[154437] in North American Network Operators' Group
Re: F-ckin Leap Seconds, how do they work?
daemon@ATHENA.MIT.EDU (Vadim Antonov)
Tue Jul 3 21:56:09 2012
Date: Tue, 03 Jul 2012 18:55:29 -0700
From: Vadim Antonov <avg@kotovnik.com>
To: nanog@nanog.org
In-Reply-To: <17BF05B7-AD43-49DA-A9A6-04BA5AE67D51@ucolick.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On 7/3/2012 6:28 PM, Steve Allen wrote:
> On 2012 Jul 3, at 18:13, Vadim Antonov wrote:
>> PS. I would vote for using TAI instead of UTC as the
>> non-relativistic time base in computer systems.
>
> A problem with the use of TAI is that the BIPM and CCTF (who make
> TAI) expressed strongly that they do not want it used as a system
> time in document CCTF09-27
> http://www.bipm.org/cc/CCTF/Allowed/18/CCTF_09-27_note_on_UTC-ITU-R.pdf
> so strongly that they end by contemplating the discontinuation
> of TAI.
There's always a possibility of using pseudo-TAI internally by
reconstructing it from UTC. This is not the best solution (because it
requires systems to have long-term memory of past leap seconds, or
ability to access a reliable storage of such), but at least this removes
the burden of doing complicated time handling from application software.
Actually, what they are saying is that they would discontinue TAI *if*
definition of UTC is amended to remove future leap seconds. The
document makes it clear that they recognize the necessity of continuous
coordinate time standard.
--vadim
