[154440] in North American Network Operators' Group
Re: F-ckin Leap Seconds, how do they work?
daemon@ATHENA.MIT.EDU (Jay Ashworth)
Tue Jul 3 22:47:49 2012
In-Reply-To: <952F93D4-E6B1-49C5-9694-E9292E3A4E36@delong.com>
From: Jay Ashworth <jra@baylink.com>
Date: Tue, 03 Jul 2012 22:47:02 -0400
To: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
No, it really shouldn't.
--
Sent from my Android phone with K-9 Mail. Please excuse my brevity.
Owen DeLong <owen@delong.com> wrote:
On Jul 3, 2012, at 1:09 PM, Saku Ytti wrote:
> On (2012-07-03 12:46 -0700), Owen DeLong wrote:
>
>> If you don't know that time is not monotonically increasing, then that only becomes a software bug when you codify your own ignorance into software you write.
>
> If only all software could be ordered from you Owen, but in practice this
> is not possible. Some code will be written less intelligent people. And
> reviewing any code doing foo = timestamp+offset and if now > foo, virtually
> never expects time to move backwards.
Sure, but even with that, 99% of it has only a passing 'interesting' effect and
then recovers.
> UTC doesn't move backwards (it goes 59 -> 60 -> 00). TAI does not move
> backwards. Unixtime moves backwards, like spanish inquisition no one
> expects that.
UTC (and the system clock) should not move backwards, but, rather they repeat
second 59. UTC goes 58->59->00 most of the time, but during a leap second, it
should go 58->59->59->00). It's not so much going backwards as dropping a chime.
>> It is well known that leap seconds exist.
>
> Quite. But it is not well known that unixtime travels backwards.
>
In part because it shouldn't actually do so. It should simply chime 59 twice.
Owen
