Passage Clock

UTC + Home + Destination, plus "how many days have I been out here?"

Designed for passages: UTC as the anchor, fixed home/destination clocks, and a passage timer. Works offline once loaded (PWA cached).

No accounts. Runs locally. No nonsense.

Setup

Set this once at the dock - then forget it.
Pick a common port (optional)
This fills the destination timezone for you.
Ship time
Useful if the crew runs "ship's time" and bumps it occasionally.
Quick start
  • Set Home and Destination.
  • Hit Start journey when you leave.
  • Use Reset if you're starting over.
How it works
  • UTC is always shown and is the safest reference offshore.
  • Home and Dest are timezone displays only (no GPS needed).
  • Elapsed is stable while this page is open; after reload it falls back to device time.
  • Your settings are saved locally on the device (Export/Import available).
  • Offline: ads may not load; clocks still run.
Dashboard
Hide setup once you've started the journey.

Clocks

Diagnostics
Link: Checking link... Clock: Checking clock... Journey: not started PWA: checking...
UTC Anchor
--:--:--
---
HOME -
--:--:--
---
DEST -
--:--:--
---

Passage

Elapsed
-
Elapsed continues while this page remains open.
Saved locally. After reload it resumes from where you left off. Big device clock changes can affect absolute timestamps.
Started (UTC)
-
Stored locally on your device (no account, no server).

What this tool does

Shows UTC, your fixed Home port, your Destination port, and a running passage timer on a single offline-ready dashboard. It's designed for boats that need to keep multiple reference clocks straight without digging through chartplotter menus.

You can also enable "ship's time" - a manual offset clock crews often slide during long passages.

How it works

Common use cases

FAQ

Does this work offline?

Yes. Once loaded, the PWA cache keeps everything available without a connection so long passages stay covered.

How accurate is the elapsed timer?

It uses your device clock. Large manual time changes can skew it, so avoid changing system time mid-passage.

Can I pre-load destination presets?

The preset dropdown ships with popular bluewater ports. Future releases will add more; for now you can type any timezone manually.

What if my device reboots?

The journey data is saved locally, so reopening the tool resumes from where you left off.

Why do I see "-" on the clocks?

Until you choose Home and Destination, the app leaves placeholders. Fill both fields to unlock the full display.

Is there an alarm?

Not yet. Passage Clock focuses on reference clocks and elapsed time; pair it with Interval Timer for alarms.

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