Quick answer
The DuPont schedule is a 28-day rotation of 12-hour shifts across four teams. A common version runs 4 nights, 3 off, 3 days, 1 off, 3 nights, 3 off, 4 days, then 7 straight days off. It averages 42 hours a week and mixes day and night shifts inside the same month, which makes it the hardest common rotation to track by hand. Describe it once and subscribe to a calendar link instead.
The DuPont schedule covers 24/7 operations with four teams working 12-hour shifts through a 28-day cycle. Born at the DuPont chemical company in the 1950s, it is still the default in plants, refineries, and utilities. One feature explains its survival: every cycle ends with 7 consecutive days off.
The 28-day pattern
The common sequence: 4 nights, 3 off, 3 days, 1 off, 3 nights, 3 off, 4 days, then 7 straight days off.
Counted by calendar week, the hours run 48, 72, 48, 0. That 72-hour week is DuPont's famous catch, and the zero week is its famous reward. The average is 42 hours, and sites vary the exact sequence, but the signature parts are constant: 12-hour shifts, day and night blocks mixed within the cycle, and the full week off.
The trade
The draw is the 7-day break. Once every 4 weeks, a real vacation-length stretch without using leave. Shift workers plan trips around it.
The cost is the whiplash. DuPont switches between night blocks and day blocks with as little as one day off between them. Sleep never settles. Of the common 12-hour rotations, DuPont is the one sleep researchers like least, and most crews accept it specifically for the week off.
Why tracking it by hand fails
A Pitman schedule is awkward to put in a calendar. DuPont is worse, for three reasons:
- The cycle is 28 days, so a weekly repeat rule is useless.
- Half the blocks are overnights, where a shift starting 7pm Tuesday ends 7am Wednesday. Hand-typed versions reliably get the end date wrong.
- Days and nights interleave, so copy-pasting last week's events produces wrong clock times.
The way out is to stop treating shifts as things you type. Describe the rotation once in plain words, with the cycle's anchor date, and let the shift calendar maker build months of events in one pass. The DuPont preset is tappable, or start from the ready-made DuPont schedule template: edit the times and start date, check the preview against the posted roster, publish.
The output is a calendar link, not a file. Subscribe on the phone and the whole cycle is there, overnights ending on the correct mornings. A spouse subscribes to the same link and sees the 7-day break coming without asking.
If your site runs a variant
Plenty of sites run modified DuPonts: different block orders, 8-hour hybrid versions, or an extra off day. The approach holds. Describe what the roster actually does, week by week, in plain words. The generated preview either matches the posted schedule or it tells you which sentence to fix.