Leap seconds

Paul Theodoropoulos paul at anastrophe.com
Sun Jan 14 20:46:38 UTC 2018

(I should add that I just found Bulletin C of the IERS, which one can 
subscribe to, which is an alternative to running ntpleapfetch from cron 
and instead running it manually upon an announcement of an upcoming leap 

On 1/14/2018 12:33 PM, Paul Theodoropoulos wrote:
> I am confused about leapseconds. My understanding is that this 
> confusion is not an unusual state. :)
> I'm running a Raspberry Pi 1 Raspian Stretch Stratum one server, built 
> to the spec of the Stratum-1-Microserver HOWTO on the ntpsec.org site. 
> The example/suggested ntp.conf file in that document makes no mention 
> of leapseconds. https://docs.ntpsec.org/latest/ntp_conf.html lists the 
> leapfile directive, but the ntp.conf manpage does not, only mentioning 
> it in regard to crypto functions. Though both mention the 
> leapsmearinterval directive, making clear not to run that on a public 
> server.
> Among the tools included with the NTPsec suite is ntpleapfetch, which 
> would imply (to me at least) that this is a task that should be 
> performed - though I'm also unclear on appropriate intervals. Perform 
> it one minute before midnight on June 30 and Dec 31? Check monthly on 
> the rare possibility of a leapsec at some other time?
> So, I'm confused. Should I employ ntpleapfetch from cron and include 
> the leapfile directive in my ntp.conf? Or is it best to exclude all of 
> this on a public NTPsec server?
> I'm interested in conforming to best-practices.

Paul Theodoropoulos

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