plants, paper mills, manufacturers with continuous lines, power stations, and any 24/7 operation that wants deep coverage with built-in recovery time. If your workplace needs two crews resting for every two on duty, the DuPont schedule is the classic answer. Adoption tip from crews that have lived through the switch: publish the calendar at least one full cycle ahead, and decide the overtime rules for the 7-day break before the first cycle starts — the break is the pattern's selling point, and nothing sours it faster than watching it get called in.

Make yours

Scroll up, set the first day of your cycle, and print the calendar — or save it as a PDF and send one to each crew. Comparing patterns? The 2-2-3 schedule trades the long break for shorter weeks and every-other-weekend off, and our rotating shift schedule generator builds both.