Re: [Ntp] Antw: Re: Finding leap-seconds.list

[Warner Losh <[e-mail]>]

On Mon, Nov 12, 2018 at 4:34 AM Ulrich Windl <
[e-mail]> wrote:

> >>> Paul Eggert <[e-mail]> schrieb am 08.11.2018 um 22:39 in
> Nachricht
> <[e-mail]>:
> > On 11/7/18 6:49 PM, Thomas Peterson wrote:
> >> * The IETF ceases to host unpacked versions of tzdb
> >
> > I'm not sure exactly what is being proposed here. That being said, the
> > tzdb distribution <https://www.iana.org/time‑zones> is not going to
> > remove the leap‑seconds.list file. That file is used by tzdb itself and
> > (like it or not) many downstream packages depend on it. Whatever problem
> > you're trying to solve, removing leap‑seconds.list can't be part of the
> > solution.
>
> So if TZ data depend on the leapsecond list, the previous discussion on
> whether the TZ data wil be updated frequently enough should be solved: In
> my
> view of things new TZ data should be made availale whenever a new
> leapsecond
> file is available (or at least significantly before the last one expires).
>

I think the probability of that is approaching 1.0

Let's look at the timeline...

First week or so in January Bulletin C comes out
By Feb 1 new leap file that expires December-ish (it's technically valid
until Dec 31 23:59:58, but the practice has been to expire a bit before
then, IIRC, December 1st).
Then July comes around and we do it again: by august 1st a new leap file is
available, expiring June 1.

So worst case we have a 4 month window. If a TZDB release were done the day
before a new leap file, you'd have 4 months to do another release to be
"just in time".

Going back to 2010, I see the following releases: 2018g, 2012j, 2011n,
2010o (based on a quick grep of the FreeBSD vendor imports, which is
imperfect data). Each of these years shows at least monthly releases based
on the letter suffix... So there's approximately monthly releases. Worst
case, there's a 4 month window. I think we're good, and if there were a 3
month period where there were no tz changes, a special one for the new leap
file could be made either in early May or November.

Warner