Rotating Shift Calendar
4-on-4-off, panama, dupont and custom shift rotations.
Written and maintained by Paul Clark, Redmoon Software · Rules last verified
These calculators are for informational purposes only and do not constitute legal, financial, or professional advice.
How the Rotating Shift Calendar works
The Rotating Shift Calendar projects a shift pattern forward from a start date and tells you which days are worked. Pick the rotation, set how many days to project, and it lays out the on and off days along with the totals that matter for rostering: shifts worked, days off, and the average weekly hours the pattern implies.
Six named rotations are built in plus a custom option. The simple ones — 4 on / 4 off, 2 on / 2 off, 5 on / 2 off, 6 on / 3 off — are single on-off blocks that repeat. The two industrial patterns are more interesting. <strong>Panama</strong> is a 2-2-3 rotation on a fourteen-day cycle: two on, two off, three on, two off, two on, three off, which delivers every other weekend off and averages 42 hours a week on twelve-hour shifts. <strong>DuPont</strong> runs a twenty-eight-day cycle ending in a seven-day break, also averaging 42 hours, and is common in continuous-process plants. Custom takes any on/off pair you like.
The averages assume twelve-hour shifts, which is the norm for the continuous patterns but not for the five-on-two-off office pattern — read that figure as an indication rather than a payroll input. What the calculator does not model is the day/night alternation inside a rotation. Panama and DuPont both cycle crews between day and night blocks, and the fatigue-management rules that govern how fast a crew may rotate are set by regulation and by agreement, not by arithmetic. This projects which days are worked; whether a given rotation is lawful and safe for your site is a separate question.
Worked example
A crew starts a Panama rotation on Monday, 1 June 2026. The calculator shows two on, two off, three on, two off, two on, three off — then the cycle repeats. Across the first 28 days that is 14 shifts worked and 14 days off, averaging 42 hours a week at twelve-hour shifts. Switch to DuPont over the same 28 days and the shift count is identical, but the distribution is not: the DuPont cycle ends with a full seven days off, which is the trade-off it exists to deliver.
Frequently asked questions
What is the Panama pattern?
A 2-2-3 rotation on a fourteen-day cycle: two days on, two off, three on, two off, two on, three off. Its appeal is that it gives every other weekend off as a three-day break while keeping a continuous operation covered, and on twelve-hour shifts it averages 42 hours a week. It is one of the most widely used patterns in manufacturing, emergency services and security.
How does DuPont differ?
DuPont runs a twenty-eight-day cycle and ends it with seven consecutive days off, which is its defining feature. Over the full cycle it works out to the same 42-hour average as Panama, so the choice between them is about how the time off is distributed — frequent short breaks versus a long one — rather than about total hours.
Does it account for day and night rotation?
No. Both Panama and DuPont alternate crews between day and night blocks, and this calculator marks a day as worked without saying which shift it is. Rotation speed and direction are governed by fatigue-management rules and often by collective agreement, and they matter for safety rather than for arithmetic — take those from your own scheme.
Do public holidays interrupt the rotation?
No. The pattern continues through them, which is how continuous-operation rosters actually work. Whether a holiday worked attracts different pay is a separate question set by your agreement, and the calculator does not model it.
What this calculator does not do
A limitation you know about costs far less than one you find after the deadline. These are the specific things this tool cannot work out for you.
- Named rotations such as Panama and DuPont have common definitions but crews run local variants. Check the pattern against your own roster before relying on it.
- Public holidays do not interrupt a rotation. The pattern continues through them.