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Re: [Ntp] Antw: [EXT] Re: CLOCK_TAI (was NTPv5: big picture)

James <james.ietf@gmail.com> Fri, 08 January 2021 23:04 UTC

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Date: Fri, 08 Jan 2021 23:04:43 +0000
From: James <james.ietf@gmail.com>
To: Hal Murray <hmurray@megapathdsl.net>
Cc: Martin Burnicki <martin.burnicki=40meinberg.de@dmarc.ietf.org>, "ntp@ietf.org" <ntp@ietf.org>
Message-ID: <20210108230443.oocb27ymuae64qz2@1aca054cd561>
References: <martin.burnicki=40meinberg.de@dmarc.ietf.org> <617faa37-0edb-4e48-b4eb-c0bf2d57b809@meinberg.de> <20210108160337.545C940605C@ip-64-139-1-69.sjc.megapath.net>
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Subject: Re: [Ntp] Antw: [EXT] Re: CLOCK_TAI (was NTPv5: big picture)
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They have, however they take different approaches to the smear:

* Google[1] and Amazon Web Services[2] use a linear smear that runs over
  ~48 hours, starting 24 hours before, and ending 24 hours afterwards
* Bloomberg[3] appears to not apply the leap second (59 -> 00) but then
  smears over the subsequent 2000 seconds.

- J

1: https://developers.google.com/time/smear
2: https://aws.amazon.com/blogs/aws/look-before-you-leap-the-coming-leap-second-and-aws/
3: https://data.bloomberglp.com/professional/sites/4/Bloomberg-Leap-Second_December-2016.pdf

On Fri, Jan 08, 2021 at 08:03:37AM -0800, Hal Murray wrote:
> 
> martin.burnicki=40meinberg.de@dmarc.ietf.org said:
> > Beside this, there are lots of potential problems due to different shapes and
> > intervals for the smearing.
> 
> Is that a real problem?  I thought that the big boys had agreed on linear over 
> 24 hours centered on the leap.
> 
> -- 
> These are my opinions.  I hate spam.
> 
> 
> 
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