# @(#)leapseconds	8.1

# Allowance for leapseconds added to each timezone file.

# The International Earth Rotation Service periodically uses leap seconds

# to keep UTC to within 0.9 s of UT1

# (which measures the true angular orientation of the earth in space); see

# Terry J Quinn, The BIPM and the accurate measure of time,

# Proc IEEE 79, 7 (July 1991), 894-905.

# There were no leap seconds before 1972, because the official mechanism

# accounting for the discrepancy between atomic time and the earth's rotation

# did not exist until the early 1970s.

# The correction (+ or -) is made at the given time, so lines

# will typically look like:

#	Leap	YEAR	MON	DAY	23:59:60	+	R/S

# or

#	Leap	YEAR	MON	DAY	23:59:59	-	R/S

# If the leapsecond is Rolling (R) the given time is local time

# If the leapsecond is Stationary (S) the given time is UTC

# Leap	YEAR	MONTH	DAY	HH:MM:SS	CORR	R/S

Leap	1972	Jun	30	23:59:60	+	S

Leap	1972	Dec	31	23:59:60	+	S

Leap	1973	Dec	31	23:59:60	+	S

Leap	1974	Dec	31	23:59:60	+	S

Leap	1975	Dec	31	23:59:60	+	S

Leap	1976	Dec	31	23:59:60	+	S

Leap	1977	Dec	31	23:59:60	+	S

Leap	1978	Dec	31	23:59:60	+	S

Leap	1979	Dec	31	23:59:60	+	S

Leap	1981	Jun	30	23:59:60	+	S

Leap	1982	Jun	30	23:59:60	+	S

Leap	1983	Jun	30	23:59:60	+	S

Leap	1985	Jun	30	23:59:60	+	S

Leap	1987	Dec	31	23:59:60	+	S

Leap	1989	Dec	31	23:59:60	+	S

Leap	1990	Dec	31	23:59:60	+	S

Leap	1992	Jun	30	23:59:60	+	S

Leap	1993	Jun	30	23:59:60	+	S

Leap	1994	Jun	30	23:59:60	+	S

Leap	1995	Dec	31	23:59:60	+	S

Leap	1997	Jun	30	23:59:60	+	S

Leap	1998	Dec	31	23:59:60	+	S

Leap	2005	Dec	31	23:59:60	+	S

#	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

# ...

# 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