From owner-svn-src-head@freebsd.org Fri Jun 23 02:19:07 2017 Return-Path: Delivered-To: svn-src-head@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 6D0FCD9A291; Fri, 23 Jun 2017 02:19:07 +0000 (UTC) (envelope-from cy.schubert@komquats.com) Received: from smtp-out-no.shaw.ca (smtp-out-no.shaw.ca [64.59.134.13]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "Client", Issuer "CA" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 06A0073C81; Fri, 23 Jun 2017 02:19:06 +0000 (UTC) (envelope-from cy.schubert@komquats.com) Received: from spqr.komquats.com ([96.50.22.10]) by shaw.ca with SMTP id OEBWd902VM9gtOEBXdrf5x; Thu, 22 Jun 2017 20:19:00 -0600 X-Authority-Analysis: v=2.2 cv=a+JAzQaF c=1 sm=1 tr=0 a=jvE2nwUzI0ECrNeyr98KWA==:117 a=jvE2nwUzI0ECrNeyr98KWA==:17 a=8nJEP1OIZ-IA:10 a=LWSFodeU3zMA:10 a=VxmjJ2MpAAAA:8 a=6I5d2MoRAAAA:8 a=qyDxTJV7AAAA:8 a=PYnjg3YJAAAA:8 a=YxBL1-UpAAAA:8 a=jiE4ZjxP2-fhC_OB0kgA:9 a=wPNLvfGTeEIA:10 a=7gXAzLPJhVmCkEl4_tsf:22 a=IjZwj45LgO3ly-622nXo:22 a=aVrITwz5twCY0aGzra0O:22 a=96-UuAdfYG6OSYlHWuPe:22 a=Ia-lj3WSrqcvXOmTRaiG:22 Received: from slippy.cwsent.com (slippy [10.1.1.91]) by spqr.komquats.com (Postfix) with ESMTPS id 04B6E72D; Thu, 22 Jun 2017 19:18:58 -0700 (PDT) Received: from slippy (localhost [127.0.0.1]) by slippy.cwsent.com (8.15.2/8.15.2) with ESMTP id v5N2Hgr7022456; Thu, 22 Jun 2017 19:17:42 -0700 (PDT) (envelope-from Cy.Schubert@cschubert.com) Message-Id: <201706230217.v5N2Hgr7022456@slippy.cwsent.com> X-Mailer: exmh version 2.8.0 04/21/2012 with nmh-1.6 Reply-to: Cy Schubert From: Cy Schubert X-os: FreeBSD X-Sender: cy@cwsent.com X-URL: http://www.cschubert.com/ To: Allan Jude cc: Cy Schubert , Ian Lepore , Cy Schubert , src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r320242 - head/etc/ntp In-Reply-To: Message from Cy Schubert of "Thu, 22 Jun 2017 19:10:55 -0700." <201706230210.v5N2At0l075844@slippy.cwsent.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Date: Thu, 22 Jun 2017 19:17:42 -0700 X-CMAE-Envelope: MS4wfKAe1EocQj9QTjVnyeUQZBfiCsaexNP2Z//m5+tOt1n4hOjH0+jzaylm0BDD6DuJC6sRFgk0LM/eTRnmS87Sz27VfVJvJsr4W4wV2y8gjXymhY3XQieq JhAWfBPgNFJMx55u/gxx82CxcDYdpbz4IWzleT4w6kYvJ/kTIOtxQnvJizhwN2AkWJaiUWWNWswxxAz4K0owcWsQIHPLJ0NLPHANtW66Cy8bg6sXpjYA4tnk VZow/oGJeOtHiAQtjIfs4kvFc2/lrXxSpQj2zSr9hvkgIMv2kuCCzEtd+i+0E18TDeg/mX5p42xQIHRrQMXMQPU6SoJWy7CVfIbrxf2LxuQ= X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 23 Jun 2017 02:19:07 -0000 In message <201706230210.v5N2At0l075844@slippy.cwsent.com>, Cy Schubert writes: > In message <2caa5927-9919-ce19-93f4-1005a5257295@freebsd.org>, Allan Jude > write > s: > > On 2017-06-22 21:04, Cy Schubert wrote: > > > In message <1498161747.66489.10.camel@freebsd.org>, Ian Lepore writes: > > >> On Thu, 2017-06-22 at 19:25 +0000, Cy Schubert wrote: > > >>> Author: cy > > >>> Date: Thu Jun 22 19:25:17 2017 > > >>> New Revision: 320242 > > >>> URL: https://svnweb.freebsd.org/changeset/base/320242 > > >>> > > >>> Log: > > >>>  Update leap-seconds to leap-seconds.3701462400. > > >>>  > > >>> > > >>> Modified: head/etc/ntp/leap-seconds > > >>> ===================================================================== > > >>> ========= > > >>> --- head/etc/ntp/leap-seconds Thu Jun 22 18:40:34 2017 > > >>> (r320241) > > >>> +++ head/etc/ntp/leap-seconds Thu Jun 22 19:25:17 2017 > > >>> (r320242) > > >>> @@ -128,7 +128,7 @@ > > >>>  # Washington, DC > > >>>  # jeffrey.prillaman@usno.navy.mil > > >>>  # > > >>> -# Last Update of leap second values:   6 Jul 2016 > > >>> +# Last Update of leap second values:  18 Apr 2017 > > >>>  # > > >>  # The following line shows this last update date in NTP > > >>> timestamp > > >>>  # format. This is the date on which the most recent change to > > >>> @@ -136,7 +136,7 @@ > > >>>  # be identified by the unique pair of characters in the first > > >>> two > > >>>  # columns as shown below. > > >>>  # > > >>> -#$  3676752000 > > >>> +#$  3701462400 > > >>>  # > > >> > > >> Where did this leapfile come from?  