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Re: [art] Predictable Internet Time

Joe Touch <touch@isi.edu> Tue, 28 March 2017 21:40 UTC

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To: Nico Williams <nico@cryptonector.com>, Stewart Bryant <stewart.bryant@gmail.com>
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From: Joe Touch <touch@isi.edu>
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Subject: Re: [art] Predictable Internet Time
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Moving this to ART...


On 3/28/2017 10:39 AM, Nico Williams wrote:
> On Tue, Jan 03, 2017 at 06:35:03PM +0000, Stewart Bryant wrote:
>> Yes, the system should use a leap-second-free constant-duration-seconds time
>> for everything. It is only humans that need the variable jumpy version of
>> time presented to them, and that is a UI issue.
> I don't think that's quite right.
>
> Unix time is canonically a count of seconds since an epoch and admits no
> leap seconds. 

Unix time also uses a completely different definition of a "second" than
UTC.

There is no simple conversion between Unix time and UTC. Conversion
requires accurate assessment of the local Unix clock vs SI to determine
a rate conversion as well as knowing the table of leap seconds since the
Unix epoch.

> ...
> It's all about data typing. 

That is certainly one problem, but not the only one.

Joe

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