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UTC ↔ local time converter

Maritime operations run on UTC: deck logs, NOR tenders, position fixes, AIS pings, weather routing, port-control reports. But port agents, charterers, and shore staff frequently quote local time. Mistakes here trigger missed arrivals and demurrage disputes.

The converter below uses the IANA timezone database via Intl.DateTimeFormat — DST transitions are applied automatically per the relevant national rule (Europe spring/autumn, Australian / NZ rules, US end-of-DST 2024 still in force, etc.).

Pick a UTC instant and a target port; the "all major ports" table below also shows the same instant at every other top-tonnage port — useful when planning multi-port voyages or fleet-wide scheduling.

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When to use this tool

Pre-arrival NOR tendering (ETAs quoted UTC + local for the agent/terminal), charterparty laytime deadlines (WWD SHINC/SHEX cutoffs are typically local-time), crew-change flight bookings vs. vessel arrival, and coordinating shore-side technical support calls across time zones.

Worked example

Scenario: Vessel notifies ETA Rotterdam 14 Nov 2025 at 08:00 UTC. Charterer NOR deadline is "WWD SHINC 06:00 local at port of arrival".

Convert: 08:00 UTC 14 Nov at Rotterdam (CET, UTC+1 in winter) = 09:00 local. NOR tendered 3 hours after the notional local deadline. Laytime clock is likely to start earlier than intended — confirm the agent's SoF entry.

Regulatory basis

No direct regulation of time conversion — but SOLAS V/28 requires ship's time (bridge clock) to be kept in a documented system, and MLC 2006 A2.3 rest-hours records must be time-zoned correctly. Deck-log entries follow ship's time convention (typically UTC or the current zone time), which must be consistent between the bridge log + engine log + cargo log.

See also