xref: /dragonfly/share/zoneinfo/leapseconds (revision 0fe46dc6)
1# Allowance for leap seconds added to each time zone file.
2
3# This file is in the public domain.
4
5# This file is generated automatically from the data in the public-domain
6# leap-seconds.list file available from most NIST time servers.
7# If the URL <ftp://time.nist.gov/pub/leap-seconds.list> does not work,
8# you should be able to pick up leap-seconds.list from a secondary NIST server.
9# See <http://tf.nist.gov/tf-cgi/servers.cgi> for a list of secondary servers.
10# For more about leap-seconds.list, please see
11# The NTP Timescale and Leap Seconds
12# http://www.eecis.udel.edu/~mills/leap.html
13
14# The International Earth Rotation and Reference Systems Service
15# periodically uses leap seconds to keep UTC to within 0.9 s of UT1
16# (which measures the true angular orientation of the earth in space); see
17# Terry J Quinn, The BIPM and the accurate measure of time,
18# Proc IEEE 79, 7 (July 1991), 894-905 <http://dx.doi.org/10.1109/5.84965>.
19# There were no leap seconds before 1972, because the official mechanism
20# accounting for the discrepancy between atomic time and the earth's rotation
21# did not exist until the early 1970s.
22
23# The correction (+ or -) is made at the given time, so lines
24# will typically look like:
25#	Leap	YEAR	MON	DAY	23:59:60	+	R/S
26# or
27#	Leap	YEAR	MON	DAY	23:59:59	-	R/S
28
29# If the leapsecond is Rolling (R) the given time is local time.
30# If the leapsecond is Stationary (S) the given time is UTC.
31
32# Leap	YEAR	MONTH	DAY	HH:MM:SS	CORR	R/S
33Leap	1972	Jun	30	23:59:60	+	S
34Leap	1972	Dec	31	23:59:60	+	S
35Leap	1973	Dec	31	23:59:60	+	S
36Leap	1974	Dec	31	23:59:60	+	S
37Leap	1975	Dec	31	23:59:60	+	S
38Leap	1976	Dec	31	23:59:60	+	S
39Leap	1977	Dec	31	23:59:60	+	S
40Leap	1978	Dec	31	23:59:60	+	S
41Leap	1979	Dec	31	23:59:60	+	S
42Leap	1981	Jun	30	23:59:60	+	S
43Leap	1982	Jun	30	23:59:60	+	S
44Leap	1983	Jun	30	23:59:60	+	S
45Leap	1985	Jun	30	23:59:60	+	S
46Leap	1987	Dec	31	23:59:60	+	S
47Leap	1989	Dec	31	23:59:60	+	S
48Leap	1990	Dec	31	23:59:60	+	S
49Leap	1992	Jun	30	23:59:60	+	S
50Leap	1993	Jun	30	23:59:60	+	S
51Leap	1994	Jun	30	23:59:60	+	S
52Leap	1995	Dec	31	23:59:60	+	S
53Leap	1997	Jun	30	23:59:60	+	S
54Leap	1998	Dec	31	23:59:60	+	S
55Leap	2005	Dec	31	23:59:60	+	S
56Leap	2008	Dec	31	23:59:60	+	S
57Leap	2012	Jun	30	23:59:60	+	S
58Leap	2015	Jun	30	23:59:60	+	S
59Leap	2016	Dec	31	23:59:60	+	S
60
61#	Updated through IERS Bulletin C52
62#	File expires on:  28 June 2017
63