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From: imp at bsdimp.com (Warner Losh)
Subject: [COFF] Manipulating time_t values (was: Unix half-billion years old 1985)
Date: Mon, 4 Nov 2019 20:07:07 -0700	[thread overview]
Message-ID: <CANCZdfq-+7dXDWS819GjKx4BFdhhdcgcWF5CsXNukWVqjDCiaA@mail.gmail.com> (raw)
In-Reply-To: <20191104235025.C0548156E80B@mail.bitblocks.com>

On Mon, Nov 4, 2019, 5:00 PM Bakul Shah <bakul at bitblocks.com> wrote:

> On Tue, 05 Nov 2019 10:00:55 +1100 Greg 'groggy' Lehey <grog at lemis.com>
> wrote:
> >
> > [Moved to COFF]
> >
> > On Monday,  4 November 2019 at 16:59:22 -0500, John P. Linderman wrote:
> > > I wrote a near-trivial "timestamp" command to make it easier to do time
> > > arithmetic
> > >
> > > TZ=udt timestamp
> > > 119 11 04 21 50 06 18204 1572904206 Mon Nov  4 21:50:06 2019
> > > TZ=udt timestamp 0
> > > 70 01 01 00 00 00 0 0 Thu Jan  1 00:00:00 1970
> > > ...
> >
> > FreeBSD has this functionality in date(1):
> >
> >  TZ=UTC date -r 500000000
> >  Tue  5 Nov 1985 00:53:20 UTC
> >  TZ=UTC date -r 1500000000
> >  Fri 14 Jul 2017 02:40:00 UTC
>
> Shouldn't that be
>     Tue  5 Nov 1985 00:52:57 UTC
>     Fri 14 Jul 2017 02:39:23 UTC
> given that this is UTC (which is 37 seconds behind TAI)?
>

The delta was closer to 18 in 1985 and 36 on 2017. But that doesn't matter.

Sorry :-)
>

No. POSIX says leap seconds do not exist for the computation of these
numbers. Greg's numbers are POSIXly correct.

Warner

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  reply	other threads:[~2019-11-05  3:07 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <alpine.BSF.2.21.9999.1911050805570.11612@aneurin.horsfall.org>
     [not found] ` <alpine.BSF.2.21.9999.1911050809230.11612@aneurin.horsfall.org>
     [not found]   ` <CAC0cEp_WX_aXRWnHcat8ZYbdvf8aeudGoU_SA2+Nj0Nc7v9sKA@mail.gmail.com>
2019-11-04 23:00     ` grog
2019-11-04 23:50       ` bakul
2019-11-05  3:07         ` imp [this message]
2019-11-05 11:13           ` dot

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