leapseconds revision 1.4.2.1
1 1.2 kre # Allowance for leap seconds added to each time zone file. 2 1.1 apb 3 1.1 apb # This file is in the public domain. 4 1.1 apb 5 1.1 apb # This file is generated automatically from the data in the public-domain 6 1.2 kre # NIST format leap-seconds.list file, which can be copied from 7 1.2 kre # <ftp://ftp.nist.gov/pub/time/leap-seconds.list> 8 1.2 kre # or <ftp://ftp.boulder.nist.gov/pub/time/leap-seconds.list>. 9 1.2 kre # The NIST file is used instead of its IERS upstream counterpart 10 1.2 kre # <https://hpiers.obspm.fr/iers/bul/bulc/ntp/leap-seconds.list> 11 1.2 kre # because under US law the NIST file is public domain 12 1.2 kre # whereas the IERS file's copyright and license status is unclear. 13 1.1 apb # For more about leap-seconds.list, please see 14 1.1 apb # The NTP Timescale and Leap Seconds 15 1.2 kre # <https://www.eecis.udel.edu/~mills/leap.html>. 16 1.1 apb 17 1.2 kre # The rules for leap seconds are specified in Annex 1 (Time scales) of: 18 1.2 kre # Standard-frequency and time-signal emissions. 19 1.2 kre # International Telecommunication Union - Radiocommunication Sector 20 1.2 kre # (ITU-R) Recommendation TF.460-6 (02/2002) 21 1.2 kre # <https://www.itu.int/rec/R-REC-TF.460-6-200202-I/>. 22 1.2 kre # The International Earth Rotation and Reference Systems Service (IERS) 23 1.2 kre # periodically uses leap seconds to keep UTC to within 0.9 s of UT1 24 1.2 kre # (a proxy for Earth's angle in space as measured by astronomers) 25 1.2 kre # and publishes leap second data in a copyrighted file 26 1.2 kre # <https://hpiers.obspm.fr/iers/bul/bulc/Leap_Second.dat>. 27 1.2 kre # See: Levine J. Coordinated Universal Time and the leap second. 28 1.2 kre # URSI Radio Sci Bull. 2016;89(4):30-6. doi:10.23919/URSIRSB.2016.7909995 29 1.2 kre # <https://ieeexplore.ieee.org/document/7909995>. 30 1.2 kre 31 1.2 kre # There were no leap seconds before 1972, as no official mechanism 32 1.2 kre # accounted for the discrepancy between atomic time (TAI) and the earth's 33 1.2 kre # rotation. The first ("1 Jan 1972") data line in leap-seconds.list 34 1.2 kre # does not denote a leap second; it denotes the start of the current definition 35 1.2 kre # of UTC. 36 1.2 kre 37 1.2 kre # All leap-seconds are Stationary (S) at the given UTC time. 38 1.2 kre # The correction (+ or -) is made at the given time, so in the unlikely 39 1.2 kre # event of a negative leap second, a line would look like this: 40 1.2 kre # Leap YEAR MON DAY 23:59:59 - S 41 1.2 kre # Typical lines look like this: 42 1.2 kre # Leap YEAR MON DAY 23:59:60 + S 43 1.1 apb Leap 1972 Jun 30 23:59:60 + S 44 1.1 apb Leap 1972 Dec 31 23:59:60 + S 45 1.1 apb Leap 1973 Dec 31 23:59:60 + S 46 1.1 apb Leap 1974 Dec 31 23:59:60 + S 47 1.1 apb Leap 1975 Dec 31 23:59:60 + S 48 1.1 apb Leap 1976 Dec 31 23:59:60 + S 49 1.1 apb Leap 1977 Dec 31 23:59:60 + S 50 1.1 apb Leap 1978 Dec 31 23:59:60 + S 51 1.1 apb Leap 1979 Dec 31 23:59:60 + S 52 1.1 apb Leap 1981 Jun 30 23:59:60 + S 53 1.1 apb Leap 1982 Jun 30 23:59:60 + S 54 1.1 apb Leap 1983 Jun 30 23:59:60 + S 55 1.1 apb Leap 1985 Jun 30 23:59:60 + S 56 1.1 apb Leap 1987 Dec 31 23:59:60 + S 57 1.1 apb Leap 1989 Dec 31 23:59:60 + S 58 1.1 apb Leap 1990 Dec 31 23:59:60 + S 59 1.1 apb Leap 1992 Jun 30 23:59:60 + S 60 1.1 apb Leap 1993 Jun 30 23:59:60 + S 61 1.1 apb Leap 1994 Jun 30 23:59:60 + S 62 1.1 apb Leap 1995 Dec 31 23:59:60 + S 63 1.1 apb Leap 1997 Jun 30 23:59:60 + S 64 1.1 apb Leap 1998 Dec 31 23:59:60 + S 65 1.1 apb Leap 2005 Dec 31 23:59:60 + S 66 1.1 apb Leap 2008 Dec 31 23:59:60 + S 67 1.1 apb Leap 2012 Jun 30 23:59:60 + S 68 1.2 kre Leap 2015 Jun 30 23:59:60 + S 69 1.2 kre Leap 2016 Dec 31 23:59:60 + S 70 1.2 kre 71 1.2 kre # UTC timestamp when this leap second list expires. 72 1.2 kre # Any additional leap seconds will come after this. 73 1.2 kre # This Expires line is commented out for now, 74 1.2 kre # so that pre-2020a zic implementations do not reject this file. 75 1.4.2.1 martin #Expires 2023 Dec 28 00:00:00 76 1.2 kre 77 1.2 kre # POSIX timestamps for the data in this file: 78 1.2 kre #updated 1467936000 (2016-07-08 00:00:00 UTC) 79 1.4.2.1 martin #expires 1703721600 (2023-12-28 00:00:00 UTC) 80 1.2 kre 81 1.4.2.1 martin # Updated through IERS Bulletin C65 82 1.4.2.1 martin # File expires on: 28 December 2023 83
Indexes created Tue Aug 18 00:25:06 UTC 2026