On 2025-04-18 12:12 PM, Tim Parenti via tz wrote:
On Fri, 18 Apr 2025 at 04:00, Collin Funk via tz<tz@iana.org> wrote:
The generated leapseconds file mentions the data can be retrieved from
ftp.boulder.nist.gov/pub/time/leap-seconds.list, but the domain no
longer resolves.
The domain definitely still resolves:
$ digftp.boulder.nist.gov
<…snipped…>
;; ANSWER SECTION:
ftp.boulder.nist.gov. 300 IN A 132.163.4.45
<…snipped…>
An ftp client can still connect to this server and the relevant file is
still present:
$ ftpftp.boulder.nist.gov
Trying 132.163.4.45:21 ...
Connected toftp.boulder.nist.gov.
220 ProFTPD Server (NIST Time/Frequency Division FTP Server)
[::ffff:10.88.0.2]
Name (ftp.boulder.nist.gov:root): anonymous
331 Anonymous login ok, send your complete email address as your password
Password:
<…snipped…>
230 Anonymous access granted, restrictions apply
Remote system type is UNIX.
Using binary mode to transfer files.
ftp> ls pub/time/leap-seconds.list
229 Entering Extended Passive Mode (|||20091|)
150 Opening ASCII mode data connection for file list
-rwxr-xr-x 1 ftp ftp 10921 Feb 7 2024
pub/time/leap-seconds.list
226 Transfer complete
Indeed, you can generally skip these steps by using something like `curl`:
curlftp://ftp.boulder.nist.gov/pub/time/leap-seconds.list >
leap-seconds-NIST.list
However, I note that the version of the file which is present on the NIST
server is dated 2024-02-07 and has an expiration date of 2024-12-28. It's
not clear whether this is just another temporary lapse on NIST's end or
whether this points to a more recent deprecation of service of some sort.
For what it's worth, other files on that server, namely in the wwvb
directory, do appear to still be receiving (automated) updates.
Perhaps part of the confusion here is that a URL with the ftp:// protocol
can no longer be naïvely pasted into a modern web browser. As FTP usage
declined steeply over the last decade or two, browsers have broadly dropped
their once-native support for the FTP protocol. For example, Firefox 90
and Chrome 95 completely removed this functionality back in July and
October 2021, respectively. In both cases, such functionality had even by
that point already been deprecated, disabled-by-default, and on the
chopping block for several years:
https://blog.mozilla.org/security/2021/07/20/stopping-ftp-support-in-firefox-90/
https://www.theregister.com/2021/07/21/firefox_ends_ftp_support/
https://developer.chrome.com/blog/deps-rems-95
https://www.theregister.com/2021/10/20/ftp_chrome_95/
We have many other FTP references throughout tzdata, so as long as
useful data is still being served (which may indeed be an open question),
it doesn't make any more sense to drop reference to this one than any of
the others.
--
Tim Parenti
I can read ftp.boulder.nist.gov/pub/time/leap-seconds.list with an FTP
client app.
As you say that version says:
# Updated through IERS Bulletin C67
# File expires on: 28 December 2024
But note what you find at IANA:
https://data.iana.org/time-zones/data/leap-seconds.list
which says:
Updated through IERS Bulletin C
(https://hpiers.obspm.fr/iers/bul/bulc/bulletinc.dat)
File expires on 28 December 2025
So seems somebody updated that one from some other source? Such as:
https://hpiers.obspm.fr/iers/bul/bulc/ntp/leap-seconds.list
This matches the file at IANA.
