Rotating shifts make it hard to answer simple questions: Am I working Thanksgiving? How many weekends do I get this year? Why is my paycheck bigger every other week? This calculator lays any common rotation — 2-2-3, DuPont, 4 on 4 off, 24/48 and more — or a custom pattern of your own onto a calendar, and adds up the averages that matter for pay and planning.
How to use the shift pattern calculator
- Choose a shift pattern, or Custom to type your own.
- Enter the first day of your rotation — any date when you worked day 1 of the pattern.
- Leave hours per shift blank to use the pattern’s usual length, or enter your own.
- Set Show calendar from to the month you want, and how many months to display.
- Read the average weekly hours on the tape, the color-coded calendar, and the monthly totals for the year.
How the rotation is calculated
A rotation is a fixed string of work days and days off that repeats forever. For any date:
The character at that position tells you whether it is a day shift, a night shift, a 24-hour shift or a day off. Dates before the start work too, because the remainder is always taken as a positive number.
Worked example: a 2-2-3 rotation
Pattern DD--DDD--DD--- with 12-hour shifts, starting Monday, October 5, 2026.
The cycle is 14 days with 7 shifts, so it averages 7 × 12 × 7 ÷ 14 = 42 hours a week. Measured in Sunday-to-Saturday weeks, the hours alternate between 36 and 48.
Across 2026 this rotation lands on 182 shifts (2,184 hours), 52 of them on Saturdays or Sundays — every other weekend is a three-day weekend off. October 11, 2026 is day 7 of the cycle, a work day, followed by two days off.
Common rotations compared
| Pattern | Cycle | Shift length | Average week | Shifts per year | Crews for 24/7 |
|---|---|---|---|---|---|
| 2-2-3 (Pitman / Panama) | 14 days | 12 h | 42 h | about 182 | 4 |
| DuPont | 28 days | 12 h | 42 h | about 182 | 4 |
| 4 on, 4 off | 8 days | 12 h | 42 h | about 182 | 4 |
| 3 on, 3 off | 6 days | 12 h | 42 h | about 182 | 4 |
| 5 on, 2 off | 7 days | 8 h | 40 h | about 261 | — |
| 4 on, 3 off (4/10) | 7 days | 10 h | 40 h | about 209 | — |
| 7 on, 7 off | 14 days | 12 h | 42 h | about 182 | 4 |
| 24 on, 48 off | 3 days | 24 h | 56 h | about 122 | 3 |
| 48 on, 96 off | 6 days | 24 h | 56 h | about 122 | 3 |
Twelve-hour 24/7 patterns all average 42 hours because four crews share 168 hours a week. The difference between them is rhythm: how long the stretches of work are, how often you switch between days and nights, and how weekends fall.
What the averages hide
Overtime
The federal overtime rule counts hours in each fixed 168-hour workweek, not over the cycle. A 2-2-3 rotation averages 42 hours, but its workweeks alternate between 36 and 48 hours (or even 24 and 60, depending on the day your workweek starts), so overtime arrives in lumps — 8 hours every other week instead of 2 every week. The overtime calculator works out the pay for a given week.
Night work
Night shifts are counted on the day they start. If your employer pays a premium for nights, the shift differential calculator shows what it adds — including its effect on overtime.
Holidays and time off
Use the calendar to spot which holidays fall on your work days, and the printable calendar to put the holidays themselves on paper. The working days calculator gives the standard Monday–Friday count for comparison.
Frequently asked questions
How many hours a week is a 2-2-3 schedule?
With 12-hour shifts, a 2-2-3 (Pitman or Panama) schedule has 7 shifts every 14 days: 84 hours, or an average of 42 hours a week. Individual workweeks alternate — for example 36 and 48 hours when the workweek starts on Sunday — which is why overtime often appears every other week.
What is the DuPont schedule?
A 28-day rotation of 12-hour shifts: 4 nights on, 3 off, 3 days on, 1 off, 3 nights on, 3 off, 4 days on, then 7 days off. It averages 42 hours a week and gives a full week off once a month.
How do I find out if I work on a certain date?
Enter any date you worked the first day of your pattern, then set the calendar to the month you care about. The calculator counts the days since the start, divides by the cycle length, and uses the remainder to find your place in the pattern.
Can I enter my own pattern?
Yes. Choose Custom and type one letter per day: D for a day shift, N for a night shift, X for a 24-hour shift and a dash for a day off. For example, DDNN---- is two days, two nights and four days off.
How many crews does a 24/7 operation need?
Twelve-hour patterns such as 2-2-3, DuPont and 4-on-4-off need four crews to cover every hour of every day, with each crew starting the same pattern on a different day. A 24-on, 48-off fire service rotation uses three platoons.