4-on-4-off Shift Schedule: How the 8-Day Cycle Works

The numbers describe consecutive blocks of work days and days off. From the beginning of the cycle, the sequence is:

4 work → 4 off → repeat

This creates an eight-day cycle with four work days and four rest days. Unlike a normal week, the cycle does not restart every Monday.

The repeating eight-day pattern

The simplest way to understand the schedule is to number the cycle days rather than group them into calendar weeks.

Cycle day	1	2	3	4	5	6	7	8
Status	Work	Work	Work	Work	Off	Off	Off	Off

After cycle day eight, the sequence returns to cycle day one. You need one confirmed start date to place every future work and rest block on a calendar.

Why the weekdays keep changing

An eight-day rotation is one day longer than a seven-day week. That means each new work block begins one weekday later than the previous one.

This example begins its first work block on a Monday:

Cycle	Four-day work block	Four-day rest block
1	Monday to Thursday	Friday to Monday
2	Tuesday to Friday	Saturday to Tuesday
3	Wednesday to Saturday	Sunday to Wednesday

The movement is expected; it is not a calendar error. After seven complete cycles—56 days—the work block begins on the same weekday again.

That weekday movement is the main difference from a 2-2-3 shift schedule, whose work-and-rest sequence covers exactly 14 days and therefore lines up with the same weekdays each time it repeats.

What the pattern does not tell you

“4-on-4-off” describes only the work-and-rest sequence. It does not tell you:

1. The shift length or times. A roster may use 12-hour shifts, but the name does not guarantee it.
2. Whether you work days or nights. The day-and-night rotation is a separate part of the roster.
3. Where your crew begins. Another team may follow the same pattern from a different cycle day.
4. How pay or overtime is calculated. Calendar-week hours vary as the eight-day cycle moves across weekdays.
5. Which exceptions apply. Leave, swaps, training, overtime, and holidays can override the base pattern.

What to confirm before putting it in a calendar

Start with a roster or date you know is correct, then confirm:

• the first work day in your eight-day cycle;
• the real start and end time for each shift;
• whether the four-work block is made of day shifts, night shifts, or another sequence;
• your crew or team position; and
• any already-approved changes to the repeating pattern.

If the anchor date is wrong, every future block will also be wrong. Confirming it once is more reliable than trying to reconstruct the pattern from memory each month.

A practical way to track it on iPhone

Create the shift types you actually work, place four work days followed by four days off, and repeat that eight-day sequence forward from a confirmed date. Keep one-off changes separate from the base rotation so a shift swap does not alter every future cycle.

A note about long shifts and recovery

A calendar can show when you are scheduled, but it cannot decide whether a roster is safe for a particular person or workplace. The Canadian Centre for Occupational Health and Safety explains that shift length, rest, workload, rotation, and individual circumstances all matter. The UK Health and Safety Executive also recommends assessing long shifts and allowing adequate recovery. Follow your confirmed workplace roster and the guidance that applies to your job.