leapseconds revision 86222 
1# @(#)leapseconds	7.14
2
3# $FreeBSD: head/share/zoneinfo/leapseconds 86222 2001-11-09 19:17:59Z wollman $
4
5# Allowance for leapseconds added to each timezone file.
6
7# The International Earth Rotation Service periodically uses leap seconds
8# to keep UTC to within 0.9 s of UT1
9# (which measures the true angular orientation of the earth in space); see
10# Terry J Quinn, The BIPM and the accurate measure of time,
11# Proc IEEE 79, 7 (July 1991), 894-905.
12# There were no leap seconds before 1972, because the official mechanism
13# accounting for the discrepancy between atomic time and the earth's rotation
14# did not exist until the early 1970s.
15
16# The correction (+ or -) is made at the given time, so lines
17# will typically look like:
18#	Leap	YEAR	MON	DAY	23:59:60	+	R/S
19# or
20#	Leap	YEAR	MON	DAY	23:59:59	-	R/S
21
22# If the leapsecond is Rolling (R) the given time is local time
23# If the leapsecond is Stationary (S) the given time is UTC
24
25# Leap	YEAR	MONTH	DAY	HH:MM:SS	CORR	R/S
26Leap	1972	Jun	30	23:59:60	+	S
27Leap	1972	Dec	31	23:59:60	+	S
28Leap	1973	Dec	31	23:59:60	+	S
29Leap	1974	Dec	31	23:59:60	+	S
30Leap	1975	Dec	31	23:59:60	+	S
31Leap	1976	Dec	31	23:59:60	+	S
32Leap	1977	Dec	31	23:59:60	+	S
33Leap	1978	Dec	31	23:59:60	+	S
34Leap	1979	Dec	31	23:59:60	+	S
35Leap	1981	Jun	30	23:59:60	+	S
36Leap	1982	Jun	30	23:59:60	+	S
37Leap	1983	Jun	30	23:59:60	+	S
38Leap	1985	Jun	30	23:59:60	+	S
39Leap	1987	Dec	31	23:59:60	+	S
40Leap	1989	Dec	31	23:59:60	+	S
41Leap	1990	Dec	31	23:59:60	+	S
42Leap	1992	Jun	30	23:59:60	+	S
43Leap	1993	Jun	30	23:59:60	+	S
44Leap	1994	Jun	30	23:59:60	+	S
45Leap	1995	Dec	31	23:59:60	+	S
46Leap	1997	Jun	30	23:59:60	+	S
47Leap	1998	Dec	31	23:59:60	+	S
48
49#                  INTERNATIONAL EARTH ROTATION SERVICE (IERS)
50#   	       SERVICE INTERNATIONAL DE LA ROTATION TERRESTRE
51# 
52# SERVICE DE LA ROTATION TERRESTRE
53# OBSERVATOIRE DE PARIS
54# 61, Av. de l'Observatoire 75014 PARIS (France)
55# Tel.      : 33 (0) 1 40 51 22 26
56# FAX       : 33 (0) 1 40 51 22 91
57# Internet  : iers@obspm.fr
58# 
59#                                                Paris, 25 June 2001
60# 
61#                                                Bulletin C 22
62# 
63#                                                To authorities responsible
64#                                                for the measurement and
65#                                                distribution of time
66# 
67#                           INFORMATION ON UTC - TAI
68# 
69#  NO positive leap second will be introduced at the end of December 2001.
70#  The difference between UTC and the International Atomic Time TAI is :
71# 
72#      from 1999 January 1, 0h UTC, until further notice : UTC-TAI = -32 s
73# 
74#  Leap seconds can be introduced in UTC at the end of the months of December
75#  or June,  depending on the evolution of UT1-TAI. Bulletin C is mailed every
76#  six months, either to announce a time step in UTC, or to confirm that there
77#  will be no time step at the next possible date.
78# 
79#                                              Daniel GAMBIS
80#                                              Director
81#                                              Earth Orientation Center of IERS
82