# Allowance for leap seconds added to each time zone file. # This file is in the public domain. # This file is generated automatically from the data in the public-domain # NIST/IERS format leap-seconds.list file, which can be copied from # <https://hpiers.obspm.fr/iers/bul/bulc/ntp/leap-seconds.list> # or, in a variant with different comments, from # <ftp://ftp.boulder.nist.gov/pub/time/leap-seconds.list>. # For more about leap-seconds.list, please see # The NTP Timescale and Leap Seconds # <https://www.eecis.udel.edu/~mills/leap.html>. # The rules for leap seconds are specified in Annex 1 (Time scales) of: # Standard-frequency and time-signal emissions. # International Telecommunication Union - Radiocommunication Sector # (ITU-R) Recommendation TF.460-6 (02/2002) # <https://www.itu.int/rec/R-REC-TF.460-6-200202-I/>. # The International Earth Rotation and Reference Systems Service (IERS) # periodically uses leap seconds to keep UTC to within 0.9 s of UT1 # (a proxy for Earth's angle in space as measured by astronomers) # and publishes leap second data in a copyrighted file # <https://hpiers.obspm.fr/iers/bul/bulc/Leap_Second.dat>. # See: Levine J. Coordinated Universal Time and the leap second. # URSI Radio Sci Bull. 2016;89(4):30-6. doi:10.23919/URSIRSB.2016.7909995 # <https://ieeexplore.ieee.org/document/7909995>. # There were no leap seconds before 1972, as no official mechanism # accounted for the discrepancy between atomic time (TAI) and the earth's # rotation. The first ("1 Jan 1972") data line in leap-seconds.list # does not denote a leap second; it denotes the start of the current definition # of UTC. # All leap-seconds are Stationary (S) at the given UTC time. # The correction (+ or -) is made at the given time, so in the unlikely # event of a negative leap second, a line would look like this: # Leap YEAR MON DAY 23:59:59 - S # Typical lines look like this: # Leap YEAR MON DAY 23:59:60 + S Leap 1972 Jun 30 23:59:60 + S Leap 1972 Dec 31 23:59:60 + S Leap 1973 Dec 31 23:59:60 + S Leap 1974 Dec 31 23:59:60 + S Leap 1975 Dec 31 23:59:60 + S Leap 1976 Dec 31 23:59:60 + S Leap 1977 Dec 31 23:59:60 + S Leap 1978 Dec 31 23:59:60 + S Leap 1979 Dec 31 23:59:60 + S Leap 1981 Jun 30 23:59:60 + S Leap 1982 Jun 30 23:59:60 + S Leap 1983 Jun 30 23:59:60 + S Leap 1985 Jun 30 23:59:60 + S Leap 1987 Dec 31 23:59:60 + S Leap 1989 Dec 31 23:59:60 + S Leap 1990 Dec 31 23:59:60 + S Leap 1992 Jun 30 23:59:60 + S Leap 1993 Jun 30 23:59:60 + S Leap 1994 Jun 30 23:59:60 + S Leap 1995 Dec 31 23:59:60 + S Leap 1997 Jun 30 23:59:60 + S Leap 1998 Dec 31 23:59:60 + S Leap 2005 Dec 31 23:59:60 + S Leap 2008 Dec 31 23:59:60 + S Leap 2012 Jun 30 23:59:60 + S Leap 2015 Jun 30 23:59:60 + S Leap 2016 Dec 31 23:59:60 + S # UTC timestamp when this leap second list expires. # Any additional leap seconds will come after this. # This Expires line is commented out for now, # so that pre-2020a zic implementations do not reject this file. #Expires 2025 Dec 28 00:00:00 # POSIX timestamps for the data in this file: #updated 1736208000 (2025-01-07 00:00:00 UTC) #expires 1766880000 (2025-12-28 00:00:00 UTC) # Updated through IERS Bulletin C (https://hpiers.obspm.fr/iers/bul/bulc/bulletinc.dat) # File expires on 28 December 2025