[LEAPSECS] stale leap second information

Steve Allen sla at ucolick.org
Mon Jan 12 14:08:27 EST 2015


On Mon 2015-01-12T07:10:23 -0800, Steve Allen hath writ:
> at the moment the most reliable source
> is probably the IANA TimeZone Database
> https://www.iana.org/time-zones
> That comes with a caveat that it does not instantly respond to the
> changes, so the most recent release is 2014j from November.
> The tzdata.tar.gz contains the file
> leap-seconds.list
> That file originates from NIST and it does include an expiration data
> of June 28.

It should be the case that file is found at
ftp://time.nist.gov/pub/leap-seconds.list
as a link to a file named something like
leap-seconds.<NTPsecondCount>
But for the past many days this NIST ftp server has not responded.

It should also be the case the file is found at
ftp://tycho.usno.navy.mil/pub/ntp/
but this one is signed by a USNO employee rather than a NIST employee.
Despite what the content of the most recent file says in its
commentary, there is no link to a generic leap-seconds.list file, only
the individual NTP-stamped versions.

The leap-seconds.list file itself reveals one of the biggest problems
about the handling of leap seconds: the data are accompanied by
documentation which is descriptive rather than authoritative.
There is no place where an authoritative desciption of how things
actually work can be obtained, certainly not the ITU-R and its TF.460.

The folks behind TimeZone, Arthur David Olson, Paul Eggert, everyone
who has contributed to that, the IANA and also the leads of the IETF
tzdist initiative deserve more thanks than they will ever receive for
the effort they have put into making a robust and workable scheme out
of this inherently unreliable arena of human behavior.

--
Steve Allen                 <sla at ucolick.org>                WGS-84 (GPS)
UCO/Lick Observatory--ISB   Natural Sciences II, Room 165    Lat  +36.99855
1156 High Street            Voice: +1 831 459 3046           Lng -122.06015
Santa Cruz, CA 95064        http://www.ucolick.org/~sla/     Hgt +250 m


More information about the LEAPSECS mailing list