We need to test leap smearing :)

Gary E. Miller gem at rellim.com
Fri Dec 23 01:49:45 UTC 2022

Yo Fred!

On Thu, 22 Dec 2022 17:00:37 -0800 (PST)
Fred Wright via devel <devel at ntpsec.org> wrote:

> On Wed, 21 Dec 2022, Hal Murray via devel wrote:
> > Google says:
> >  https://developers.google.com/time/smear
> >  We encourage anyone smearing leap seconds to use a 24-hour linear
> > smear from noon to noon UTC.
> >
> > There were earlier versions which did sine rather than linear.  
> Hmm.  I don't recall any nonlinear version (and I presume you meant
> raised cosine rather than sine), but I do recall that Google's smear
> interval was originally 20 hours, not 24.  If you make it 24 hours,
> there's the question of whether that means 86400 seconds or 86401. :-)

There are many strange smearing schemees.  From a few hours to 48 hours. 

Google: On Feb 15 Google said they smear linear, over 20 hours,
centered on the leap second.

Previously Google said this:


    lie(t) = (1.0 - cos(pi * t / w)) / 2.0 

AWS smears linear for the 24 hours preceeding the leap second.

Some versions of NTP and chronyd, can ignore the leap second, then slew
the system clock to catch up:


And of course:

The madness goes on, the only way to win the game is not to play.

Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
	gem at rellim.com  Tel:+1 541 382 8588

	    Veritas liberabit vos. -- Quid est veritas?
    "If you can't measure it, you can't improve it." - Lord Kelvin
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