[tz] leap_second.list not updated after latest IERS Bulletin C

Brian Inglis Brian.Inglis at Shaw.ca
Fri Dec 8 21:50:00 UTC 2023

On 2023-12-08 12:58, Brooks Harris via tz wrote:
> On 12/7/2023 9:29 PM, Paul Eggert via tz wrote:
>> On 12/7/23 13:21, Geert Hendrickx wrote:
>>> NTPsec logs the following at startup:
>>> CLOCK: leapsecond file ('/etc/ntp/leap-seconds.list'): good hash signature
>>> CLOCK: leapsecond file ('/etc/ntp/leap-seconds.list'): loaded, 
>>> expire=2024-06-28T00:00Z last=2017-01-01T00:00Z ofs=37
>>> So I *guess* (without having looked at the code) that it actually cares
>>> about the expiration date as well.
>> I think you're right NTPsec does care, though I vaguely recall that if the 
>> file has expired the only issue is an unwanted log message.
>> If people are running NTPsec and configuring it to use TZDB's 
>> leap-seconds.list, that unwanted log message could be an issue. I just now 
>> checked the NTPsec source code, though, and by default it uses this URL:
>> https://www.ietf.org/timezones/data/leap-seconds.list
>> which hasn't worked in a while; the contents are simply "ietf.org is no longer 
>> serving this file." So it may be that we don't need to issue a new TZDB 
>> release merely because 2023c's leap-seconds.list will be out-of-date soon.
>>> (but we periodically download it from IERS, not from TZ)
>> In that case your setup is OK as-is, though we may still need to hear from 
>> other people to see whether they're relying on the TZDB copy of 
>> leap-seconds.list.
>> TZDB uses the NIST version of leap-seconds.list rather than the IERS version, 
>> as the NIST version is clearly public domain and so this way we don't have to 
>> worry about copyright issues. However, the IERS version should work fine with 
>> either NTPsec or with other downstream uses, such as TZDB itself (that is, if 
>> you're not worried about copyright).
> In my opinion TzDb should update the leap-seconds.list date and issue a TzDb 
> release because there's no telling who might be using it and perhaps relying on 
> the expiry date.
> The current expiry date at https://ftp.iana.org/tz/tzdb-2023c/leap-seconds.list is
> #    File expires on:  28 December 2023
> The current expiry date at ftp://ftp.boulder.nist.gov/pub/time/leap-seconds.list is
> #    File expires on:  28 June 2024
> There are other sources at IERS besides Bulletin C. In my development work I've 
> been using:
> https://hpiers.obspm.fr/eoppc/bul/bulc/Leap_Second_History.dat
> This file has a different form, using MJD rather than "number of seconds since 1 
> January 1900, 00:00:00".
> Note that, as I understand it, Bulletin  C is the only official "product" of the 
> IERS. But this Leap_Second_History.dat file has been being issued and maintained 
> for years.
> I cannot comment expertly on "copyright", but it seems to me anything from IERS 
> must be public domain, isn't it? How is it not?

FR and many EU countries are on the Napoleonic era Civil Code which does not 
recognize the public domain and asserts copyrights and many personal and moral 
rights over documents and data and database rights over data and compilations;
I believe that may also be substantially true in the English common law UK 
(although the KJV Bible rights are held in perpetuity by the Crown, and "Peter 
Pan" was granted in perpetuity to Great Ormond Street Childrens' Hospital, 
although expiring in the US this month):
in some South American and African countries breach of copyright and other 
rights may be in the Criminal Code, payments for works including cultural, 
traditional, and public domain works may be required, may be perpetual, may be 
payable to governments rather than creators, and may require no authorization!

How this applies to foreign works is idiosyncratic: in some countries it is 
possible that a tax^Wroyalty is payable for use of the tzdb.

Take care. Thanks, Brian Inglis              Calgary, Alberta, Canada

La perfection est atteinte                   Perfection is achieved
non pas lorsqu'il n'y a plus rien à ajouter  not when there is no more to add
mais lorsqu'il n'y a plus rien à retirer     but when there is no more to cut
                                 -- Antoine de Saint-Exupéry

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