31a7e0032c
SERVICE INTERNATIONAL DE LA ROTATION TERRESTRE BUREAU CENTRAL DE L'IERS OBSERVATOIRE DE PARIS 61, Av. de l'Observatoire 75014 PARIS (France) Tel. : 33 (0) 1 40 51 22 26 FAX : 33 (0) 1 40 51 22 91 Internet : iers@obspm.fr Paris, 17 July 1998 Bulletin C 16 To authorities responsible for the measurement and distribution of time UTC TIME STEP on the 1st of January 1999 A positive leap second will be introduced at the end of December 1998. The sequence of dates of the UTC second markers will be: 1998 December 31, 23h 59m 59s 1998 December 31, 23h 59m 60s 1999 January 1, 0h 0m 0s The difference between UTC and the International Atomic Time TAI is: from 1997 July 1, 0h UTC, to 1999 January 1, 0h UTC : UTC-TAI = - 31s from 1999 January 1, 0h UTC, until further notice : UTC-TAI = - 32s 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 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 Central Bureau of IERS
45 lines
1.5 KiB
Plaintext
45 lines
1.5 KiB
Plaintext
# @(#)leapseconds 7.9
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# Allowance for leapseconds added to each timezone file.
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# The International Earth Rotation Service periodically uses leap seconds
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# to keep UTC to within 0.9 s of TAI (atomic time); see
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# Terry J Quinn, The BIPM and the accurate measure of time,
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# Proc IEEE 79, 7 (July 1991), 894-905.
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# There were no leap seconds before 1972, because the official mechanism
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# accounting for the discrepancy between atomic time and the earth's rotation
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# did not exist until the early 1970s.
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# The correction (+ or -) is made at the given time, so lines
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# will typically look like:
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# Leap YEAR MON DAY 23:59:60 + R/S
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# or
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# Leap YEAR MON DAY 23:59:59 - R/S
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# If the leapsecond is Rolling (R) the given time is local time
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# If the leapsecond is Stationary (S) the given time is GMT
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# Leap YEAR MONTH DAY HH:MM:SS CORR R/S
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Leap 1972 Jun 30 23:59:60 + S
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Leap 1972 Dec 31 23:59:60 + S
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Leap 1973 Dec 31 23:59:60 + S
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Leap 1974 Dec 31 23:59:60 + S
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Leap 1975 Dec 31 23:59:60 + S
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Leap 1976 Dec 31 23:59:60 + S
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Leap 1977 Dec 31 23:59:60 + S
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Leap 1978 Dec 31 23:59:60 + S
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Leap 1979 Dec 31 23:59:60 + S
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Leap 1981 Jun 30 23:59:60 + S
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Leap 1982 Jun 30 23:59:60 + S
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Leap 1983 Jun 30 23:59:60 + S
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Leap 1985 Jun 30 23:59:60 + S
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Leap 1987 Dec 31 23:59:60 + S
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Leap 1989 Dec 31 23:59:60 + S
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Leap 1990 Dec 31 23:59:60 + S
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Leap 1992 Jun 30 23:59:60 + S
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Leap 1993 Jun 30 23:59:60 + S
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Leap 1994 Jun 30 23:59:60 + S
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Leap 1995 Dec 31 23:59:60 + S
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Leap 1997 Jun 30 23:59:60 + S
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Lesp 1998 Dec 31 23:59:60 + S
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