Leap Seconds in Unix Time

Discussions focus on whether Unix time includes leap seconds, the problems they cause in computing like glitches and non-monotonicity, alternatives like TAI over UTC, and calls to abolish leap seconds.

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Keywords

DST NTP time.Time UTC UT1 TZ POSIX nature.com i.e GPS leap seconds utc second rotation unix earth 00 time zones gps

Sample Comments

koolba Mar 8, 2018 View on HN

Only if they get rid of leap seconds as well.

wmf Aug 30, 2012 View on HN

Isn't Unix time UTC, which includes leap seconds which is what is causing all these glitches?

airstrike Aug 6, 2024 View on HN

yeah, but what about leap seconds?

account42 Mar 28, 2024 View on HN

Including leap seconds in unix time was a mistake - it should follow TAI instead of UTC and leave leap seconds entirely as a matter of the formatting/timezone code.

geofft Mar 11, 2021 View on HN

Are you counting leap seconds? (UNIX does not!)

beagle3 Jun 21, 2019 View on HN

What strategy are you guys using for leap seconds?

JimDabell Dec 12, 2022 View on HN

The leap second is being abandoned:https://www.nature.com/articles/d41586-022-03783-5

themerone Jan 14, 2022 View on HN

Leap seconds aren't a precision issue unless you need to calculate time delta's between events.

dkubb Feb 12, 2015 View on HN

You could side-step leap second issues by using a TAI based timestamp.

dwheeler Jan 9, 2021 View on HN

> Why has it never been appropriate?Because UTC has never worked that way.UTC is an international standard for a "time of day" standard where every second is exactly one second long and is boundedly synchronized to the rotation of the Earth. But the Earth wobbles. The UTC solution is to occasionally add or remove leap seconds, so sometimes you see 58, 59, 60, 0, and we might someday see 58,0.People complain that "leap seconds are hard" but there'