Key takeaway
An arrival date and a pickup date are insufficient: the applicable start, closure, free-time and end-event rules determine the count.
Identify which clock the record describes
A container archive may retain arrival, availability, appointment and gate events while leaving the free-time convention in a separate agreement. The first review decision is whether those records can reproduce the invoiced period. Do not infer charged days from elapsed calendar time until the governing clock is identified.
The Federal Maritime Commission distinguishes demurrage beyond free time at a terminal from detention for extended use of equipment. Maersk’s public terms also describe separate inside-terminal, outside-terminal and combined arrangements, with rates subject to the applicable tariff or specific agreement. These sources were checked 11 October 2026. Their definitions do not determine a particular invoice’s legal validity or the terms of another carrier.
Reproduce one hypothetical free-time calendar
This invented agreement starts an inside-terminal clock on Tuesday 13 October 2026 at 08:00 local time. It allows three eligible free days, counts only Monday-to-Friday gate-open days, excludes a documented full closure, and counts a charged gate-out day inclusively. These are example assumptions, not a quoted carrier tariff. The terminal closes fully on Wednesday 14 October and the container gates out on Monday 19 October.
Tuesday is free day one, Thursday day two and Friday day three. The closed Wednesday and the weekend are ineligible under the invented agreement. Monday 19 October is the first and only charged day. An illustrative invoice that charges both Friday and Monday has a one-day discrepancy against this stated convention. That discrepancy goes to contract and event review; it is not a finding that a refund is legally required.
| Local date | Example event or condition | Eligibility | Count under invented terms |
|---|---|---|---|
| Tue 13 Oct 2026 | Clock starts; gates open | Eligible | Free day 1 |
| Wed 14 Oct 2026 | Documented full closure | Excluded | No free or charged day |
| Thu 15 Oct 2026 | Gates open | Eligible | Free day 2 |
| Fri 16 Oct 2026 | Gates open | Eligible | Free day 3 |
| Sat 17 / Sun 18 Oct | Weekend | Excluded by example agreement | No free or charged day |
| Mon 19 Oct 2026 | Gates open; full gate-out | Eligible; end day included | Charged day 1 |
Verify the events that change eligibility
Recover the source of the availability/start event and the full gate-out event, including time zone, timestamp meaning and any corrected event history. Vessel arrival alone may not be the contracted start. An appointment request does not prove pickup; an appointment screenshot does not necessarily establish a full terminal closure or a recognized waiver.
Maersk’s US import information describes different start rules across ports, distinctions between full and partial closures, and booking arrangements that can differ from a standard tariff. It also cautions about appointment evidence. Use those observations to ask for the applicable port and booking records, not to apply one public page universally. A few hours of restricted gate access should not silently become a whole excluded day in the ledger.
Attach a rule version rather than a guessed daily rate
The ledger needs carrier, terminal, container scope, movement type, applicable booking or agreement, free-time allowance, eligibility convention, end event and tariff version. Keep invoice quantity and rate as separate fields. This example calculates days only: it has no verified applicable monetary tariff, and a public tariff summary is not sufficient evidence for an actual daily charge.
If a contract uses calendar days, an inclusive arrival day, a different closure policy or a combined free-time period, rerun the ledger under that actual wording. Label alternatives as alternatives. Do not merge inside-terminal days with outside-terminal equipment use merely because both appear on a logistics invoice. Record unresolved terms and assign them to the commercial owner; the arithmetic should not conceal a disagreement about which agreement applies.
Choose the bounded record the archive can support
The hypothetical archive supports a one-charged-day calculation only under its declared rules and full-closure evidence. A real review should preserve the invoice, agreement, original events, rule interpretation and any dispute outcome as separate records. An invoice correction is an observed later event if documented; it should not be generated as a label from the example’s arithmetic.
Inventory can map gate and booking evidence, while Due diligence can define whether a recipient needs calendar reconstruction or only logistics milestones. Commercial disputes, consignee identifiers and restricted terminal feeds need disclosure review before a real sample. Use the synthetic calendar to explain the package first. This guide does not assert current invoice-law requirements, tariff rates, carrier fault, buyer demand or permission to share the source records.