Audit Adjacent Shift Rest Gaps Using Dates and Explicit Clock Offsets — Free
Clock times alone can hide an overnight turnaround or an offset change. Put dated shift instants on one strip and keep the smallest adjacent rest gap visible before asking a workplace representative about the actual schedule.
The proof surface
Roster-cycle counters tally repeating workdays. This strip measures actual gaps between one person's ordered shifts using explicit offsets. It checks chronology and real calendar dates; a reader-supplied discussion mark never becomes an inferred labor-law requirement.
InputShift code | start YYYY-MM-DDTHH:MM±HH:MM | end YYYY-MM-DDTHH:MM±HH:MM; supplied rest-gap discussion mark (hours)
Rare deviceRoster-cycle counters tally repeating workdays. This strip measures actual gaps between one person's ordered shifts using explicit offsets. It checks chronology and real calendar dates; a reader-supplied discussion mark never becomes an inferred labor-law requirement.
Output artifactSmallest adjacent elapsed rest gap with row-by-row context
Cost$0 local calculation · no card, paid key, subscription or signup · proposed filing price is not for sale
Sample, not your facts: Illustrative inputs: First day | 2026-10-01T09:00+00:00 | 2026-10-01T17:00+00:00; Second day | 2026-10-02T09:00+00:00 | 2026-10-02T17:00+00:00. Supplied rest-gap discussion mark (hours) = 11. Smallest adjacent elapsed rest gap: 16 hours minimum observed gap. All records are invented.
Before using the rest-gap strip
Use observed or confirmed shift start and end instants, including the numerical UTC offset that applied at each instant. Do not enter a time-zone name and expect daylight-saving rules to be looked up. The accepted format has minute precision, years 1900–2200, and offsets no greater than fourteen hours. Dates such as February 30 are rejected rather than normalized into March. Rows must be in increasing start order, each end must be later than its start, and shifts cannot overlap in this single-person model. At least two shifts are needed for a gap. On-call arrangements, split shifts, contractual definitions and legal exceptions are deliberately not inferred. Anonymous shift codes and clocks are sufficient; employer and worker identity need not be shared.
Why the flat version breaks
Dropping dates at midnight
22:00 to 06:00 needs the next day's date to represent eight hours, not a negative clock subtraction. This tool requires complete instants at both endpoints. It also rejects an impossible calendar date so a typographical error cannot quietly turn into a different day and a misleading rest gap.
Applying the browser's time zone
The browser may be in a different zone from the workplace. Explicit endpoint offsets make the calculation independent of that browser setting. The app does not infer regional daylight-saving transitions; supplying the wrong offset can still produce a wrong gap, so verify it against the schedule.
Equating the gap with sleep or compliance
Rest between shift endpoints is not the same as sleep, and a user-entered mark is not a verified statute. Commute and other obligations reduce the time available for rest. Keep those distinctions visible and ask a qualified workplace adviser about the actual policy and individual circumstances.
How to work the rest-gap strip
Confirm the actual time convention
Obtain the offset for both endpoints from a reliable schedule or calendar. Across a clock change, the same local hour can represent different instants. An offset is part of the observation, not a convenience the app can guess. If the source omits dates or offsets, ask the scheduler to clarify before treating a calculated gap as evidence.
Enter one person's ordered nonoverlapping shifts
Keep each start and end as a complete dated instant. Provide at least two shifts in source order and check that the first has a positive duration. Do not combine two workers in one strip or count a separate on-call period as an ordinary shift without a verified convention. The parser retains errors rather than sorting or trimming conflicting observations.
Subtract instants at each adjacent boundary
Convert explicit-offset timestamps to comparable elapsed instants and subtract the previous shift's end from the next start. Keep the first row's prior gap unavailable. The summary is the minimum of observed adjacent gaps. Review marks use strictly less than the supplied hour mark, so a gap exactly at the mark is not flagged in this model.
Raise a schedule question with the right human
Bring the original rota and the gap workings to HR, a union or qualified employment adviser. Ask which rest definition and exceptions apply rather than asserting a breach from this strip. A planned long gap can still contain commute or caring work; the tool measures between-shift elapsed time and cannot certify fatigue management or actual sleep.
What the rest-gap strip separates
Question
Before
Inspect this instead
Dropping dates at midnight
22:00 to 06:00 needs the next day's date to represent eight hours, not a negative clock subtraction. This tool requires complete instants at both endpoints. It also rejects an impossible calendar date so a typographical error cannot quietly turn into a different day and a misleading rest gap.
Enter one person's ordered nonoverlapping shifts
Applying the browser's time zone
The browser may be in a different zone from the workplace. Explicit endpoint offsets make the calculation independent of that browser setting. The app does not infer regional daylight-saving transitions; supplying the wrong offset can still produce a wrong gap, so verify it against the schedule.
Subtract instants at each adjacent boundary
Equating the gap with sleep or compliance
Rest between shift endpoints is not the same as sleep, and a user-entered mark is not a verified statute. Commute and other obligations reduce the time available for rest. Keep those distinctions visible and ask a qualified workplace adviser about the actual policy and individual circumstances.