The last update of leap second > > >> values is supposed to change only when the actual list of offsets > > >> changes, not when the file is updated to just change an expiration > > >> date.  This is actually very explicitly documented in the file itself, > > >> just a few lines down from this change: > > > > > > The source of the leapfile is in the commit message. Here it is again: > > > > > > Obtained from: ftp://tycho.usno.navy.mil/pub/ntp/leap-seconds.3701462400 > > > > > >> > > >>  If an announcement by the IERS specifies that no leap second is > > >>  scheduled, then only the expiration date of the file will > > >>  be advanced to show that the information in the file is still > > >>  current -- the update time stamp, the data and the name of the file > > >>  will not change. > > >> > > >> > > >>> -# File expires on:  1 Jun 2017 > > >>> +# Updated through IERS Bulletin C 53 > > >>> +# File expires on:  1 Dec 2017 > > >>>  # > > >>> -#@ 3705264000 > > >>> +#@ 3721075200 > > >>>  # > > >> > > >> This expiration is wrong too, dangerously so IMO.  The data in the file > > >> is good through 12-31-2017-23:59:59, although historical practice has > > >> been to make the file expire a couple days before that.  Making it > > >> expire 31 days early is about the worst possible choice... some systems > > >> for notifying clients/consumers of an impending leap second (or the > > >> lack thereof) only do so during the last month before the leap > > >> opportunity -- this has the file expire just at the point such software > > >> would consider it authoratative for dissemination. > > > > > > My guess is that USNO may have had reason to do so. I'll keep an eye on > > > their next release of the file. > > >  > > >> > > >> I will note however, unlike the update date, there is no formal written > > >> description of how expiration date is determined, so the previous > > >> paragraph is just my opinion and experience working in the timing > > >> field. > > >> > > >> A leapfile without these problems can be found at > > >> > > >>   ftp://time.nist.gov/pub/leap-seconds.list > > > > > > We can use that instead. Attached is the diff between the USNO and NIST > > > versions of the file. > > > > > > One would think that two groups within the US Government might be able to > > > > produce a consistent leapfile. I suspect the real reason is that the USNO > > > > might have a different bureaucratic process than the NIST does. > > > > > >> > > >> > > >> -- Ian > > >> > > >>>  2272060800 10 # 1 Jan 1972 > > >>>  2287785600 11 # 1 Jul 1972 > > >>> @@ -216,5 +216,5 @@ > > >>>  # the hash line is also ignored in the > > >>>  # computation. > > >>>  # > > >>> -#h 63f8fea8 587c099d abcf130a ad525eae 3e105052 > > >>> +#h 3f004255 91f969f7 252361e5 27aa6754 eb6b7c72 > > >>>  # > > >>> > > >> > > > > > > I'll update to the NIST version of the file. > > > > > > > > > > > > > > > > > > > > > Cheers, > > > Cy Schubert > > > FreeBSD UNIX: Web: http://www.FreeBSD.org > > > > > > The need of the many outweighs the greed of the few. > > > > > > > The NIST version does seem to have a number of improvements, like > > corrected typos etc, but: > > > > -# Last Update of leap second values: 18 Apr 2017 > > +# Last Update of leap second values: 8 July 2016 > > > > The USNO one seems newer. A bit strange. > > That was Ian's issue. I think the following explanation makes sense: The > leap second itself wasn't updated in the NIST version file cine July 8, since The brain is faster than -- Cheers, Cy Schubert FreeBSD UNIX: Web: http://www.FreeBSD.org The need of the many outweighs the greed of the few. the fingers. > 2016, even though the file itself had been updated since then. I think > USNO sees that date as the date the file itself was updated, not the leap > second value, like NIST would appear it does. It sees like a fair > hypothesis. > > > -- > Cheers, > Cy Schubert > FreeBSD UNIX: Web: http://www.FreeBSD.org > > The need of the many outweighs the greed of the few. >