Unlike civil clock bells, the strikes of the bell do not accord to the number of the hour. Instead, there are eight bells, one for each half-hour of a four-hour watch.
The classical system was:
| Number of bells | Middle watch | Morning watch | Forenoon watch | Afternoon watch | First dog watch | Last dog watch | First watch |
| One bell | 0:30 | 4:30 | 8:30 | 12:30 | 16:30 | 18:30 | 20:30 |
| Two bells | 1:00 | 5:00 | 9:00 | 13:00 | 17:00 | 19:00 | 21:00 |
| Three bells | 1:30 | 5:30 | 9:30 | 13:30 | 17:30 | 19:30 | 21:30 |
| Four bells | 2:00 | 6:00 | 10:00 | 14:00 | 18:00 | 22:00 | |
| Five bells | 2:30 | 6:30 | 10:30 | 14:30 | 22:30 | ||
| Six bells | 3:00 | 7:00 | 11:00 | 15:00 | 23:00 | ||
| Seven bells | 3:30 | 7:30 | 11:30 | 15:30 | 23:30 | ||
| Eight bells | 4:00 | 8:00 | 12:00 | 16:00 | 20:00 | 0:00 |
The hours between 16:00 and 20:00 are so arranged because that watch (the "dog watch", which is cur-tailed) was divided into two. The odd number of watches aimed to give each man a different watch each day.
Some domestic "ship's bell" clocks use a simpler system:
| Number of bells | Hour (a.m. and p.m.) | ||
| One bell | 12:30 | 4:30 | 8:30 |
| Two bells | 1:00 | 5:00 | 9:00 |
| Three bells | 1:30 | 5:30 | 9:30 |
| Four bells | 2:00 | 6:00 | 10:00 |
| Five bells | 2:30 | 6:30 | 10:30 |
| Six bells | 3:00 | 7:00 | 11:00 |
| Seven bells | 3:30 | 7:30 | 11:30 |
| Eight bells | 4:00 | 8:00 | 12:00 |
The number of bells may be used to refer to the hour so indicated.