Re: Predictable Internet Time

Phillip Hallam-Baker <phill@hallambaker.com> Fri, 21 April 2017 18:35 UTC

Return-Path: <hallam@gmail.com>
X-Original-To: ietf@ietfa.amsl.com
Delivered-To: ietf@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id EB7E512EACD for <ietf@ietfa.amsl.com>; Fri, 21 Apr 2017 11:35:32 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.698
X-Spam-Level:
X-Spam-Status: No, score=-1.698 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, FREEMAIL_FORGED_FROMDOMAIN=0.199, FREEMAIL_FROM=0.001, HEADER_FROM_DIFFERENT_DOMAINS=0.001, HTML_MESSAGE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=no autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=gmail.com
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id QSJZI6CH9KNN for <ietf@ietfa.amsl.com>; Fri, 21 Apr 2017 11:35:31 -0700 (PDT)
Received: from mail-oi0-x229.google.com (mail-oi0-x229.google.com [IPv6:2607:f8b0:4003:c06::229]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 7EC4F12EACC for <ietf@ietf.org>; Fri, 21 Apr 2017 11:35:31 -0700 (PDT)
Received: by mail-oi0-x229.google.com with SMTP id j201so107005795oih.2 for <ietf@ietf.org>; Fri, 21 Apr 2017 11:35:31 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:sender:in-reply-to:references:from:date:message-id :subject:to:cc; bh=H0rDGralMqHwCrucQz8AKdT1i4nL09X4E+WvfRAMP64=; b=Z+rFd3Ui3QYWSot+zSB6Ow4tJlVO5UbklPyqlnkkgL079zpoFA3yEnejCs5fSan0ET dOkuA7KVh3p5vjkanbk/RShz28W2OIqFulNTnkpmJ7Gv2aXjCTy33+ZRWA6slOIwOhSf L+gx1OCINYCp9pUc5pvC+YHWT4PSYOfQIL4pqWPwzU5zLfAKolOyRQaQnAfOaT36PZal C72X+GEKM0vGdOsySqxO9tmOEpsxPs+95ke2RtFHIlNUhgG+czgyEIJ0FvP8g9wr+5I9 TnbLKdBK+kvCbawLW1k2TOJmoVbmfFyHQi6W6ee29AKwmg2CaHSqReSZOp2L9Ck8rkUV ezFQ==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:sender:in-reply-to:references:from :date:message-id:subject:to:cc; bh=H0rDGralMqHwCrucQz8AKdT1i4nL09X4E+WvfRAMP64=; b=o9yJXpHIofRPgPH9kGvO0MGTcse+3OMIWcDV7pjOr/xqCzd+PRGz/fVlYYNglqykx2 kiVyKJAgZhycTDIbKuWxcKae8G+BYH32hySOTwWk4gPeWv3xLmjkfw/IEcu4Fifm9p9r Rp7k6+vgXI9xUIdYJBj71C88/XIKWIeJZJE4SJeIIBEJ5uRNTP5a/rWfObiMSQU+phe9 Si3pg4eAvY755UD4UekqHxsOWQpcMrsyn6HsOu8g2X941Gmb38BglwAgtg+T8OVw8OuR hGNg1173KBWJWnsyc0vd7vKXxrdU/FPt8sNqYps3DPeAZrw2vDlhl4FcxxdIXx/JJdQx Xw6g==
X-Gm-Message-State: AN3rC/4UMv/dFGASEKZSmSEF1wee66w+M9nsyCGQNxOR5jYj8mZ4pMKC 0K1dLT0Dy6IPntWBHvhjypLp5zN3+w==
X-Received: by 10.202.178.85 with SMTP id b82mr8617364oif.151.1492799730929; Fri, 21 Apr 2017 11:35:30 -0700 (PDT)
MIME-Version: 1.0
Sender: hallam@gmail.com
Received: by 10.157.22.175 with HTTP; Fri, 21 Apr 2017 11:35:30 -0700 (PDT)
In-Reply-To: <b0f0362a-cb46-79b6-b22b-ab2baaa69327@isi.edu>
References: <CAMm+Lwi_jU6gjdtdM6a2n_9_89tUvWBNXxnMtSjTEA++h1D4Ew@mail.gmail.com> <e0a43370-751f-808c-3719-9716f9cd57d1@isi.edu> <B990A5A4-D62B-4E10-9FF7-7BA4377C0958@frobbit.se> <7bc1a350-549c-c649-81c6-bcd19cff36d7@cisco.com> <B2E6846E-F25B-4792-8E13-B5D898B67223@frobbit.se> <9f719b6a-f3c0-ef98-1636-86e84106e366@cisco.com> <16db07fe-acc5-d178-b56c-755c3cf70680@cs.ucla.edu> <CAMm+LwjQ_kaSBzcJhem5CbPLvMCAJRFnRpqJgu8SFTTQpt4bzQ@mail.gmail.com> <20170418222004.GB2856@localhost> <CAMm+LwgRegXgM3TqRJW_jfv+S6GrJ5RqJkpfaX0xQ0M7ZO_gPA@mail.gmail.com> <20170421172626.GG2856@localhost> <b0f0362a-cb46-79b6-b22b-ab2baaa69327@isi.edu>
From: Phillip Hallam-Baker <phill@hallambaker.com>
Date: Fri, 21 Apr 2017 14:35:30 -0400
X-Google-Sender-Auth: 6iRIKfQ1BZ7exaSMRsAdcGhGk6M
Message-ID: <CAMm+Lwjnrj43sN6rU-6Zf_PJAfyobeLHUtsh63G7sW0-5LH3tQ@mail.gmail.com>
Subject: Re: Predictable Internet Time
To: Joe Touch <touch@isi.edu>
Cc: Nico Williams <nico@cryptonector.com>, Paul Eggert <eggert@cs.ucla.edu>, IETF Discussion Mailing List <ietf@ietf.org>, =?UTF-8?B?UGF0cmlrIEbDpGx0c3Ryw7Zt?= <paf@frobbit.se>
Content-Type: multipart/alternative; boundary=001a1146ac5eaed445054db185ab
Archived-At: <https://mailarchive.ietf.org/arch/msg/ietf/PrZTMnGhEmhGrAwM5hZaX4jBIs0>
X-BeenThere: ietf@ietf.org
X-Mailman-Version: 2.1.22
Precedence: list
List-Id: IETF-Discussion <ietf.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/ietf>, <mailto:ietf-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/ietf/>
List-Post: <mailto:ietf@ietf.org>
List-Help: <mailto:ietf-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/ietf>, <mailto:ietf-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 21 Apr 2017 18:35:33 -0000

