Re: NTPD leap second file

Am 28.11.23 um 11:28 schrieb Steve O'Hara-Smith:
> On Tue, 28 Nov 2023 10:33:45 +0100
> Jos Chrispijn <bsduser@cloudzeeland.nl> wrote:
> 
>> Recently I noticed this:
>>
>> fetch: https://www.ietf.org/timezones/data/leap-seconds.list: Not Found
> 
> 	Where did you notice it ?
> 
>> Looks to be an NTPD leap second file, which isn't supported by ietf.org
>> anymore.
> 
> 	I found more than I ever wanted to know about leap second files
> here:
> 
> <https://kb.meinbergglobal.com/kb/time_sync/ntp/configuration/ntp_leap_second_file>
> 
> 	It has many alternative links, it's far from clear that they have
> the same data.
> 
> 	It seems the one I currently have in /var/db expires on 20th dec -
> I'll keep an eye out for what happens.
> 

Now, the leap seconds are, AFAIK, internationally coordinated by ITU. 
Still.
So, unless the server you are fetchting from is outdated itself, they 
all should have the same data. It is an ascii file and it tells you 
inside, when it will be expiring so you can easily check it being recent.

Other than that, if yours is expired, you'll see a message being logged 
during start up of ntpd, that's probably about it.

crystal ball: If a leap second is inserted - with your list being 
expired - you may have that offset, and your ntpd will smoothly catch up 
with it rather quickly.
Should only happen at the very end of the year, if at all. I am not 
aware of the next planned leap second. But that does not mean anything, 
of course.

Oh, and, it seems, from 2035 on, leap seconds may be gone alltogether.

https://theconversation.com/its-time-out-for-leap-seconds-an-expert-explains-why-the-tiny-clock-adjustments-will-be-paused-from-2035-194922

https://earthsky.org/human-world/leap-second-june-30-december-31-why-need-controversy/

If somebody knows better, please let us know.