Key takeaways
- Identify the event behind each boundary before calculating its duration.
- Preserve dates and time bases when periods cross midnight.
- Link exclusions to both factual support and the adopted contractual treatment.
- Distinguish a missing record from a disagreement about its meaning.
- Make the calculation reproducible without implying that reproducibility proves entitlement.
Build the account from identifiable events
Gard's NOR guidance discusses the contractual significance of a valid notice to laytime commencement. That context explains why an account's opening input deserves careful review. Check the current text and obtain advice on the relevant commencement mechanism rather than importing a standard assumption.
The same discipline applies throughout the account. An interval needs a defined start and end. Each boundary should identify the event and source relied on. A spreadsheet row labelled “delay” is incomplete if the reviewer cannot tell what began or ended at its boundaries.
The source may be a contemporaneous operational record, communication or subsequently clarified statement. Preserve its status. A later reconstruction can be useful, but it should not be presented as an original event record. The decision-maker needs to understand the quality and limits of the supporting evidence.
Begin with the material intervals. Exhaustive document indexing is less useful than ensuring that the inputs driving the account are traceable and intelligible.
Preserve the full time context
An isolated clock time cannot establish the duration of an interval crossing a date boundary. The account needs the relevant dates and a consistent understood time basis. Keep the original source values visible and explain any conversion used in the working calculation.
Do not infer that every document uses the same convention. Vessel, agent and internal records may need clarification. If the time basis is missing or inconsistent, ask the responsible source before relying on a precise duration.
The reviewer should also distinguish a recorded event from the time a message reporting it was sent. A later email may describe an earlier occurrence. Using the email timestamp as the event time can produce an apparently exact but unsupported interval.
Where a source rounds its times, preserve that limitation. Do not add unwarranted precision in the spreadsheet. The arithmetic can be exact relative to its inputs while the inputs themselves remain approximate or disputed.
Worked fictional interval across midnight
This ILLUSTRATIVE example uses fictional events on a single fixed time basis, with no clock change. The review interval begins at 22:00 on Day A and ends at 10:00 on Day B. An exclusion is expressly assumed to apply from 02:00 to 05:00 on Day B.
| Component | Calculation | Result |
|---|---|---|
| Before midnight | 24:00 − 22:00 | 2 hours |
| After midnight | 10:00 − 00:00 | 10 hours |
| Elapsed interval | 2 + 10 | 12 hours |
| Assumed excluded period | 05:00 − 02:00 | 3 hours |
| Counted interval | 12 − 3 | 9 hours |
The calendar-aware calculation confirms the elapsed interval rather than subtracting the clock readings as though they occurred on the same day. The example assumes the exclusion's factual boundaries and contractual applicability solely for arithmetic. It calculates no allowance balance, demurrage or payment entitlement.
The supporting package in a live fixture would need evidence for both interval boundaries and the exclusion. A neat table does not replace that evidence. The reviewer should be able to move from each material input to the record that explains it.
Link the fact and the counting assumption separately
A record can establish that an operation stopped without establishing that the time is excluded. The contractual analysis determines the treatment on the actual wording and circumstances. Keep that reasoning distinguishable from the event evidence.
Use a source-to-decision note for each material disputed interval. State the factual proposition, its supporting record, the adopted treatment and the unresolved question. This prevents an exclusion from appearing as an unexplained negative number in the account.
If the reason for the interruption is disputed, identify the alternative factual accounts. If the facts are agreed but the rule is disputed, identify the competing treatments. These situations may lead to different requests for evidence or advice.
The distinction also helps explain changes. New evidence may alter an interval boundary without changing the counting rule. A new interpretation may change treatment while leaving the event sequence untouched. The account should show which kind of development caused the result to move.
Use an evidence matrix that supports reproduction
| Account input | Evidence question | Decision question |
|---|---|---|
| Commencement boundary | Which event and communication are relied on? | What commencement mechanism applies? |
| Interruption start | What stopped, and when? | Is the period potentially relevant to an exclusion? |
| Interruption end | What event establishes the changed condition? | When does the adopted treatment change? |
| Completion boundary | Which completion event is recorded? | Does it match the contractual endpoint being analysed? |
| Time conversion | What basis did the source use? | Is the conversion appropriate for this calculation? |
| Qualification | What remains approximate or disputed? | How should the account express that uncertainty? |
A reviewer should be able to reproduce the arithmetic using the stated inputs without inventing missing information. If a result requires a hidden assumption, make it explicit or obtain the missing answer. The aim is an account whose logic can be examined, not simply a file whose formulas produce a total.
Handle gaps without manufacturing certainty
Where evidence is missing, identify the smallest useful clarification. The desk may need the date associated with a time, the meaning of an event label or confirmation of a cause transition. A focused request is easier for the source to answer than a general demand for more documents.
If the gap remains, the principal may consider an appropriately authorised provisional analysis. It should explain the assumed input and the decision affected. Do not silently choose the value most favourable to the presenting party and label it factual.
A sensitivity comparison can be useful where the unresolved boundary is commercially material, but it needs clearly defined alternatives and checked arithmetic. It should not imply that unsupported scenarios are evidence. Their role is to show how a stated uncertainty affects the account.
Once clarification arrives, update both the calculation and the explanation. Preserving an outdated qualification after the evidence is resolved can be as confusing as prematurely removing one.
Common mistakes
Subtracting clock readings without dates can distort an interval across midnight. Another mistake is using a message timestamp in place of the event it reports. Preserve the full source context before calculating.
Do not treat a stoppage record as automatic authority for an exclusion. Avoid adding precision unsupported by the source. Finally, ensure that the account's explanation identifies the assumptions actually used; a calculation is not reproducible if its decisive input exists only in the preparer's memory.
Where Zeaclub fits
Zeaclub provides a multi-party shared workspace for owners, charterers, brokers and port agents.
Zeaclub offers digitalised procedures across the voyage workflow.
Explore Zeaclub
Educational information only; not legal, financial or trading advice. Contract wording and applicable rules control. Verify current requirements and obtain qualified advice before acting.
Frequently asked questions
Is the statement of facts enough for every interval?
It may supply relevant inputs, but its scope and qualifications need review. Material gaps or conflicts can require supporting communications or clarification from the responsible source. Do not assume completeness from the document title.
Why retain dates when the account displays only hours?
Dates help establish the correct sequence and duration, especially across midnight. The presentation can be concise, but the underlying calculation should retain the information needed to reproduce the interval accurately.
Does proof of an interruption prove an exclusion?
No. The event evidence and contractual treatment are separate questions. Identify the relevant wording and obtain appropriate advice before applying the proposed treatment to the established facts.
What should the reviewer do with an approximate event time?
Preserve the qualification and assess its significance. Seek clarification where material. If an authorised provisional input is used, label it clearly rather than converting an estimate into an apparently confirmed fact.