A 12-hour shift schedule covers a day with two shifts instead of three, which halves the number of handovers and gives every crew far more days off, at the price of longer days. The patterns that rotate 12 hour shifts are few and well known: the 2-2-3 and its Pitman and Panama versions, the DuPont with its week of nights and its week off, and the 4 on 4 off. All of them cover the clock with four crews. This page sets out how each rotates, what the dupont shift work schedule does differently, and why a 3 crew 12-hour shift schedule 7 days a week, which managers keep proposing, is a 56-hour week with a name.
The four-crew patterns
The 2-2-3 works two on, two off, three on, two off, two on, three off across a fortnight, with day and night crews swapping every two or four weeks; every other weekend is free. The 4 on 4 off works four days then four off, drifting through the week so every crew sees every weekend off in turn. The DuPont runs a 28-day cycle: four nights, three off, three days, one off, three nights, three off, four days, then seven days off, so that every crew gets a full week off each month at the cost of a week of nights. All three average 42 hours a week on 12-hour shifts and all three take four crews to cover twenty-four hours every day.
The DuPont shift work schedule
The DuPont is the 12-hour rotation for operations whose crews want a real week off rather than long weekends. Its 28 days run: four night shifts, three days off, three day shifts, one day off, three night shifts, three days off, four day shifts, seven days off. Fourteen shifts in 28 days, 168 hours, 42 a week on average, the same as the 2-2-3, but bunched: a 48-hour week, a 36, a 48, a 36, and the seven days off landing every fourth week. It is harder on sleep than the Panama, because the crew rotates between days and nights within the cycle rather than in blocks, and it suits crews that value the week off more than the steady weekends.
Why three crews do not work
Twenty-four hours a day, seven days a week is 168 hours of coverage; on 12-hour shifts that is fourteen shifts a week. Three crews sharing fourteen shifts work 4.67 shifts each, 56 hours a week, every week, with no pattern that gives anyone a real stretch off. A 3 crew 12-hour shift schedule 7 days a week is therefore not a schedule but a headcount shortfall, and the sixteen hours over forty each person works every week is overtime under the federal Fair Labor Standards Act. The rotating schedule generator on this site returns crews needed as a division, twenty-four over the shift length times the cycle over the days worked, and on 12-hour shifts at half the days it returns four every time.
Questions people ask about 12 hour shift schedule
How many hours a week is a 12 hour shift schedule?
An average of 42 on the 2-2-3, the DuPont and the 4 on 4 off, made of alternating 36-hour and 48-hour weeks. Three crews covering the clock would each work 56.
Which 12-hour pattern is easiest on sleep?
The ones that keep a crew on days or nights for longer blocks: the Panama with its 28-day swap, or fixed day and night crews on a 2-2-3. The DuPont, which turns between days and nights inside its cycle, is the hardest.
Are 12-hour shifts legal?
Federal law sets no maximum shift length for adults and requires overtime on hours over forty in the workweek. Some states add daily overtime over eight hours unless an alternative workweek is adopted, and healthcare and transport have sector rules.