4-on-4-off Rotation Schedule Generator
Per-crew summary
4-on-4-off is the simplest of these rotations to describe: work four consecutive shifts, then get four consecutive days off, on an 8-day repeating cycle. There is no block-counting or mid-cycle exception to remember — that simplicity is the entire appeal.
The trade-off is what happens to the calendar. Eight and seven share no common factor, so an 8-day cycle does not line up with the 7-day week — it drifts forward by one weekday every cycle. A crew that starts a work block on a Monday this time will start its next block on a Tuesday, then a Wednesday, and so on, until 56 days pass and the pattern finally lands back on the same weekdays it started on. That is what "weekday alignment: 56 days" means for the fixed variant below.
That drift is the real cost of 4-on-4-off. It is the easiest pattern on this site to explain to a new hire, and the hardest to plan anything recurring around — a crew member who wants a particular weekday evening off for something regular will only land on that same weekday roughly once every 56 days, not once a week.
The fixed variant keeps two crews permanently on days and two permanently on nights, each pair offset four days from the other. The rotating variant instead runs every crew through four days on, four off, four nights on, four off — a 16-day cycle — so nobody stays on permanent nights, but the weekday drift takes twice as long to resolve: 112 days instead of 56. Like every rotation here, 4-on-4-off covers 24/7 with four 12-hour crews averaging 42 hours a week.
Frequently asked questions
Why do my weekends keep moving? Because the 8-day cycle doesn't divide evenly into a 7-day week. Every time the cycle repeats, it starts one weekday later than it did before, so which days end up as your days off keeps shifting.
How long until my schedule repeats on the same weekdays? 56 days for the fixed variant, 112 days for the rotating 16-day variant — both longer than any other rotation on this site, because 8 and 16 share no common factor with 7.
Fixed or rotating — who works nights? Fixed keeps two crews permanently on nights and two permanently on days. Rotating runs every crew through both days and nights within its 16-day cycle, so night work is shared.
Is 4-on-4-off harder to plan around than the others? In one specific way, yes: because its days-off pattern doesn't repeat on the same weekdays for weeks at a time, it's hard to book a recurring weekly commitment against it, even though it's the easiest pattern on this site to explain.