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

[Paul Eggert]

On 12/9/23 13:30, Tim Parenti wrote:
> It still falls short, though.
> of the ideal that the leap-seconds.list file itself also contain the notice
> so we (and others) don't have to duplicate it elsewhere:
> https://mm.icann.org/pipermail/tz/2017-April/024988.html
> 
> It also doesn't necessarily allay the other concerns.

Perhaps we could work around the copyright-notice problem by adding 
appropriate verbiage to the LICENSE file. This would require some 
thinking, though.

One other problem just occurred to me. Since the IERS variant of 
leap-seconds.list is not public domain, putting it into tzdata would 
contradict Internet RFC 6557 section 7 "Data Ownership"[1], which says 
that tzdata is public domain and therefore is exempt from a bunch of 
rules that I'm not familiar with and would rather not become expert in 
if I can avoid it. I suppose this could be worked around by writing a 
new RFC that addresses this issue but that'd surely be a good bit of 
work in its own right.

For now, I expect we're better off sticking with the NIST variant since 
it's public domain. If NIST stops distributing their variant then it 
might even be better for us to distribute just the *data* (which are 
identical in the two variants - they differ only in comments). We could 
do that by removing comments and recalculating the checksum as needed. 
Although I wouldn't like this solution, that's often the case when 
lawyers are involved....

[1]: https://datatracker.ietf.org/doc/html/rfc6557#section-7