minix/commands/zoneinfo/leapseconds
Ben Gras 3b2c65e323 Import of original zoneinfo code and database - tzcode
old-tzcode-32-bit-output and tzdata2007d.
2007-03-26 10:55:16 +00:00

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2.9 KiB
Text

# @(#)leapseconds 8.3
# Allowance for leapseconds added to each timezone file.
# The International Earth Rotation Service periodically uses leap seconds
# to keep UTC to within 0.9 s of UT1
# (which measures the true angular orientation of the earth in space); see
# Terry J Quinn, The BIPM and the accurate measure of time,
# Proc IEEE 79, 7 (July 1991), 894-905.
# There were no leap seconds before 1972, because the official mechanism
# accounting for the discrepancy between atomic time and the earth's rotation
# did not exist until the early 1970s.
# The correction (+ or -) is made at the given time, so lines
# will typically look like:
# Leap YEAR MON DAY 23:59:60 + R/S
# or
# Leap YEAR MON DAY 23:59:59 - R/S
# If the leapsecond is Rolling (R) the given time is local time
# If the leapsecond is Stationary (S) the given time is UTC
# Leap YEAR MONTH DAY HH:MM:SS CORR R/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
# ...
# Sent: Thursday, February 01, 2007 9:49 AM
# ...
# Subject: Bulletin C number 33
#
# INTERNATIONAL EARTH ROTATION AND REFERENCE SYSTEMS SERVICE (IERS)
#
# SERVICE INTERNATIONAL DE LA ROTATION TERRESTRE ET DES SYSTEMES DE REFERENCE
#
# SERVICE DE LA ROTATION TERRESTRE
# OBSERVATOIRE DE PARIS
# 61, Av. de l'Observatoire 75014 PARIS (France)
# ...
#
# Paris, 1 February 2007
# Bulletin C 33
# To authorities responsible
# for the measurement and
# distribution of time
#
# INFORMATION ON UTC - TAI
#
# NO positive leap second will be introduced at the end of June 2007.
# The difference between Coordinated Universal Time UTC and the
# International Atomic Time TAI is:
# from 2006 January 1, 0h UTC, until further notice : UTC-TAI = -33 s
# Leap seconds can be introduced in UTC at the end of the months of
# December or June, depending on the evolution of UT1-TAI. Bulletin C is
# mailed every six months, either to announce a time step in UTC, or to
# confirm that there will be no time step at the next possible date.
#
# Daniel GAMBIS
# Director
# Earth Orientation Center of IERS
# Observatoire de Paris, France