On Fri, Apr 21, 2017 at 1:57 PM, Joe Touch <touch@isi.edu>; wrote:

>
>
> On 4/21/2017 10:26 AM, Nico Williams wrote:
> > "Internet time" (that which we use in [new] Internet protocols) should
> > just be TAI.  And every existing Internet protocol should be updated to
> > indicate which time is used in practice, UTC or TAI, regardless of what
> > was originally specified.
> I would be very glad of we defined Internet Time as TAI, but also expect
> all protocols to understand both TAI and UTC if possible.
>
> Joe
>

​To answer the issues raised:

1) POSIX already has this pretty much covered

http://pubs.opengroup.org/onlinepubs/009695399/functions/clock_getres.html​

​int clock_gettime(clockid_t *clock_id*, struct timespec **tp*);​

​So all that is required is to define clock identifiers for:

TAI (The total number of seconds elapsed since the start of the epoch)
UTC (The TAI value adjusted for UTC leap seconds, i.e. number of non leap
second seconds since the start of the epoch)
PIT (The TAI value adjusted for PIT leap seconds)

POSIX already defines constants for CLOCK_PROCESS_CPUTIME_ID, CLOCK_REALTIME


All that is needed is to define the additional ones.


​2) No I did not move the goalposts. My original proposal was to solve the
needless chaos caused be the idiotic notion of changing the definition of
time at six months notice. The stupidity of that notion should be apparent
to all.

3) Screw the astronomers. Pluto is to a planet.​