Add new upcoming leap second - Dec. 2016

[shunter]

https://datacenter.iers.org/eop/-/somos/5Rgv/latest/16

     INTERNATIONAL EARTH ROTATION AND REFERENCE SYSTEMS SERVICE (IERS) 

SERVICE INTERNATIONAL DE LA ROTATION TERRESTRE ET DES SYSTEMES DE REFERENCE

SERVICE DE LA ROTATION TERRESTRE DE L'IERS
OBSERVATOIRE DE PARIS                                   
61, Av. de l'Observatoire 75014 PARIS (France)
Tel.      : +33 1 40 51 23 35
e-mail    : services.iers@obspm.fr
http://hpiers.obspm.fr/eop-pc


                                              Paris, 6 July 2016

                                              Bulletin C 52

 To authorities responsible for the measurement and distribution of time                                         


                                   UTC TIME STEP
                            on the 1st of January 2017


 A positive leap second will be introduced at the end of December 2016.
 The sequence of dates of the UTC second markers will be:       

                          2016 December 31, 23h 59m 59s
                          2016 December 31, 23h 59m 60s
                          2017 January   1,  0h  0m  0s

 The difference between UTC and the International Atomic Time TAI is:

  from 2015 July 1, 0h UTC, to 2017 January 1 0h UTC   : UTC-TAI = - 36s
  from 2017 January 1, 0h UTC, until further notice    : UTC-TAI = - 37s 



 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.


                                              Christian Bizouard
                                              Head
                                              Earth Orientation Center of IERS
                                              Observatoire de Paris, France

[pjcozzi]

Thanks @shunter, I just learned of this today too. Do you have time to open a PR with the updated leap seconds?