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# NIST format leap-seconds.list file, which can be copied from 7# <ftp://ftp.nist.gov/pub/time/leap-seconds.list> 8# or <ftp://ftp.boulder.nist.gov/pub/time/leap-seconds.list>. 9# The NIST file is used instead of its IERS upstream counterpart 10# <https://hpiers.obspm.fr/iers/bul/bulc/ntp/leap-seconds.list> 11# because under US law the NIST file is public domain 12# whereas the IERS file's copyright and license status is unclear. 13# For more about leap-seconds.list, please see 14# The NTP Timescale and Leap Seconds 15# <https://www.eecis.udel.edu/~mills/leap.html>. 16 17# The rules for leap seconds are specified in Annex 1 (Time scales) of: 18# Standard-frequency and time-signal emissions. 19# International Telecommunication Union - Radiocommunication Sector 20# (ITU-R) Recommendation TF.460-6 (02/2002) 21# <https://www.itu.int/rec/R-REC-TF.460-6-200202-I/>. 22# The International Earth Rotation and Reference Systems Service (IERS) 23# periodically uses leap seconds to keep UTC to within 0.9 s of UT1 24# (a proxy for Earth's angle in space as measured by astronomers) 25# and publishes leap second data in a copyrighted file 26# <https://hpiers.obspm.fr/iers/bul/bulc/Leap_Second.dat>. 27# See: Levine J. Coordinated Universal Time and the leap second. 28# URSI Radio Sci Bull. 2016;89(4):30-6. doi:10.23919/URSIRSB.2016.7909995 29# <https://ieeexplore.ieee.org/document/7909995>. 30 31# There were no leap seconds before 1972, as no official mechanism 32# accounted for the discrepancy between atomic time (TAI) and the earth's 33# rotation. The first ("1 Jan 1972") data line in leap-seconds.list 34# does not denote a leap second; it denotes the start of the current definition 35# of UTC. 36 37# All leap-seconds are Stationary (S) at the given UTC time. 38# The correction (+ or -) is made at the given time, so in the unlikely 39# event of a negative leap second, a line would look like this: 40# Leap YEAR MON DAY 23:59:59 - S 41# Typical lines look like this: 42# Leap YEAR MON DAY 23:59:60 + S 43Leap 1972 Jun 30 23:59:60 + S 44Leap 1972 Dec 31 23:59:60 + S 45Leap 1973 Dec 31 23:59:60 + S 46Leap 1974 Dec 31 23:59:60 + S 47Leap 1975 Dec 31 23:59:60 + S 48Leap 1976 Dec 31 23:59:60 + S 49Leap 1977 Dec 31 23:59:60 + S 50Leap 1978 Dec 31 23:59:60 + S 51Leap 1979 Dec 31 23:59:60 + S 52Leap 1981 Jun 30 23:59:60 + S 53Leap 1982 Jun 30 23:59:60 + S 54Leap 1983 Jun 30 23:59:60 + S 55Leap 1985 Jun 30 23:59:60 + S 56Leap 1987 Dec 31 23:59:60 + S 57Leap 1989 Dec 31 23:59:60 + S 58Leap 1990 Dec 31 23:59:60 + S 59Leap 1992 Jun 30 23:59:60 + S 60Leap 1993 Jun 30 23:59:60 + S 61Leap 1994 Jun 30 23:59:60 + S 62Leap 1995 Dec 31 23:59:60 + S 63Leap 1997 Jun 30 23:59:60 + S 64Leap 1998 Dec 31 23:59:60 + S 65Leap 2005 Dec 31 23:59:60 + S 66Leap 2008 Dec 31 23:59:60 + S 67Leap 2012 Jun 30 23:59:60 + S 68Leap 2015 Jun 30 23:59:60 + S 69Leap 2016 Dec 31 23:59:60 + S 70 71# UTC timestamp when this leap second list expires. 72# Any additional leap seconds will come after this. 73# This Expires line is commented out for now, 74# so that pre-2020a zic implementations do not reject this file. 75#Expires 2022 Dec 28 00:00:00 76 77# POSIX timestamps for the data in this file: 78#updated 1467936000 (2016-07-08 00:00:00 UTC) 79#expires 1672185600 (2022-12-28 00:00:00 UTC) 80 81# Updated through IERS Bulletin C63 82# File expires on: 28 December 2022 83