To check rest between shifts, put each person’s shifts in time order and subtract the previous shift’s finish from the next shift’s start. Keep the full dates as well as the times. The result is observed time off between duties; it does not tell you how much someone slept.
Prepare the rows
- Use a staff reference rather than a name, with the same reference across sites.
- Keep one row per shift, with a start date and time, an end date and time, and the site.
- Confirm the time zone and include shifts immediately before the week being checked.
- Keep recorded work separate from alternative or duplicate versions of the same shift.
A worked Excel example
In this synthetic example, column A is the worker reference, B is the full start date and time, and C is the full finish date and time. Sort by worker and then start time.
| A: Worker | B: Start | C: Finish | D: Gap (hours) |
|---|---|---|---|
| W-001 | 19 Oct 2026 14:00 | 19 Oct 2026 22:00 | Not known: preceding shift missing |
| W-001 | 20 Oct 2026 07:00 | 20 Oct 2026 15:00 | 9 |
| W-002 | 19 Oct 2026 09:00 | 19 Oct 2026 17:00 | Not known: different worker |
First find and resolve duplicates and overlapping duties for each worker, including a long duty that contains another duty. The immediately preceding row may not be the last duty to finish when shifts overlap.
Once the duties do not overlap, =(B3-C2)*24 gives the gap in hours for a row whose preceding row belongs to the same worker. Only use it after checking that A3 and A2 identify the same person. Leave the first shift for each worker as unknown unless the preceding shift is available.
A finish at 22:00 on Monday followed by a start at 07:00 on Tuesday gives 9 hours between shifts. RosterWise flags gaps under its 11-hour daily-rest reference for review. A negative gap indicates overlapping duties or a data problem that needs investigation.
Where the spreadsheet can mislead
Excel date-time cells do not carry a time zone. Across a clock change, convert times with a method that handles the relevant zone; ordinary subtraction of local wall times can misstate the elapsed gap. Do not quietly assume a missing finish date, shift-code meaning or previous shift.
A gap above a reference does not establish that the whole pattern needs no further review. Night work, long duties and runs of days need their own checks. Roster records also do not establish sleep, travel time or other work.
Using RosterWise
Upload the Excel workbook, CSV or other delimited roster file, check its interpretation and answer any time-zone or shift-code questions before analysis. Open a finding to see the shifts behind it. Missing earlier work remains missing evidence.
See how the review works, the references and limits of the checks, and what roster data can tell you.