Re:2016 will be one second longer
by joeax on Friday December 23, 2016 @11:35AM
(#13245592)
Your phone should update at one second before midnight UTC. So if your in EST then at 6:59:59, watch for 59 to be counted twice.
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Re:2016 will be one second longer
by gshubert17 on Friday December 23, 2016 @12:14PM
(#13245844)
I believe 6:59:59 will be followed by 6:59:60. See the screen shot I took of a leap second added in 2008.
Yep. The extra second is the 60th second. http://earthsky.org/human-world/leap-second-june-30-december...
There's a bunch of ways the leap second can be reflected. :59 twice, :60, leap second smearing (adding small amounts of time leading up to midnight). How your particular system reacts depends on the use, how it's configured, etc.
That makes sense. I was being slightly facetious, and I think most devices would NTP re-sync after some interval. But it would be cool if my phone did in fact show 3:59:60 (I'm pacific time) and/or analog smartwatch paused on the 59 for two seconds.
Re:2016 will be one second longer
by andrewstuart2 on Friday December 23, 2016 @11:45AM
(#13245649)
Have our timekeeping protocols really accounted for future events like that? It's my understanding that NTP really only synchronizes time periodically.
Your phone/computer should (according to the standard) know when the leap second is and apply it. NTP etc. transmit the information about leap seconds well in advance.
It is possible your device may not see a leap second, only eventually observe that it is running one second slow, and smear to correct for that.
NTP includes flags for "leap second at the end of day", so devices that check NTP time at least once a day get the information. The systems internal list of leap seconds is possibly updated before that through normal system updates.