WATCHES

Charmed has a wonderful Weems and Plath Ship's Bell. Like all ship's
bells, it counts half hours for four hours, then it starts over. At
04:30, 08:30, 12:30, 16:30, 20:30, and 00:30, the bell rings one time.
At 05:00, 09:00, 13:00, 17:00, 21:00, 01:00, the bell rings two
times, and so on. At six times during the day, 04:00, 08:00, 12:00,
16:00, 20:00, 24:00, the bell rings eight times. These are the times
when the watch historically changed.

The different watches had names:

2000 2400 FIRST WATCH
2400 0400 MIDDLE WATCH
0400 0800 MORNING
0800 1200 FORENOON
1200 1600 AFTERNOON
1600 1800 FIRST DOG WATCH
1800 2000 SECOND DOG WATCH

The two Dog Watches compressed the period available for dinner or
supper. The Dog Watches also shifted the time that sailors would
stand watch so sailors wouldn't stand watch the same time every day,
day in and day out.