leapseconds revision 75267 
1# @(#)leapseconds	7.13
2
3# $FreeBSD: head/share/zoneinfo/leapseconds 75267 2001-04-06 16:46:52Z 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# INTERNATIONAL EARTH ROTATION SERVICE (IERS)
49# SERVICE INTERNATIONAL DE LA ROTATION TERRESTRE
50# 
51# SERVICE DE LA ROTATION TERRESTRE
52# OBSERVATOIRE DE PARIS
53# 61, Av. de l'Observatoire 75014 PARIS (France)
54# Tel.      : 33 (0) 1 40 51 22 26
55# FAX       : 33 (0) 1 40 51 22 91
56# Internet  : iers@obspm.fr
57# 
58# Paris, 11 January 2001
59# 
60# Bulletin C 21
61# 
62# To authorities responsible for the measurement and distribution of time
63# 
64# INFORMATION ON UTC - TAI
65# 
66# NO positive leap second will be introduced at the end of June 2001.
67