Seonglae ChoTAI and POSIX time ignore leap seconds and always assume a day is 86,400 seconds. UTC can have 86,399 seconds due to leap seconds, and since TAI does not adjust its time when leap seconds occur, the difference between TAI time and UTC time accumulates over time. UTC considers leap seconds because it's based on astronomical standards. While both POSIX and TAI ignore leap seconds, TAI is a linear time that accurately measures real seconds, while POSIX is a UTC-based time that ignores leap seconds. Since 1972, starting with 10 seconds, 27 additional seconds have accumulated, making UTC has been exactly 37 seconds behind TAI.
Smearing is a method of gradually adjusting time to prevent large jumps when leap seconds occur. This approach is used to reduce discrepancies caused by leap seconds without directly reflecting them in POSIX time. However, the time adjustment method is not standardized and can be implemented differently by different systems (typically by distributing one second over a day). Due to this complexity and a major system failure in 2012, there are movements to eliminate leap seconds altogether until 2035.
Time Standards
Time Notion
Time standards are very complexrp
Falsehoods programmers believe about time, in a single list
Falsehoods programmers believe about time, in a single list · GitHub
https://gist.github.com/timvisee/fcda9bbdff88d45cc9061606b4b923ca
The flow
Where does my computer get the time from? – Tony Finch
This week I was in Rotterdam for a RIPE meeting.
On Friday morning I gave a lightning talk called where does my
computer get the time from?
The RIPE meeting website has a copy of my slides and a video of the
talk; this is a blogified low-res version of the slides with a rough
and inexact transcript.
https://dotat.at/@/2023-05-26-whence-time.html
These 'chip-scale' atomic clocks extend precise timing beyond GPS limits
Scientists have developed new miniaturized chip-scale atomic clocks that can bring accuracy and stability in regions where GPS doesn't work.
https://interestingengineering.com/innovation/chip-scale-atomic-clocks-accuracy-gps
GPS, UTC, and TAI Clocks
GPS, Global Positioning System time, is the atomic time scale implemented by the atomic clocks in the GPS ground control stations and the GPS satellites themselves. GPS time was zero at 0h 6-Jan-1980 and since it is not perturbed by leap seconds GPS is now ahead of UTC by
http://leapsecond.com/java/gpsclock.htm
타임존과 moment isBetween('어제', '오늘')
한국 사람은 익숙하지 않은 썸머타임. 썸머타임이 있는 나라는 하루가 25시간이나 23시간일 때도 있다. 하루는 24시간인데 왜 들쑥날쑥하는 걸까? 전 세계의 다양한 시간대를 표시하는 방법으로 타임존이 있다. 브라우저는 타임존을 지원하기 위해 몇 가지 방법을 제공한다. 그러나 이 방법만으로는 우리의 웹 서비스가 전 세계 사용자들의 다양한 타임존을 만족시키는 어렵다.
https://ui.toast.com/weekly-pick/ko_20200928/
