[time-nuts] Leap second to be introduced at midnight UTC December 31 this year

Martin Burnicki martin.burnicki at burnicki.net
Tue Jul 19 09:19:32 EDT 2016

Hal Murray wrote:
> michael.cook at sfr.fr said:
>> The relevant NTP leap-seconds-list file can be downloaded with anonymous ftp
>> from the pub directory at time.nist.gov.  (The leap-seconds-list file is a
>> symbolic link to the data file leap-seconds.3676924800 in the same
>> directory. ) 
> The NIST servers at that "host" don't work very well for FTP.  That host name 
> rotates across their NTP servers and a lot of those sites don't have a FTP 
> server on that machine.
> Some of the sites work.
>   ftp://utcnist.colorado.edu/pub/
> The IETF has a copy, but it hasn't been updated yet.
>   http://www.ietf.org/timezones/data/

No, because it's extracted from the TZ database. The leap second file in
the TZ DB is only updated when the next TZ DB version is released after
a new leap second file has been released.

Just recently a patch has been submitted for the TZ DB to update the
leap second file.

> USNO has a similar version:
>   ftp://tycho.usno.navy.mil/pub/ntp/
> Sometimes it doesn't work.  ??
> Meinberg has a version:
>   http://www.meinberg.de/download/ntp/leap-seconds.list

which is a copy of the IERS file available at

I've put some information on leap second files together in a PDF:

BTW, some GPS satellites began recently to broadcast the leap second
information. The "mbgstatus" program for Meinberg PCI cards reports:

t0t: 1906|405504.0000000, A0: 0 A1: -1.77636e-15
WNlsf: 1929, DN: 7, offs: 17/18
UTC offset transition from 17s to 18s due to leap second
insertion at UTC midnight at the end of 2016-12-31.


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