| leap-seconds.list (270817) | leap-seconds.list (279707) |
|---|---|
| 1# 2# In the following text, the symbol '#' introduces 3# a comment, which continues from that symbol until 4# the end of the line. A plain comment line has a 5# whitespace character following the comment indicator. 6# There are also special comment lines defined below. 7# A special comment will always have a non-whitespace 8# character in column 2. --- 33 unchanged lines hidden (view full) --- 42# laboratories and timing centers. Each laboratory 43# identifies its realization with its name: Thus 44# UTC(NIST), UTC(USNO), etc. The differences among 45# these different realizations are typically on the 46# order of a few nanoseconds (i.e., 0.000 000 00x s) 47# and can be ignored for many purposes. These differences 48# are tabulated in Circular T, which is published monthly 49# by the International Bureau of Weights and Measures | 1# 2# In the following text, the symbol '#' introduces 3# a comment, which continues from that symbol until 4# the end of the line. A plain comment line has a 5# whitespace character following the comment indicator. 6# There are also special comment lines defined below. 7# A special comment will always have a non-whitespace 8# character in column 2. --- 33 unchanged lines hidden (view full) --- 42# laboratories and timing centers. Each laboratory 43# identifies its realization with its name: Thus 44# UTC(NIST), UTC(USNO), etc. The differences among 45# these different realizations are typically on the 46# order of a few nanoseconds (i.e., 0.000 000 00x s) 47# and can be ignored for many purposes. These differences 48# are tabulated in Circular T, which is published monthly 49# by the International Bureau of Weights and Measures |
| 50# (BIPM). See www.bipm.fr for more information. | 50# (BIPM). See www.bipm.org for more information. |
| 51# 52# 3. The current definition of the relationship between UTC 53# and TAI dates from 1 January 1972. A number of different 54# time scales were in use before that epoch, and it can be 55# quite difficult to compute precise timestamps and time 56# intervals in those "prehistoric" days. For more information, 57# consult: 58# --- 63 unchanged lines hidden (view full) --- 122# 123# This complexity would not be needed for negative leap seconds (if they 124# are ever used). The UTC time would skip 23:59:59 and advance from 125# 23:59:58 to 00:00:00 in that case. The TAI offset would decrease by 126# 1 second at the same instant. This is a much easier situation to deal 127# with, since the difficulty of unambiguously representing the epoch 128# during the leap second does not arise. 129# | 51# 52# 3. The current definition of the relationship between UTC 53# and TAI dates from 1 January 1972. A number of different 54# time scales were in use before that epoch, and it can be 55# quite difficult to compute precise timestamps and time 56# intervals in those "prehistoric" days. For more information, 57# consult: 58# --- 63 unchanged lines hidden (view full) --- 122# 123# This complexity would not be needed for negative leap seconds (if they 124# are ever used). The UTC time would skip 23:59:59 and advance from 125# 23:59:58 to 00:00:00 in that case. The TAI offset would decrease by 126# 1 second at the same instant. This is a much easier situation to deal 127# with, since the difficulty of unambiguously representing the epoch 128# during the leap second does not arise. 129# |
| 130# Some systems implement leap seconds by amortizing the leap second 131# over the last few minutes of the day. The frequency of the local 132# clock is decreased (or increased) to realize the positive (or 133# negative) leap second. This method removes the time step described 134# above. Although the long-term behavior of the time scale is correct 135# in this case, this method introduces an error during the adjustment 136# period both in time and in frequency with respect to the official 137# defintion of UTC. 138# |
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| 130# Questions or comments to: 131# Judah Levine 132# Time and Frequency Division 133# NIST 134# Boulder, Colorado 135# Judah.Levine@nist.gov 136# | 139# Questions or comments to: 140# Judah Levine 141# Time and Frequency Division 142# NIST 143# Boulder, Colorado 144# Judah.Levine@nist.gov 145# |
| 137# Last Update of leap second values: 11 January 2012 | 146# Last Update of leap second values: 5 January 2015 |
