Seconds to Weeks (s to wk)

1 second equals 0.000001653439153 weeks (rounded).

1 second = 0.000001653439153 weeks

How to convert seconds to weeks

To convert seconds to weeks, multiply the number of seconds by 0.000001653439153. The factor is rounded to 10 significant digits. To go the other way, multiply weeks by 604,800.

weeks = seconds × 0.000001653439153

Example: 10 seconds = 0.00001653439153 weeks.

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

Second (s)

Metric (SI)Current unit

The SI base unit of time, defined by the radiation frequency of the cesium-133 atom: 9,192,631,770 cycles per second.

Our word second is a leftover of Latin. Medieval scholars divided a degree, and later the hour, into 60 parts called pars minuta prima, the first small part, and divided those again into pars minuta secunda, the second small part. NIST traces the roots further back: Babylonian and Greek astronomers split the circle into 360 degrees, and around 150 C.E. Ptolemy split each degree into 60 minutes and each minute into 60 seconds. Clocks that could show seconds appeared only in the later 16th century, and Christiaan Huygens's pendulum clock of 1656 was the first able to keep time accurately to the second.

For most of history the second was a fraction of a day, and in 1956 it was redefined as a fraction of the tropical year, a definition the SI took over in 1960. In 1967 the 13th CGPM switched to atoms: 9,192,631,770 periods of the radiation tied to a hyperfine transition of caesium-133. The 2019 SI revision restated this by fixing the caesium frequency at 9,192,631,770 hertz. NIST reports that commercial caesium clocks stay within about a three-millionth of a second per year, and experimental clocks based on other atoms are roughly ten thousand times more precise.

The second is the reference unit for time on this site.

Sources: NIST: the second and the SI redefinition; BIPM: SI Brochure, 9th edition; Wikipedia: Second

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

Related conversions

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