It appears that the IETF no longer carries the leap-seconds.list file. Both upgraded and newly-installed instances of FreeBSD are giving me warnings in /var/log/messages about my installed version's pending expiration on 12/28/23. In debugging I tried to fetch the file referenced in /etc/defaults/rc.conf directly (aka - ntp_leapfile_sources="https://www.ietf.org/timezones/data/leap-seconds.list") and instead of data I get the following: ietf.org is no longer serving this file. I've personally been able to work around it via ntp_leapfile_sources="https://hpiers.obspm.fr/iers/bul/bulc/ntp/leap-seconds.list" but wanted to alert you all so it can be updated to this or another location, ideally before expiry. Thanks for your consideration, Michael Proto
Another note, while searching for a new location I read some references that the link I provided may not work for upstream as there are questions of copyright. I tried briefly finding an HTTP/HTTPS link via public-domain through NIST but wasn't able to so just settled on the IERS version myself.
More searching, looks like there's more time than the 12/28 expiry time to resolve the issue, per https://datacenter.iers.org/data/latestVersion/bulletinC.txt: NO leap second will be introduced at the end of December 2023. The difference between Coordinated Universal Time UTC and the International Atomic Time TAI is : from 2017 January 1, 0h UTC, until further notice : UTC-TAI = -37 s Leap seconds can be introduced in UTC at the end of the months of December or June, depending on the evolution of UT1-TAI. Bulletin C is mailed every six months, either to announce a time step in UTC, or to confirm that there will be no time step at the next possible date.
One more and I'll be quiet... After more testing, this might work: ftp://ftp.boulder.nist.gov/pub/time/leap-seconds.list
Looks like this was fixed in https://cgit.freebsd.org/src/commit/libexec/rc/rc.conf?id=b1c95af45488bef649e9a84890e2414ff80b3a00
(In reply to Brad Davis from comment #4) The file on data.iana.org is not up to date.
Ok, reopen. NIST seems to be newer, indeed.
There will be no leap second introduced at the end of 2023, so there is no burning rush to update this file. The only effect of updating the file will be the silencing of the warning about its expiry on 2023-12-28. Note that ntpd uses leap-seconds.list only as a last resort. It also receives leap second information from its peers. Having said that: we should have a live upstream. The IANA upstream is live, but the file is out of date. We can't use the IERS upstream because of copyright concerns (see also the ongoing discussion on the tz@iana.org mailing list). The NIST upstream is a candidate, but it's not available over HTTP and I'm not wild about pointing to FTP in 2023. There's a discussion ongoing about an erratum for this. Marking as "in progress".
*** This bug has been marked as a duplicate of bug 275419 ***