Re: Predictable Internet Time

"Patrik Fältström " <paf@frobbit.se> Tue, 28 March 2017 06:38 UTC

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From: "Patrik =?utf-8?b?RsOkbHRzdHLDtm0=?=" <paf@frobbit.se>
To: "Joe Touch" <touch@isi.edu>
Cc: "Phillip Hallam-Baker" <phill@hallambaker.com>, "Tony Finch" <dot@dotat.at>, "IETF Discussion Mailing List" <ietf@ietf.org>, "Jared Mauch" <jared@puck.nether.net>
Subject: Re: Predictable Internet Time
Date: Tue, 28 Mar 2017 08:37:56 +0200
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Joe,

I have read your I-D and like it! Let me start there :-)

What I think is not clear enough is the problem with POSIX, and it should be more clear in some place, maybe section 6.1, that POSIX definition which is in use in quite a number of systems do not handle leap second very well. Too many do believe the time_t definitions include the number of seconds since epoch when in reality it does not (as you note in the definitions).

One could even question whether it is Continuous as two seconds will have the same number since epoch around the addition of a leap second (the last second of the day with leap second and the first the day after the addition of leap second). I claim it is not as if you look at also fractions of seconds it will go backward like:

:
(N-1).0
(N-1).1
:
(N-1).9
N.0
N.1
:
N.9
N.0
N.1
:
N.9
(N+1).0
(N+1).1
:

There are some people that have suggested a change, for example <http://www.cl.cam.ac.uk/~mgk25/time/c/> but I have not seen any movement. Maybe you know more than me on this?

   Patrik

On 27 Mar 2017, at 21:34, Joe Touch wrote:

> Hi, all,
>
> I've submitted the time frame discussion intended to resolve this issue, which also recently arouse on another mailing list. Further discussion on this draft will occur on the ART mailing list (art@ietf.org).
>
> Joe
>
> -----------
>
> A new version of I-D, draft-touch-time-01.txt
> has been successfully submitted by Joe Touch and posted to the IETF repository.
>
> Name:		draft-touch-time
> Revision:	01
> Title:		Resolving Multiple Time Scales in the Internet
> Document date:	2017-03-27
> Group:		Individual Submission
> Pages:		17
> URL:            https://www.ietf.org/internet-drafts/draft-touch-time-01.txt Status:         https://datatracker.ietf.org/doc/draft-touch-time/
> Htmlized:       https://tools.ietf.org/html/draft-touch-time-01 Htmlized:       https://datatracker.ietf.org/doc/html/draft-touch-time-01 Diff:           https://www.ietf.org/rfcdiff?url2=draft-touch-time-01
>
> Abstract:
>    Internet systems use a variety of time scales, which can complicate   time comparisons and calculations. This document explains these   various ways of indicating time and explains how they can be used   together safely. This document is intended as a companion to   Internet time as discussed in RFC 3339.