1# <pre> 2# @(#)leapseconds 8.9 3# This file is in the public domain, so clarified as of 4# 2009-05-17 by Arthur David Olson. 5 6# Allowance for leapseconds added to each timezone file. 7 8# The International Earth Rotation Service periodically uses leap seconds 9# to keep UTC to within 0.9 s of UT1 10# (which measures the true angular orientation of the earth in space); see 11# Terry J Quinn, The BIPM and the accurate measure of time, 12# Proc IEEE 79, 7 (July 1991), 894-905. 13# There were no leap seconds before 1972, because the official mechanism 14# accounting for the discrepancy between atomic time and the earth's rotation 15# did not exist until the early 1970s. 16 17# The correction (+ or -) is made at the given time, so lines 18# will typically look like: 19# Leap YEAR MON DAY 23:59:60 + R/S 20# or 21# Leap YEAR MON DAY 23:59:59 - R/S 22 23# If the leapsecond is Rolling (R) the given time is local time 24# If the leapsecond is Stationary (S) the given time is UTC 25 26# Leap YEAR MONTH DAY HH:MM:SS CORR R/S 27Leap 1972 Jun 30 23:59:60 + S 28Leap 1972 Dec 31 23:59:60 + S 29Leap 1973 Dec 31 23:59:60 + S 30Leap 1974 Dec 31 23:59:60 + S 31Leap 1975 Dec 31 23:59:60 + S 32Leap 1976 Dec 31 23:59:60 + S 33Leap 1977 Dec 31 23:59:60 + S 34Leap 1978 Dec 31 23:59:60 + S 35Leap 1979 Dec 31 23:59:60 + S 36Leap 1981 Jun 30 23:59:60 + S 37Leap 1982 Jun 30 23:59:60 + S 38Leap 1983 Jun 30 23:59:60 + S 39Leap 1985 Jun 30 23:59:60 + S 40Leap 1987 Dec 31 23:59:60 + S 41Leap 1989 Dec 31 23:59:60 + S 42Leap 1990 Dec 31 23:59:60 + S 43Leap 1992 Jun 30 23:59:60 + S 44Leap 1993 Jun 30 23:59:60 + S 45Leap 1994 Jun 30 23:59:60 + S 46Leap 1995 Dec 31 23:59:60 + S 47Leap 1997 Jun 30 23:59:60 + S 48Leap 1998 Dec 31 23:59:60 + S 49Leap 2005 Dec 31 23:59:60 + S 50Leap 2008 Dec 31 23:59:60 + S 51 52# INTERNATIONAL EARTH ROTATION AND REFERENCE SYSTEMS SERVICE (IERS) 53# 54# SERVICE INTERNATIONAL DE LA ROTATION TERRESTRE ET DES SYSTEMES DE REFERENCE 55# 56# SERVICE DE LA ROTATION TERRESTRE 57# OBSERVATOIRE DE PARIS 58# 61, Av. de l'Observatoire 75014 PARIS (France) 59# Tel. : 33 (0) 1 40 51 22 26 60# FAX : 33 (0) 1 40 51 22 91 61# Internet : services.iers@obspm.fr 62# 63# Paris, 4 July 2009 64# 65# Bulletin C 38 66# 67# To authorities responsible 68# for the measurement and 69# distribution of time 70# 71# INFORMATION ON UTC - TAI 72# 73# NO positive leap second will be introduced at the end of December 2009. 74# The difference between Coordinated Universal Time UTC and the 75# International Atomic Time TAI is : 76# 77# from 2009 January 1, 0h UTC, until further notice : UTC-TAI = -34 s 78# 79# Leap seconds can be introduced in UTC at the end of the months of December 80# or June, depending on the evolution of UT1-TAI. Bulletin C is mailed every 81# six months, either to announce a time step in UTC, or to confirm that there 82# will be no time step at the next possible date. 83# 84# Daniel GAMBIS 85# Director 86# Earth Orientation Center of IERS 87# Observatoire de Paris, France 88