Editing Unix time (section)

{{short description|Date and time representation system widely used in computing}}
{{Redirect|January 1, 1970|the date|January 1, 1970 (date)}}
{{Redirect|Epoch time|other epochs|Epoch (computing)|the newspaper|The Epoch Times{{!}}''The Epoch Times''}}
{{Use dmy dates|date=May 2023}}

[[File:1000000000seconds.jpg|right|thumb|Unix time passed {{val|1000000000}} seconds on 2001-09-09T01:46:40Z.<ref name="wired-farhad">{{Cite magazine |last=Farhad |first=Manjoo |date=8 September 2001 |title=Unix Tick Tocks to a Billion |language=en-US |magazine=Wired |url=https://www.wired.com/2001/09/unix-tick-tocks-to-a-billion/ |access-date=16 October 2022 |issn=1059-1028 |archive-date=11 September 2022 |archive-url=https://web.archive.org/web/20220911005342/https://www.wired.com/2001/09/unix-tick-tocks-to-a-billion/ |url-status=live }}</ref> It was celebrated in Copenhagen, Denmark, at a party held by the [[Danish UNIX User Group]] at 03:46:40 local time.]]

'''Unix time'''{{efn|Unix time is also known as "Epoch time", "[[POSIX]] time",<ref>{{Cite web |url=https://pubs.opengroup.org/onlinepubs/9699919799/xrat/V4_xbd_chap04.html |title=The Open Group Base Specifications Issue 7, Rationale: Base Definitions, section A.4 General Concepts |publisher=[[The Open Group]] |access-date=9 September 2019 |archive-date=15 November 2017 |archive-url=https://web.archive.org/web/20171115154605/http://pubs.opengroup.org/onlinepubs/9699919799/xrat/V4_xbd_chap04.html |url-status=live }}</ref> "seconds since the Epoch",<ref name="single-unix-spec-4.16">{{cite web|url=http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html#tag_04_16|title=The Open Group Base Specifications Issue 7, section 4.16 Seconds Since the Epoch|publisher=[[The Open Group]]|access-date=22 January 2017|archive-date=22 December 2017|archive-url=https://web.archive.org/web/20171222113543/http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html#tag_04_16|url-status=live}}</ref> "Unix timestamp" or "UNIX Epoch time".<ref>{{Cite book|title=Beginning Linux Programming|last1=Matthew|first1=Neil|last2=Stones|first2=Richard|publisher=Wiley|year=2008|isbn=978-0-470-14762-7|location=Indianapolis, Indiana, US|pages=148|chapter=The Linux Environment}}</ref>}} is a date and time representation widely used in [[computing]]. It measures time by the number of non-[[leap second]]s that have elapsed since 00:00:00 [[Coordinated Universal Time|UTC]] on 1&nbsp;January 1970, the Unix [[Epoch (computing)|epoch]]. For example, at midnight on 1 January 2010, Unix time was 1262304000.

Unix time originated as the [[system time]] of [[Unix]] operating systems. It has come to be widely used in other computer [[operating systems]], [[file systems]], [[programming languages]], and [[databases]]. In modern computing, values are sometimes stored with higher [[Data granularity|granularity]], such as [[microsecond]]s or [[nanosecond]]s.