Key takeaways
- Laytime is contractual time for cargo operations, defined in the charter party.
- Exceed it and demurrage accrues; beat it and despatch may be earned.
- The calculation runs on evidence: notices of readiness, statements of facts, weather and exception clauses.
How laytime calculations work
The charter party defines when laytime starts (typically after a valid notice of readiness), how it counts (weather working days, Saturdays and holidays included or excepted), and what interrupts it. The statement of facts from the port records every event: berthing, gangs on board, stoppages, completion. The laytime calculation applies the clauses to those events and produces a demurrage or despatch figure.
Disputes are common because the inputs are messy: conflicting statements of facts, arguable notice validity, exception clauses read differently by owner and charterer. Desks that standardize the calculation, keep the evidence organized, and submit claims within contractual time bars collect what the contract provides; late or poorly evidenced claims simply expire.
Why laytime discipline matters
- Demurrage claims are won or lost on calculation quality and evidence, not negotiation volume.
- Time bars make speed an economic requirement: late claims are worthless.
- Laytime data shows which ports and terminals systematically consume the allowance.
Laytime in a live chartering operation
A bulk charterer's desk runs every voyage through a standard laytime calculation as documents arrive, not months later. Claims go out inside the time bar with the statement of facts attached, counterclaims are answered from organized evidence, and recurring congestion at one terminal shows up in the data and reprices the next fixture.
Frequently asked questions
What is the difference between laytime and demurrage?+
Laytime is the allowed time for cargo operations; demurrage is the agreed compensation paid to the owner when laytime is exceeded. Demurrage in chartering differs from container demurrage, which relates to container use at terminals.
What is a notice of readiness?+
The master's formal notice that the vessel has arrived and is ready to load or discharge. A valid notice usually triggers the start of laytime, which is why its timing and validity are so often disputed.
Written and reviewed by the InfoSun operations team. Last updated September 9, 2026.