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[Ntp] Leap smearing

Doug Arnold <doug.arnold@meinberg-usa.com> Thu, 10 December 2020 00:24 UTC

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From: Doug Arnold <doug.arnold@meinberg-usa.com>
To: "ntp@ietf.org" <ntp@ietf.org>
Thread-Topic: Leap smearing
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Date: Thu, 10 Dec 2020 00:24:16 +0000
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Subject: [Ntp] Leap smearing
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For those organizations who want to leap smears, ntpv5 could support them with a leap smear extension that can be applied by clients.  Smeared time = UTC + leap smear offset.

After an added leap second the leap smear offset = -1, and gradually changes to 0 over the smear interval.  The leap smear function could be a cosine function, to match the frequency at the start and end of the leap smear interval.

Smear offset = -cosine(pi t/T) -0.5, where t time since leap second event, and T is the leap period.

Note it would always be possible to determine the unsmeared UTC if needed in this approach.

Doug

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