Demurrage & Detention Free-Time Calculator
Calculate the last free day from carrier- or terminal-confirmed calendar, weekend and excluded-date rules without estimating charges. Inputs stay in your browser.
The planner counts from the first free-time date using the calendar or business-day rule entered. It does not estimate charges or decide whether an invoice is reasonable. Review note: Confirm the governing tariff or service-contract clock.
Context matters.
- Demurrage, detention, storage and per-diem terms can use different anchors and calendars.
- Cargo availability, terminal access, empty-return appointments, waivers and invoice disputes require the live carrier or terminal process.
Sources & scope
The calculation guide and this source trail show what the result means, where the rule came from and when it was last reviewed. This is source-and-calculation QA, not a claim of medical, legal, tax or other professional review; time-sensitive decisions still belong with the linked authority.
A visible path from input to answer.
Calculate the last free day from carrier- or terminal-confirmed calendar, weekend and excluded-date rules without estimating charges. The page keeps the calculation scope and its limits beside the result so the output can be checked, copied or revisited.
- Read the record. The calculator uses Container clock, First counted free-time date, Free days granted, Counting basis and Weekend pattern and 3 additional fields supplied in the form.
- Apply the scope. It applies the Ocean-carrier and terminal free-time arithmetic — tariff, service contract and invoice record control reference and the explicit date, unit and counting conventions shown in the result.
- Expose the checkpoints. Intermediate rows, warnings and timeline events stay visible; the emphasized row identifies the primary checkpoint when one exists.
The planner counts from the first free-time date using the calendar or business-day rule entered. It does not estimate charges or decide whether an invoice is reasonable. Review note: Confirm the governing tariff or service-contract clock.
- Last free dayAug 29, 2026
- Rule verificationNot confirmed
Calculation purpose: Calculate the last free day from carrier- or terminal-confirmed calendar, weekend and excluded-date rules without estimating charges. This is a high-sensitivity reference output; the linked authority or qualified professional controls the final decision.
Calendar inputs use plain year-month-day semantics. Leap days, month ends, date-pair order and unsupported dates are checked before the result is shown.
Rule set 1.1.0 · Last reviewed 2026-08-22 · Next review due 2027-02-22. The source panel below contains the linked evidence.
What to know before using the result.
What is the difference between demurrage and detention?
Demurrage commonly concerns terminal time, while detention commonly concerns equipment outside the terminal, but the carrier's tariff or service contract controls the labels and clocks.
Are weekends and holidays always free days?
No. Some clocks use calendar days and others exclude defined days. Enter the exact counting basis and exclusions from the governing record.
Does this calculator estimate charges?
No. It finds a last free day from entered rules; tiered rates, currency, caps and invoice disputes stay outside the result.