Date & Time
Shift Rotation Duration Calculator
Calculate cycle length, scheduled work and rest days, total hours, complete cycles, and final calendar date. The custom roster calendar distinguishes every on-duty and rest date rather than reducing the pattern to an average.
Days per complete rotation-
Scheduled work days-
Scheduled rest days-
Scheduled work hours-
Complete rotation cycles-
Last date in planning horizon-
Decision view
Dated work-and-rest rotation
Dated work-and-rest rotationEvery horizon day is placed into the repeated on-duty or rest block, preserving the final partial cycle.
Exact scenario comparisonPlanning horizon (days) changes while all other entered assumptions remain constant.
| Planning horizon (days) | Days per complete rotation | Scheduled work days | Scheduled rest days | Scheduled work hours | Complete rotation cycles | Last date in planning horizon |
|---|
Dated roster detail
Rotation cycles and every scheduled day
How to use Shift Rotation Duration Calculator
- Set the start date to day one of a fresh on-duty block.
- Enter contractual on/off blocks and scheduled shift hours.
- Review boundary dates, partial cycles, leave, overtime, handover, and payroll rules against the actual roster.
Calculator guide
Understanding Shift Rotation Duration Calculator
A repeating roster must be counted day by day because a planning horizon rarely ends on a complete work/rest cycle. This calculator begins on the first on-duty day and preserves the exact partial cycle at the end.
Calculation method
How the calculation works
Repeat the entered on-duty and off-duty blocks from the stated start date, count every scheduled work day in the horizon, and multiply shifts by hours per shift. Repeat the entered on-duty block followed by the rest block from the start date, count each state through the exact horizon, and multiply work days by hours per shift.
Roster audit
Check the schedule before publishing it
Correct cycle arithmetic can still conflict with real workplace constraints.
Worked situations
Practical examples
- A four-on/four-off roster repeats every eight calendar days.
- A 90-day horizon contains complete rotations plus the first days of another cycle.
- Twelve scheduled hours multiplied by exact work-day count produces planned hours without averaging.
Better inputs
Useful tips
- Confirm whether the roster starts with work or rest before entering the date.
- Keep unpaid breaks and handover outside shift hours unless the schedule treats them as paid time.
- Export the dated roster and mark local exceptions separately.
Before relying on the result
Limitations and common mistakes
- The pattern is deterministic and does not add holidays, swaps, sickness, leave, training, overtime, or standby.
- Daylight-saving changes, payroll thresholds, fatigue rules, split shifts, and rotating start times are excluded.
- A scheduled work day does not prove hours actually worked.
Reference
Key terms
- Rotation cycle
- One complete on-duty block plus one rest block.
- Partial cycle
- Incomplete final rotation inside the entered horizon.
- Work day
- Calendar date positioned inside the on-duty part of the pattern.
- Scheduled hours
- Work-day count multiplied by entered hours per shift.
Important note
Calculated directly from the entered values using the displayed formula and rounding settings.
Frequently asked questions
Why can work days differ from the on-duty fraction times the horizon?
The start position and partial final cycle affect the exact count.
Does the end date include the first day?
Yes. The horizon counts the entered start as day one.
Can the rotation begin on a rest day?
Not directly; shift the start date back to the first on-duty day of the relevant cycle.
Does this calculate overtime?
No. It reports scheduled days and hours only.