Raise a schedule question with the right human
This rest-gap strip replaces a manual count or calculation, not source verification or the responsible person’s review.
Run it on the samples, right here
FIRST-LOAD
HYPOTHESIS / PROTOTYPE — checkout unavailable. Calculation is local. A draft is saved automatically in this browser profile when storage is available; Reset to sample clears it. Optional Pro history stores only five summaries and has its own deletion control. State links encode your inputs and can remain in browser history, clipboard or recipients’ records; share only non-sensitive rows. Optional external AI formatting leaves this device. The required site analytics beacon reports page activity; shared URLs contain encoded inputs. Do not treat an encoded URL as private. The calculator has no input-collection endpoint.
Schedule arithmetic only, not fatigue certification or employment-law advice. Verify dated offsets with the scheduler and ask HR, a union representative or qualified employment adviser which rest rules and exceptions apply; this tool does not guarantee safety or compliance.
Data note: The rest-gap strip processes Shift code | start YYYY-MM-DDTHH:MM±HH:MM | end YYYY-MM-DDTHH:MM±HH:MM locally. Starter/sample selection and Run compute in this tab; no input is sent by the calculator. A local draft may be saved; explicit state-link sharing or optional external AI formatting can disclose inputs. Use non-sensitive labels.
Go deeper: the companion app files the same reading as a paper ticker strip
The article demo above runs without limits. The companion app keeps a local history, exports the rows as CSV, prints the rest-gap strip reading, and holds your drafts on this device — one complete free app run; the proposed $4 one-time filing layer is not for sale.
The rest-gap strip answer stays complete for free. The proposed $4 one-time filing layer adds row CSV, print and five local reading summaries, not hidden answers. Checkout is unavailable; the article demo remains unlimited.
Schedule arithmetic only, not fatigue certification or employment-law advice. Verify dated offsets with the scheduler and ask HR, a union representative or qualified employment adviser which rest rules and exceptions apply; this tool does not guarantee safety or compliance.
What this is built on
Method: Convert explicit-offset timestamps to comparable elapsed instants and subtract the previous shift's end from the next start. Keep the first row's prior gap unavailable. The summary is the minimum of observed adjacent gaps. Review marks use strictly less than the supplied hour mark, so a gap exactly at the mark is not flagged in this model.
All sample records, dates, quantities and labels are invented. No outside policy, contract, rate, clock offset, measurement or accessibility standard is represented as verified.
Google’s official pricing documentation, fetched 2026-10-01, says AI Studio is free in available regions. Optional formatting may require a Google account; manual local entry requires none. Limits can change and free-tier content may be used to improve products. Do not send private records.
Before: an overnight turnaround was hidden in clock labels. After: dated, offset-specific shift boundaries expose each actual elapsed gap.
Three worked readings, with different inputs
Sample A — typical inputs
First day | 2026-10-01T09:00+00:00 | 2026-10-01T17:00+00:00
Second day | 2026-10-02T09:00+00:00 | 2026-10-02T17:00+00:00
The first shift ends at 17:00 UTC on October 1; the next starts at 09:00 UTC on October 2. Their elapsed gap is sixteen hours. The first row has no earlier observed shift, so it displays no prior gap instead of pretending a zero rest period. The summary selects the smallest adjacent gap, not a sum of rest hours across different boundaries.
From 22:00 to 06:00 next day is eight elapsed hours, below the supplied eleven-hour discussion mark. The result does not establish a legal breach: the mark is an input and the tool has no jurisdiction, exceptions or contract evidence. Commute, meals, caring duties and actual sleep are outside the gap, so eight hours between shifts is not eight hours asleep.
The second shift begins at the exact instant the first ends, leaving zero elapsed gap. This is accepted as a contiguous boundary and receives a review mark when the supplied requirement is positive. A second start before the first end would be rejected as overlapping single-person shifts, preserving the source rows for correction instead of inventing negative rest or a silent reorder.
Optional AI formatting, never the calculation
Manual entry completes this rest-gap strip for free without signup. If available to you, the free AI Studio interface linked in the sources may format fictional or non-sensitive notes; external access may require an account. No API key or AI call is built into this tool. Free-tier content may be used to improve products. Review each cell and transcribe it to the labeled row schema; do not paste the JSON object into the row box.
Format only these fictional or non-sensitive notes for a rest-gap strip. Return strict JSON shaped as {"rows": [{"label": "string", "cells": ["string", "string"]}], "setting": "string"}. The columns are Shift code | start YYYY-MM-DDTHH:MM±HH:MM | end YYYY-MM-DDTHH:MM±HH:MM; the setting is Supplied rest-gap discussion mark (hours). Keep all supplied strings and quantities exactly; do not calculate, infer missing entries, invent dates or add advice. If any required value is missing, return an empty rows array and ask me for it separately. I will verify every cell against my source and manually transcribe rows using vertical bars before running the local calculator.
An AI response is not executed, fetched or trusted as a result. Missing values remain questions; the strict local parser checks the rows you actually enter.