Decades to Millennia (dec to ky)
1 decade equals 0.01 millennia exactly.
How to convert decades to millennia
To convert decades to millennia, multiply the number of decades by 0.01. This factor is exact. To go the other way, multiply millennia by 100.
millennia = decades × 0.01
Example: 10 decades = 0.1 millennia.
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
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
Millennium (ky)
One thousand years.
Latin supplied the parts of millennium: mille, a thousand, and annus, a year. The plural can be millennia or millenniums. Because a thousand years exceeds any one person's reach, the word acquired religious overtones in the idea of millenarianism, though the unit itself is a plain count of years. When the year 2000 arrived, a new question came with it: was this the start of the third millennium, or was that a year away?
A millennium is 1,000 years, here 1,000 average Gregorian years. The 2001 camp points out that there is no year zero, so the first millennium ran from year 1 to year 1000. The 2000 camp followed the odometer effect, in which the hundreds and thousands digits roll over together. Most people celebrated in 2000, and the celebrations in 2001 were mostly routine, although the U.S. Naval Observatory, Cuba and Japan did mark the strict date. The evolutionary biologist Stephen Jay Gould observed that the strict view dominated at the start of the 20th century and the popular view at its end.
1 millennium = 31,556,952,000 seconds (exactly).
Sources: Wikipedia: Millennium; Wikipedia: Millenarianism
Related conversions
- Millennia to decades (reverse)
- Decades to seconds
- Decades to minutes
- Decades to hours
- Decades to days
- Decades to weeks
- Decades to months
- Decades to years
- Decades to milliseconds
- Decades to microseconds
- Decades to nanoseconds
- Decades to centuries
- Seconds to millennia
- Minutes to millennia
- Hours to millennia
- Days to millennia
- Weeks to millennia
- Months to millennia
- Years to millennia
- Milliseconds to millennia
- Microseconds to millennia
- Nanoseconds to millennia
- Centuries to millennia
See all time units.