[tz] leapseconds.awk, LEAP directives and references

Chris Woodbury tzocd at yahoo.com
Fri Apr 7 04:28:01 UTC 2017

Re: copyrighting and leap source information
>On Tuesday, April 4, 2017 6:33 PM, Paul Eggert <eggert at cs.ucla.edu> wrote:

>>On 04/04/2017 09:02 AM, Chris Woodbury via tz wrote:
>> I reviewed the C code and, it seems to me, the transaction
>> added should actually be for the second before, 23:59:58,
>> as the transaction itself causes 23:59:59 to be skippedaltogether.

>Perhaps Arthur David Olson or Bradley White can take a look at this, as 
>they're the leap second gurus for tz. I've never tested negative leap 

Thanks, Bradley White answered directly.  (Previous post)

>> Also, I've an AWK script that uses the IERS file Leap_Seconds.dat

>> rather than the NIST leap-seconds.list file.
>Although that would be a better technical solution, in the past we've 
>shied away from it because the IERS file is copyrighted and we and we 
>and our downstream users don't clearly have permissions to copy and 
>redistribute it.

Where it the copyright notice to which you refer above?  

Yes, IERS has copyright notices on their web pages at IERS.Org.  It says:

© 2013 - Federal Agency for Cartography and Geodesy. All rights Reserved
The information we are discussing is distributed from the Paris Observatory's

IERS FTP site and is there to fulfill BIPM's various treaty obligations to
signatories (the U.S. being one).   I have found no files, anywhere in the
<ftp://hpiers.obspm.fr/iers> directory tree, having a copyright notice.

I'll call them and ask explicitly if you think it's necessary.  Do you need
a disclaimer in writing?  (I suspect they'll think the treaties are enough.)

I no more want to burn my paws over copyrighting than you, Paul.   While
I've not inquired of my attorney in this exact case; I've gone over
copyrighting enough for my own work to have an understanding of the basic

BIPM/IERS/EOC is a world standards AND treaty organization.   The *information*
it provides HAS to be public domain.   (Imagine licensing the meter.   They're
the same, exact, crew.)   The question is really whether their comments are in
the public domain.   I would humbly suggest that that would require an explicit
copyright statement.   There simply is none, anywhere.

>> USNO MAIA also has straight list of leap-seconds in a different format.
>> <http://maia.usno.navy.mil/ser7/leapsec.dat>
>Thanks, I was not aware of this file.  It is public-domain, so perhaps we 
>could use it.  Is it updated in a timely fashion when new IERS bulletins 
>are published?  And is that web server highly available?  These have been 

>sticking points for the NIST file.
The timestamp on the file was the same day as that of the IERS Bulletin C 52.

$ date -u '+%d %b %Y %T %Z' -r bulletinc.52     # The last actual leap sec announcement

06 Jul 2016 10:07:08 UTC
$ date -u '+%d %b %Y %T %Z' -r Leap_Second.dat  # This is the IERS complete list
06 Jul 2016 11:47:48 UTC

$ date -u '+%d %b %Y %T %Z' -r leapsec.dat      # This is the USNO MAIA complete list via FTP
06 Jul 2016 12:44:51 UTC

(I downloaded these files using "curl -R" specifically to preserve their timestamps.)

As for USNO MAIA's infrastructure; I have educated guesses.  It's on the same sub-net as
Tycho.  Both Tycho and MAIA have their Point-of-Presence in Portsmouth, VA (Norfolk area)
from my point of view.

This USNO sub-net, of which Tycho and MAIA are a part, seems to be made available
outside of MILnet through a special portal (DMZ?).   They are often available when MILnet
is not.   However, you've got to have their IP addresses in your "hosts" file to use
them when the MILnet DNS servers are unavailable.   (The burden of being part of the most
attacked network on the planet.)  The "curl" RC of 6 (can't resolve host) clued me in to
the USNO's DNS servers NOT being available being the cause of my access failures.

I will note that I've NEVER had FTP nor HTTP timeouts going to the MAIA site (as I have
often had with Tycho) except when MILnet (and their DNS) was unavailable.  Nor, for that
matter, have I ever had problems getting to hpiers.opspm.fr either.  (Other OBSPM sites
(ftp.obspm.fr) *do* seem to have a problem with being too busy.)

The NIST access problem you've experienced *may* have been somewhat ameliorated recently.
The leap-seconds.list file is no longer available via time.nist.gov.  It is now at
ftp://ftp.nist.gov/pub/time.  It doesn't seem to be as busy as the round-robin time.nist.gov
hosts were (of which about a third didn't run FTP servers).  The leap-seconds.list source,
Dr. Lavine's ftp://utcnist{,2}.colorado.edu/pub, are still busy but accessible.  The latest
leap-seconds.list change was a bit confusing as Dr. Levine changed the expiration timestamp (#$)

but not the update time (#@) (which would have changed the name of the file, too).  If he had,
it would have been leap-seconds.3695414400 (#h 2e31582c a77e52e1 791cba06 76087c21 92b019b2).


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