Seconds to Decades (s to dec)
1 second equals 3.168873851×10⁻⁹ decades (rounded).
How to convert seconds to decades
To convert seconds to decades, multiply the number of seconds by 3.168873851×10⁻⁹. The factor is rounded to 10 significant digits. To go the other way, multiply decades by 315,569,520.
decades = seconds × 3.168873851×10⁻⁹
Example: 10 seconds = 3.168873851×10⁻⁸ decades.
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)
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
Decade (dec)
Ten years.
Greek dekas, a group of ten, gave English decade, and the Latin equivalent decennium survives in words like decennial. The idea of naming whole decades is newer. The convention of grouping years by their tens digit, so that 1960 to 1969 is the 1960s, became common in the late 19th century, and the 20th century then produced a gallery of nicknames such as the Roaring Twenties and the Swinging Sixties.
A decade is ten years, which on this site means ten average Gregorian years. The two counting styles can disagree, in the same way as with centuries: since the AD calendar has no year zero, a strict reading makes the first decade run from year 1 to year 10. A 2019 YouGov poll of 13,582 US adults found 64 percent expected the next decade to be 2020 to 2029, 17 percent said 2021 to 2030, and 19 percent did not know. Most people prefer the zero-to-nine version.
1 decade = 315,569,520 seconds (exactly).
Sources: Wikipedia: Decade; Wikipedia: Year zero
Related conversions
- Decades to seconds (reverse)
- Seconds to minutes
- Seconds to hours
- Seconds to days
- Seconds to weeks
- Seconds to months
- Seconds to years
- Seconds to milliseconds
- Seconds to microseconds
- Seconds to nanoseconds
- Seconds to centuries
- Seconds to millennia
- Seconds to picoseconds
- Minutes to decades
- Hours to decades
- Days to decades
- Weeks to decades
- Months to decades
- Years to decades
- Milliseconds to decades
- Microseconds to decades
- Nanoseconds to decades
- Centuries to decades
- Millennia to decades
See all time units.