Calculate container Free Time and estimated DEM/DET costs

Contract CSV to invoice review

1. Contract inputsEnter identifiers, DEM/DET/Combined, start/end events and dates, Free Time, day/holiday rules, currency and rate tiers. Reuse local contract presets and revisions; confirm applicability before applying them.
2. Batch calculationReview row errors, estimated LFDs, costs and delay scenarios. A carrier-confirmed LFD entered by the user is shown separately from the calculated estimate.
3. Invoice CSV and correctionsChoose UTF-8 or CP949, check dates and column mappings, then correct confirmed source fields. Unmatched or ambiguous contracts remain unresolved while valid rows continue.
4. Invoice and document reviewCompare partial periods, rate tiers and amounts; flag possible overlaps and missing periods. Keep taxes, fees, discounts and Credit/Debit Notes separate. Netting requires clear references and explicit user confirmation.
5. Work and handoverReview risks, due dates, status and notes. Export CSV, browser print/PDF, all-day ICS and local work JSON. Reopening validates inputs and recalculates; saved results are not trusted.

Fictitious sample: cost and invoice difference

The sample uses a fixed reference date of 2026-10-04, not current carrier tariffs. For DEM from 2026-10-01 to 2026-10-10, both endpoints included, 5 Calendar Days free, and rates of USD10/day for excess days 1–3 and USD20/day thereafter, the estimated LFD is 2026-10-05 and the cost is USD70. These example rules charge every calendar day.

The separate DET sample costs USD30. Expected DEM + DET is USD100; entered base-charge invoice items are USD80 + USD30 = USD110, a USD10 difference. Taxes and other document components are outside this comparison. This is a review signal, not proof of an invoice error or refund.

Terms and dates

DEM (Demurrage) generally concerns a container remaining at a terminal; DET (Detention) generally concerns equipment held outside it. Combined uses one stated scope. Free Time is the agreed free period. LFD is the last free date under the stated rules: an estimate here is distinct from a carrier-confirmed date and local cutoff time.

The calculator processes contract, invoice and note contents in browser memory, without sending them to the server or saving them in browser storage. Existing anonymous usage counts are separate. Files you explicitly save can contain unencrypted source data and notes; review them before sharing.

Confirm the start event, endpoint inclusion, Calendar/Working Day rules, holidays, tariff basis and currency. Missing essentials block comparison. Different currencies are not converted or summed together. No live tracking, automatic alerts, email submission or dispute filing is provided. Public PDF research does not establish compatibility with a carrier’s actual CSV or contract.

Service-feature description checked on 2026-10-26. This is not a tariff verification or effective date.