Ship's Watches to Months (watch to mo)

1 ship's watch equals 0.005475814014 months (rounded).

1 ship's watch = 0.005475814014 months

How to convert ship's watches to months

To convert ship's watches to months, multiply the number of ship's watches by 0.005475814014. The factor is rounded to 10 significant digits. To go the other way, multiply months by 182.62125.

months = ship's watches × 0.005475814014

Example: 10 ship's watches = 0.05475814014 months.

Months and years are not constant. This site uses the average Gregorian year of 365.2425 days, so one 'year' converts to 365.2425 days, not 365; use 'common year' for exactly 365 days.

About these units

Ship's Watch (watch)

NauticalTraditional unit (still used in some regions)

Four hours, the standard duty period at sea. The 'dog watches' of the evening are split into two hours each.

Naval and merchant crews divide the day into watches so that the ship is never left unattended. A normal watch lasts four hours, and its length is the basis for the figure used here, 14,400 seconds. The traditional scheme described by Wikipedia had five four-hour watches and two two-hour dog watches, named the first, middle, morning, forenoon and afternoon watches, with the afternoon watch ending at 1600.

Splitting the 1600 to 2000 period into a first and second dog watch gives an odd number of watches per day, so each crew member's schedule shifts from day to day, and it also lets everyone eat an evening meal. Time on board is marked with the ship's bell, struck every half hour so that eight bells ends a four-hour watch. Merchant ships typically keep six four-hour watches instead, which makes the pattern consistent.

1 ship's watch = 14,400 seconds (exactly).

Sources: Wikipedia: Watchkeeping; Wikipedia: Ship's bell

Month (mo)

CalendarCurrent unit

One twelfth of an average Gregorian year: 30.436875 days. Calendar months actually range from 28 to 31 days.

Month and Moon are cognates, and the unit began as the Moon's cycle of phases, about 29.53 days from one new moon to the next. The trouble is that 12 of these fall short of a solar year, so calendars have had to choose. The Islamic calendar stays purely lunar, so its year is about 11 days shorter than the solar year, while the Hebrew calendar is lunisolar, using a 19-year cycle with an extra month. Even the start of a lunar month is still debated between observing the crescent and calculating it.

Gregorian months are a compromise that drifted far from the Moon. Their lengths run from 28 to 31 days, and this site uses their mean of 30.436875 days, one twelfth of the average year. The names also keep Roman history: September to December preserve the Latin numerals for seven to ten, since they were originally the seventh to tenth months, and Quintilis and Sextilis were renamed for Julius Caesar and Augustus. When a contract says month, check whether it means a calendar month or thirty days.

1 month = 2,629,746 seconds (exactly).

Sources: Wikipedia: Month; Wikipedia: Lunar calendar

Related conversions

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