Long overdue! --ado -----Original Message----- From: Joseph S. Myers [mailto:jsm@polyomino.org.uk] Sent: Monday, July 04, 2005 1:25 PM To: LEAPSECS@ROM.USNO.NAVY.MIL; tz@lecserver.nci.nih.gov Subject: Bulletin C number 30 (fwd) ---------- Forwarded message ---------- Date: Mon, 4 Jul 2005 15:27:31 +0200 From: "services.iers@obspm.fr" <services.iers@obspm.fr> To: adresc1@callisto.obspm.fr Subject: Bulletin C number 30 INTERNATIONAL EARTH ROTATION AND REFERENCE SYSTEMS SERVICE (IERS) SERVICE INTERNATIONAL DE LA ROTATION TERRESTRE ET DES SYSTEMES DE REFERENCE SERVICE DE LA ROTATION TERRESTRE OBSERVATOIRE DE PARIS 61, Av. de l'Observatoire 75014 PARIS (France) Tel. : 33 (0) 1 40 51 22 26 FAX : 33 (0) 1 40 51 22 91 e-mail : services.iers@obspm.fr http://hpiers.obspm.fr/eop-pc Paris, 4 July 2005 Bulletin C 30 To authorities responsible for the measurement and distribution of time UTC TIME STEP on the 1st of January 2006 A positive leap second will be introduced at the end of December 2005. The sequence of dates of the UTC second markers will be: 2005 December 31, 23h 59m 59s 2005 December 31, 23h 59m 60s 2006 January 1, 0h 0m 0s The difference between UTC and the International Atomic Time TAI is: from 1999 January 1, 0h UTC, to 2006 January 1 0h UTC : UTC-TAI = - 32s from 2006 January 1, 0h UTC, until further notice : UTC-TAI = - 33s 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. Daniel GAMBIS Head Earth Orientation Center of IERS Observatoire de Paris, France
Daniel GAMBIS wrote:
A positive leap second will be introduced at the end of December 2005.
"Olson, Arthur David (NIH/NCI)" wrote on 2005-07-05 12:42 UTC:
Long overdue!
Not so. Daniel Gambis mentioned at a meeting in June 2003 the expectation of some people at IERS then, that there probably would not be a leap second before 2006. It seems they were wrong, but only by one second! If I naively extrapolate the recent trend at http://www.ucolick.org/~sla/leapsecs/atomic.pdf it may be quite a few years until we are going to see another one. Earth's rotation has been accellerating almost continuously since the invention of the leap second in 1972, as if our planet is keen to get at least one negative leap second in before they are abolished ... Markus http://www.mail-archive.com/leapsecs@rom.usno.navy.mil/msg00163.html http://www.cl.cam.ac.uk/~mgk25/time/leap/ -- Markus Kuhn, Computer Laboratory, University of Cambridge http://www.cl.cam.ac.uk/~mgk25/ || CB3 0FD, Great Britain
participants (2)
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Markus Kuhn -
Olson, Arthur David (NIH/NCI)