# Instant > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Instant > Markdown URL: https://mediated.wiki/source/Instant.md > Source: https://en.wikipedia.org/wiki/Instant > Source revision: 1343213547 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) Shortest interval in time In [physics](/source/Physics) and the [philosophy of science](/source/Philosophy_of_science), **instant** refers to an [infinitesimal](/source/Infinitesimal) interval in [time](/source/Time), whose passage is instantaneous. In ordinary speech, an **instant** has been defined as "a point or very short space of time," a notion deriving from its etymological source, the Latin verb *instare*, from *in-* + *stare* ('to stand'), meaning 'to stand upon or near.'[1] The continuous nature of time and its infinite divisibility was addressed by [Aristotle](/source/Aristotle) in his *[Physics](/source/Physics_(Aristotle))*, where he wrote on [Zeno's paradoxes](/source/Zeno's_paradoxes). The philosopher and mathematician Bertrand Russell was still seeking to define the exact nature of an instant thousands of years later.[2] As of October 2020[\[update\]](https://en.wikipedia.org/w/index.php?title=Instant&action=edit), the smallest time interval certified in regulated measurements is on the order of 397 zeptoseconds (397 × 10−21 seconds).[3] ## In correspondence In correspondence, particularly before the twentieth century, instant (usually abbreviated to inst.) can be used to indicate "of the current month". For example, "the 11th inst." means the 11th day of the current month.[4][5] Its use is consistent with the Latin *proximo* (prox.) for the following month, and *ultimo* (ult.) for the month just past.[6] ## See also Look up ***[instant](https://en.wiktionary.org/wiki/Special:Search/instant)*** in Wiktionary, the free dictionary. - [Infinitesimal](/source/Infinitesimal) - [Planck time](/source/Planck_time) - [Present](/source/Present) ## References 1. **[^](#cite_ref-1)** *Webster's New World College Dictionary*, 4th ed. (1999), p. 740. 1. **[^](#cite_ref-2)** W. Newton-Smith (1984), ["The Russellian construction of instants"](https://books.google.com/books?id=29E9AAAAIAAJ&pg=PA129), *The structure of time*, Routledge, p. 129, [ISBN](/source/ISBN_(identifier)) [978-0-7102-0389-2](https://en.wikipedia.org/wiki/Special:BookSources/978-0-7102-0389-2) 1. **[^](#cite_ref-3)** ["Zeptoseconds: New state record in short time measurement"](https://www.sciencedaily.com/releases/2020/10/201016090209.htm). Science Daily. 2020-10-16. Retrieved 2010-05-12. 1. **[^](#cite_ref-4)** ["instant"](https://www.oxfordreference.com/display/10.1093/oi/authority.20110803100005710). *oxfordreference.com*. [Oxford University Press](/source/Oxford_University_Press). Retrieved 2024-07-05. 1. **[^](#cite_ref-5)** Chambers, Alfred B. (1900). [*The New Century Standard Letter-Writer*](https://www.gutenberg.org/cache/epub/56911/). Chicago: [Laird & Lee](/source/Laird_%26_Lee). p. 258. 1. **[^](#cite_ref-6)** Crowther, Mary Owens (1922). [*How to Write Letters*](https://www.gutenberg.org/cache/epub/22222/pg22222-images.html). New York: [Garden City Publishing Co.](/source/Doubleday_(publisher)) p. 41. v t e Time Key concepts Past Present Future Eternity Measurement and standards Chronometry UTC Universal Time TAI Unit of time Orders of magnitude (time) Measurement systems Italian six-hour clock Thai six-hour clock 12-hour clock 24-hour clock Relative hour Daylight saving time Chinese Decimal Hexadecimal Hindu Jain Metric Roman Sidereal Solar Time zone Calendars Main types Solar Lunar Lunisolar Gregorian Julian Hebrew Islamic Solar Hijri Chinese Hindu Panchang Maya List Clocks Main types astronomical astrarium atomic quantum hourglass marine sundial watch 24-hour wristwatch mechanical stopwatch water-based Cuckoo clock Digital clock Grandfather clock History Timeline Chronology History Astronomical chronology Big History Calendar era Deep time Periodization Regnal year Timeline Philosophy of time A series and B series B-theory of time Chronocentrism Duration Endurantism Eternal return Eternalism Event Moving spotlight theory Perdurantism Presentism Temporal finitism Temporal parts "The Unreality of Time" Religion Mythology Ages of Man Destiny Immortality Dreamtime Kāla Time and fate deities Father Time Wheel of time Kalachakra Human experience and use of time Chronemics Generation time Mental chronometry Music tempo time signature Rosy retrospection Tense–aspect–mood Time management Yesterday – Today – Tomorrow Time in science Geology Geological time age chron eon epoch era period Geochronology Geological history of Earth Physics Absolute space and time Arrow of time Chronon Coordinate time Instant Proper time Spacetime Theory of relativity Time domain Time translation symmetry Time reversal symmetry Other fields Chronological dating Chronobiology Circadian rhythms Clock reaction Glottochronology Time geography Related Leap year Memory Moment Sabbath Space System time Tempus fugit Time capsule Time immemorial Time travel Time value of money Category Commons v t e Time measurement and standards International standards Coordinated Universal Time offset UT ΔT DUT1 International Earth Rotation and Reference Systems Service ISO 31-1 ISO 8601 International Atomic Time 12-hour clock 24-hour clock Barycentric Coordinate Time Barycentric Dynamical Time Civil time Daylight saving time Geocentric Coordinate Time International Date Line IERS Reference Meridian Leap second Solar time Terrestrial Time Time zone 180th meridian Obsolete standards Ephemeris time Greenwich Mean Time Prime meridian Time in physics Absolute space and time Spacetime Chronon Coordinate time Discrete time and continuous time Proper time Theory of relativity Time dilation Gravitational time dilation Time domain Time-translation symmetry T-symmetry Chronometry Clock Astrarium Atomic clock Complication History of timekeeping devices Hourglass Marine chronometer Marine sandglass Radio clock Watch stopwatch Water clock Sundial Dialing scales Equation of time History of sundials Sundial markup schema Calendar Gregorian Hebrew Hindu Holocene Islamic (lunar Hijri) Julian Solar Hijri Astronomical Dominical letter Epact Equinox Intercalation Julian day Leap year Lunar Lunisolar Solar Solstice Tropical year Weekday determination Weekday names Archaeology and geology Chronological dating Geologic time scale International Commission on Stratigraphy Astronomical chronology Galactic year Nuclear timescale Precession Sidereal time Other units of time Instant Flick Shake Jiffy Second Minute Moment Hour Day Week Fortnight Month Year Olympiad Lustrum Decade Century Saeculum Millennium Related topics Orders of magnitude Chronology Duration music Mental chronometry Decimal time Metric time System time Time value of money Timekeeper This philosophy of science-related article is a stub. You can help Wikipedia by adding missing information. - [v](https://en.wikipedia.org/wiki/Template:Science-philo-stub) - [t](/source/Template_talk%3AScience-philo-stub) - [e](https://en.wikipedia.org/wiki/Special:EditPage/Template:Science-philo-stub) This time-related article is a stub. You can help Wikipedia by adding missing information. - [v](https://en.wikipedia.org/wiki/Template:Time-stub) - [t](/source/Template_talk%3ATime-stub) - [e](https://en.wikipedia.org/wiki/Special:EditPage/Template:Time-stub) --- Adapted from the Wikipedia article [Instant](https://en.wikipedia.org/wiki/Instant) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Instant?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.