leapseconds revision 147771 
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
46Leap	2005	Dec	31	23:59:60	+	S
47
48# 
49# 
50# 
51#      INTERNATIONAL EARTH ROTATION AND REFERENCE SYSTEMS SERVICE (IERS) 
52# 
53# SERVICE INTERNATIONAL DE LA ROTATION TERRESTRE ET DES SYSTEMES DE REFERENCE
54# 
55# SERVICE DE LA ROTATION TERRESTRE
56# OBSERVATOIRE DE PARIS                                   
57# 61, Av. de l'Observatoire 75014 PARIS (France)
58# Tel.      : 33 (0) 1 40 51 22 26
59# FAX       : 33 (0) 1 40 51 22 91
60# e-mail    : services.iers@obspm.fr
61# http://hpiers.obspm.fr/eop-pc
62# 
63#                                               Paris, 4 July 2005
64#                                                            
65#                                               Bulletin C 30
66#                                 
67#                                               To authorities responsible 
68# 					      for the measurement and 
69# 					      distribution of time                                         
70# 
71# 
72#                                    UTC TIME STEP
73#                             on the 1st of January 2006
74#                       
75# 
76#  A positive leap second will be introduced at the end of December 2005.
77#  The sequence of dates of the UTC second markers will be:		
78# 		
79#                           2005 December 31,     23h 59m 59s
80#                           2005 December 31,     23h 59m 60s
81#                           2006 January   1,      0h  0m  0s
82#               
83#  The difference between UTC and the International Atomic Time TAI is:
84#   
85#   from 1999 January 1, 0h UTC, to 2006 January 1  0h UTC  : UTC-TAI = - 32s
86#   from 2006 January 1, 0h UTC, until further notice       : UTC-TAI = - 33s
87#   
88#  Leap seconds can be introduced in UTC at the end of the months of December 
89#  or June, depending on the evolution of UT1-TAI. Bulletin C is mailed every 
90#  six months, either to announce a time step in UTC or to confirm that there 
91#  will be no time step at the next possible date.
92#  
93# 
94# 
95#                                               Daniel GAMBIS
96#                                               Head		
97#                                               Earth Orientation Center of IERS
98# 					      Observatoire de Paris, France
99# 
100