4 On 4 Off Schedule: the 16-Day Full Cycle

What is the 4 on 4 off schedule?

The 4 on 4 off schedule covers a 24/7 operation with four crews of 12-hour workers. The full version runs on a 16-day cycle: each crew works 4 consecutive day shifts, takes 4 days off, works 4 consecutive night shifts, then takes 4 more days off. Crews are offset by 4 days from each other, so on any given day exactly one crew is on days, one is on nights, and two are resting.

How the 16-day cycle works

Each crew works 8 shifts per 16 days — 96 hours, an average of 42 hours per week, exactly like the DuPont and 2-2-3 patterns. What makes 4 on 4 off feel different is the shape of rest: two 4-day breaks in every cycle. With a single day of annual leave stapled to either end, a 4-day break becomes a 5-day mini-vacation, several times per quarter.

Because the cycle length (16 days) is not a multiple of 7, rest days drift through the week — there is no permanently fixed weekday off, and no weekend guarantee. Workers trade weekend predictability for the two long breaks.

The 8-day simplified variant

Many workplaces advertise "4 on 4 off" but actually run an 8-day version: 4 shifts on, 4 off, with crews permanently fixed to days or nights (like Pitman but in blocks of 4). That variant is simpler to explain and removes the day↔night swing, but the math changes: 4 crews on an 8-day cycle means each crew works half of all days — 182.5 shifts a year, roughly 2,190 hours, far above the 42-hour average. Full 24/7 coverage with a humane workload needs either the 16-day cycle above or a 5th crew. The generator on this page runs the true 16-day, 4-crew version.

Fatigue: the honest picture

Four consecutive 12-hour shifts is a long stretch, and the fourth night of a 4-night run is where fatigue peaks. The mitigations are structural: the day↔night transition always happens across a 4-day break (never a quick turnaround), and the 4 nights are bracketed by 8 days of rest per cycle. Workers consistently rate the pattern better for sleep than fast-rotating schedules, and worse than slow weekly rotations. If your operation is fatigue-critical, rotate days→nights forward through the break — exactly as this pattern does — and avoid overtime call-ins on day 3 and 4 of each block.

Who uses it

Fire and EMS agencies, offshore and maritime crews, security operations, data centers, and manufacturing plants that want longer rest blocks than 2-2-3 provides. It is especially common in the UK and Australia under the name "4 on 4 off," and gaining ground in U.S. 24/7 facilities where recruitment hinges on time off.

Make yours

Set the first day of Crew A's cycle above, generate, and print — or save a PDF per crew. Planning the whole year? The 4 on 4 off schedule 2026 page has all 12 months pre-baked. All five patterns build from the same rotating shift schedule generator on the home page.