Unit of time

A unit of time or midst unit is any particular time interval, used as a standard way of measuring or expressing duration. The base unit of time in the International System of Units (SI) and by extension most of the Western world, is the second, defined as about 9 billion oscillations of the caesium atom.

Note: The light-year is not a unit of time, but a unit of length of about 9.5 petametres (9 454 254 955 488 kilometers).

List
+   Unit Length, Duration and Size Notes Planck time    The amount of time light takes to travel one Planck length. yoctosecond  One septillionth of a second. jiffy (physics)   The amount of time light takes to travel one fermi (about the size of a nucleon) in a vacuum. zeptosecond  One sextillionth of a second. Time measurement scale of the NIST strontium atomic clock. Smallest fragment of time currently measurable is 247 zeptoseconds. attosecond    One quintillionth of a second. femtosecond    One quadrillionth of a second. Pulse time on fastest lasers. svedberg  Time unit used for sedimentation rates (usually of proteins). picosecond    One trillionth of a second. nanosecond    One billionth of a second. Time for molecules to fluoresce. shake  10 nanoseconds, also a casual term for a short period of time. microsecond   One millionth of a second. Symbol is µs centimillisecond   One hundred thousandth of a second or one hundredth of a millisecond. decimillisecond   One ten-thousandth of a second or one tenth of a millisecond. millisecond    One thousandth of a second. Shortest time unit used on stopwatches. centisecond    One hundredth of a second. jiffy (electronics)   or   Used to measure the time between alternating power cycles. Also a casual term for a short period of time. decisecond    One tenth of a second. quadrisecond / semisemisecond    One quarter of a second. semisecond / half second    One half of a second. second    SI Base unit. decasecond   half a minute    It’s known by math. minute    milliday    Also marketed as a ".beat" by the Swatch corporation; Milliday is a more accurate name. moment  ( on average)  Medieval unit of time used by astronomers to compute astronomical movements, length varies with the season. hectosecond    1 minute and 40 seconds ke    14 minutes and 24 seconds kilosecond    16 minutes and 40 secondshalf an hour   It’s known by math. hour    decakilosecond    Ten thousand seconds or ten kiloseconds.Half an day  Its known by math. day    Longest unit used on stopwatches and countdowns. hectokilosecond    One hundred thousand seconds or one hundred kiloseconds. week    Also called "sennight". megasecond    277.777778333333 hours or about 1 week and 4.6 days. fortnight    14 days lunar month   Various definitions of lunar month exist. month  28-31 days  Occasionally calculated as 30 days. quarter and season    quadrimester    semester   A division of the academic year. Literally "six months", also used in this sense. half year    lunar year    year     common year    52 weeks and 1 day. tropical year  , Extract of page 18 Average. Gregorian year   Average. sidereal year  leap year     and  biennium     triennium    quadrennium     olympiad    lustrum    decade     indiction    gigasecond    16,666,666.6667 minutes or about 31.7 years. jubilee  century     millennium    Also called "kiloannum". terasecond    About 31,709 years. megaannum  Also called "Megayear." 1,000 millennia (plural of millennium), or 1 million years. petasecond    About 31,709,791 years. galactic year The amount of time it takes the Solar System to orbit the center of the Milky Way Galaxy one time. Around 230,000,000 years. cosmological decade varies 10 times the length of the previouscosmological decade, with CÐ 1 beginningeither 10 seconds or 10 years after theBig Bang, depending on the definition. gigaannum   Also refers to an indefinite period of time, otherwise is 1,000,000,000 years. exasecond    About 31,709,791,983 years. zettasecond    About 31,709,791,983,764 years. yottasecond    About 31,709,791,983,764,584 years.Age of universe13700000000yearsRoughly 4.35 yottaseconds

References

Category:Units of time