Weeks to Ship's Watches (wk to watch)

1 week equals 42 ship's watches exactly.

1 week = 42 ship's watches

How to convert weeks to ship's watches

To convert weeks to ship's watches, multiply the number of weeks by 42. This factor is exact. To go the other way, multiply ship's watches by 0.02380952381 (rounded).

ship's watches = weeks × 42

Example: 10 weeks = 420 ship's watches.

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

Week (wk)

CalendarCurrent unit

Seven days. The seven-day week comes from the ancient Near East and is nearly universal in the modern calendar.

Nothing in the sky produces a seven-day cycle, which makes the week a human invention with a contested pedigree. Babylonians marked the 7th, 14th, 21st and 28th of the lunar month as special, but that was not a continuous cycle. A continuous seven-day cycle tied to the Sabbath is attested in Judaism by the 6th century BC at the latest, and scholars disagree on whether it was borrowed from Babylon or developed independently. The Romans later used a week named for the Sun, the Moon and the five visible planets, and in AD 321 Emperor Constantine decreed it across the empire.

A week is seven days, or 604,800 seconds, and it divides evenly into neither months nor years, which is why calendars shift against it. The ISO 8601 standard starts each week on Monday and assigns week 1 to the week containing the year's first Thursday, so some years have a week 53. Other societies used different lengths: Rome had an eight-day market cycle, and revolutionary France used a ten-day week from 1793 to 1802. The English word comes from Old English wice, meaning a turn or succession.

1 week = 604,800 seconds (exactly).

Sources: Wikipedia: Week; Wikipedia: ISO week date

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

Related conversions

See all time units.