leapseconds revision 140320 
1# @(#)leapseconds	7.17
2
3# Allowance for leapseconds added to each timezone file.
4
5# The International Earth Rotation Service periodically uses leap seconds
6# to keep UTC to within 0.9 s of UT1
7# (which measures the true angular orientation of the earth in space); see
8# Terry J Quinn, The BIPM and the accurate measure of time,
9# Proc IEEE 79, 7 (July 1991), 894-905.
10# There were no leap seconds before 1972, because the official mechanism
11# accounting for the discrepancy between atomic time and the earth's rotation
12# did not exist until the early 1970s.
13
14# The correction (+ or -) is made at the given time, so lines
15# will typically look like:
16#	Leap	YEAR	MON	DAY	23:59:60	+	R/S
17# or
18#	Leap	YEAR	MON	DAY	23:59:59	-	R/S
19
20# If the leapsecond is Rolling (R) the given time is local time
21# If the leapsecond is Stationary (S) the given time is UTC
22
23# Leap	YEAR	MONTH	DAY	HH:MM:SS	CORR	R/S
24Leap	1972	Jun	30	23:59:60	+	S
25Leap	1972	Dec	31	23:59:60	+	S
26Leap	1973	Dec	31	23:59:60	+	S
27Leap	1974	Dec	31	23:59:60	+	S
28Leap	1975	Dec	31	23:59:60	+	S
29Leap	1976	Dec	31	23:59:60	+	S
30Leap	1977	Dec	31	23:59:60	+	S
31Leap	1978	Dec	31	23:59:60	+	S
32Leap	1979	Dec	31	23:59:60	+	S
33Leap	1981	Jun	30	23:59:60	+	S
34Leap	1982	Jun	30	23:59:60	+	S
35Leap	1983	Jun	30	23:59:60	+	S
36Leap	1985	Jun	30	23:59:60	+	S
37Leap	1987	Dec	31	23:59:60	+	S
38Leap	1989	Dec	31	23:59:60	+	S
39Leap	1990	Dec	31	23:59:60	+	S
40Leap	1992	Jun	30	23:59:60	+	S
41Leap	1993	Jun	30	23:59:60	+	S
42Leap	1994	Jun	30	23:59:60	+	S
43Leap	1995	Dec	31	23:59:60	+	S
44Leap	1997	Jun	30	23:59:60	+	S
45Leap	1998	Dec	31	23:59:60	+	S
46
47# 
48# 
49# 
50#      INTERNATIONAL EARTH ROTATION AND REFERENCE SYSTEMS SERVICE (IERS) 
51# 
52# SERVICE INTERNATIONAL DE LA ROTATION TERRESTRE ET DES SYSTEMES DE REFERENCE
53# 
54# SERVICE DE LA ROTATION TERRESTRE
55# OBSERVATOIRE DE PARIS                                   
56# 61, Av. de l'Observatoire 75014 PARIS (France)
57# Tel.      : 33 (0) 1 40 51 22 26
58# FAX       : 33 (0) 1 40 51 22 91
59# Internet  : services.iers@obspm.fr
60# 
61#                                                Paris, 14 January 2005
62#                                                            
63# 
64#                                                Bulletin C 29
65#                                 
66#                                                To authorities responsible
67#                                                for the measurement and 
68#                                                distribution of time
69#
70# 
71# 
72#                           INFORMATION ON UTC - TAI
73#                       
74# 
75#  NO positive leap second will be introduced at the end of June 2005.
76#  The difference between Coordinated Universal Time UTC and the 
77#  International Atomic Time TAI is :		
78# 		
79#      from 1999 January 1, 0h UTC, until further notice : UTC-TAI = -32 s
80# 
81#  Leap seconds can be introduced in UTC at the end of the months of December 
82#  or June,  depending on the evolution of UT1-TAI. Bulletin C is mailed every  
83#  six months, either to announce a time step in UTC, or to confirm that there 
84#  will be no time step at the next possible date.
85# 
86# 
87#                                            Daniel GAMBIS
88#                                            Director			
89#                                            Earth Orientation Center of IERS
90#                                            Observatoire de Paris, France
91# 
92