Richard Laager rlaager at wiktel.com
Tue Mar 20 19:43:43 UTC 2018

On 03/20/2018 02:30 PM, Richard Laager via devel wrote:
> Is the leap smearing in NTPsec compatible with the new Google leap
> smear: https://developers.google.com/time/smear
> Specifically,
> 1) Is it linear (not cosine)?

Upon a second pass, I found this in the code. I see it was changed from
cosine to linear.

See check_leapsec() in ntpd/ntp_timer.c.

> 2) Is it noon to noon UTC?
I'm still concerned about this one. In the same function, we have this:

leap_smear.interval = leap_smear_intv;
leap_smear.intv_end = lsdata.ttime;
leap_smear.intv_start = leap_smear.intv_end - leap_smear.interval;

Is this smearing over the interval (e.g. 24 hours) _before_ the leap
second, as opposed to _centered on_ the leap second (which is what
Google does)?


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