Watch Bells
Traditional ship's bells, every half hour

Naval timekeeping · Desktop utility

Watch Bells

Traditional ship's bells for your computer.

A ship's bell divides each four-hour watch into half-hours. One bell sounds after the first half-hour, two after the first hour, and so on until eight bells marks the watch's end.

Watch Bells brings that traditional rhythm to your Mac, Windows, or Linux computer.

Download Watch Bells View source code
Time signal WB · 08
A brass ship's bell
Struck in pairs Eight bells · watch relieved

Signal book · 01

How ship's bells tell time

The count records elapsed half-hours within a watch - not the hour shown on a civil clock. Strikes come in pairs so they can be counted easily, with a final single strike for odd numbers. After eight bells, the next half-hour returns to one.

½ hour One
1 hour Two
1½ hours Three
2 hours Four
2½ hours Five
3 hours Six
3½ hours Seven
4 hours Eight

Watch bill · 02

The seven watches

Five watches occupy four hours apiece. The evening period is divided into two shorter dog watches, producing an odd number of duties so the same people need not stand the same watch every day.

Traditional naval watches
Watch Begins Ends Duration
Middle watch 00:00 04:00 4 hours
Morning watch 04:00 08:00 4 hours
Forenoon watch 08:00 12:00 4 hours
Afternoon watch 12:00 16:00 4 hours
First dog watch 16:00 18:00 2 hours
Last dog watch 18:00 20:00 2 hours
First watch 20:00 00:00 4 hours

Special order · 1797

Except, of course, when they don't.

The two dog watches interrupt the ordinary four-hour progression. In the Last Dog Watch, Watch Bells also follows the British convention associated with the Nore mutiny of 1797: five bells at 18:30 are omitted, the reputed signal for the mutiny to commence.

The result is the peculiar sequence below. At 18:30 the count returns to one; at 20:00, eight bells still marks the change to the First Watch.

First dog watch
Last dog watch
Relief
8
1
2
3
4
1
2
3
8

Engine room · 03

Old convention. Modern machinery.

Watch Bells is a small native Rust application. It waits in your menu bar or system tray, sounds the correct sequence at each half-hour boundary, and otherwise stays out of the way.

Construction Native Rust application

No Electron bloat or separate runtime.

Stations macOS · Windows · Linux

Works across all platforms.

Operation Offline and unobtrusive

Mute controls and no network dependency.

Inspection Open source

MIT licensed.

Ready for service

Put your computer on ship's time.

Current builds are available for macOS, Windows, and Linux.

Choose your download