| 138# 139# The following line shows this last update date in NTP timestamp 140# format. This is the date on which the most recent change to 141# the leap second data was added to the file. This line can 142# be identified by the unique pair of characters in the first two 143# columns as shown below. 144# | 147# 148# The following line shows this last update date in NTP timestamp 149# format. This is the date on which the most recent change to 150# the leap second data was added to the file. This line can 151# be identified by the unique pair of characters in the first two 152# columns as shown below. 153# |
| 145#$ 3535228800 | 154#$ 3629404800 |
| 146# 147# The NTP timestamps are in units of seconds since the NTP epoch, 148# which is 1 January 1900, 00:00:00. The Modified Julian Day number 149# corresponding to the NTP time stamp, X, can be computed as 150# 151# X/86400 + 15020 152# 153# where the first term converts seconds to days and the second --- 31 unchanged lines hidden (view full) --- 185# announced or at least one month before the effective date 186# (whichever is later). 187# If an announcement by the IERS specifies that no leap second is 188# scheduled, then only the expiration date of the file will 189# be advanced to show that the information in the file is still 190# current -- the update time stamp, the data and the name of the file 191# will not change. 192# | 155# 156# The NTP timestamps are in units of seconds since the NTP epoch, 157# which is 1 January 1900, 00:00:00. The Modified Julian Day number 158# corresponding to the NTP time stamp, X, can be computed as 159# 160# X/86400 + 15020 161# 162# where the first term converts seconds to days and the second --- 31 unchanged lines hidden (view full) --- 194# announced or at least one month before the effective date 195# (whichever is later). 196# If an announcement by the IERS specifies that no leap second is 197# scheduled, then only the expiration date of the file will 198# be advanced to show that the information in the file is still 199# current -- the update time stamp, the data and the name of the file 200# will not change. 201# |
| 193# Updated through IERS Bulletin C48 194# File expires on: 28 June 2015 | 202# Updated through IERS Bulletin C49 203# File expires on: 28 December 2015 |
| 195# | 204# |
| 196#@ 3644438400 | 205#@ 3660249600 |
| 197# 1982272060800 10 # 1 Jan 1972 1992287785600 11 # 1 Jul 1972 2002303683200 12 # 1 Jan 1973 2012335219200 13 # 1 Jan 1974 2022366755200 14 # 1 Jan 1975 2032398291200 15 # 1 Jan 1976 2042429913600 16 # 1 Jan 1977 --- 11 unchanged lines hidden (view full) --- 2162950473600 28 # 1 Jul 1993 2172982009600 29 # 1 Jul 1994 2183029443200 30 # 1 Jan 1996 2193076704000 31 # 1 Jul 1997 2203124137600 32 # 1 Jan 1999 2213345062400 33 # 1 Jan 2006 2223439756800 34 # 1 Jan 2009 2233550089600 35 # 1 Jul 2012 | 206# 2072272060800 10 # 1 Jan 1972 2082287785600 11 # 1 Jul 1972 2092303683200 12 # 1 Jan 1973 2102335219200 13 # 1 Jan 1974 2112366755200 14 # 1 Jan 1975 2122398291200 15 # 1 Jan 1976 2132429913600 16 # 1 Jan 1977 --- 11 unchanged lines hidden (view full) --- 2252950473600 28 # 1 Jul 1993 2262982009600 29 # 1 Jul 1994 2273029443200 30 # 1 Jan 1996 2283076704000 31 # 1 Jul 1997 2293124137600 32 # 1 Jan 1999 2303345062400 33 # 1 Jan 2006 2313439756800 34 # 1 Jan 2009 2323550089600 35 # 1 Jul 2012 |
| 2333644697600 36 # 1 Jul 2015 |
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| 224# 225# the following special comment contains the 226# hash value of the data in this file computed 227# use the secure hash algorithm as specified 228# by FIPS 180-1. See the files in ~/pub/sha for 229# the details of how this hash value is 230# computed. Note that the hash computation 231# ignores comments and whitespace characters 232# in data lines. It includes the NTP values 233# of both the last modification time and the 234# expiration time of the file, but not the 235# white space on those lines. 236# the hash line is also ignored in the 237# computation. 238# | 234# 235# the following special comment contains the 236# hash value of the data in this file computed 237# use the secure hash algorithm as specified 238# by FIPS 180-1. See the files in ~/pub/sha for 239# the details of how this hash value is 240# computed. Note that the hash computation 241# ignores comments and whitespace characters 242# in data lines. It includes the NTP values 243# of both the last modification time and the 244# expiration time of the file, but not the 245# white space on those lines. 246# the hash line is also ignored in the 247# computation. 248# |
| 239#h a4862ccd c6f43c6 964f3604 85944a26 b5cfad4e | 249#h 45e70fa7 a9df2033 f4a49ab0 ec648273 7b6c22c |