zic.tproj/datfiles/leapseconds

   1 # @(#)leapseconds       7.13
   2
   3 # $FreeBSD: src/share/zoneinfo/leapseconds,v 1.6 2001/04/06 16:46:52 wollman Exp $
   4
   5 # Allowance for leapseconds added to each timezone file.
   6
   7 # The International Earth Rotation Service periodically uses leap seconds
   8 # to keep UTC to within 0.9 s of UT1
   9 # (which measures the true angular orientation of the earth in space); see
  10 # Terry J Quinn, The BIPM and the accurate measure of time,
  11 # Proc IEEE 79, 7 (July 1991), 894-905.
  12 # There were no leap seconds before 1972, because the official mechanism
  13 # accounting for the discrepancy between atomic time and the earth's rotation
  14 # did not exist until the early 1970s.
  15
  16 # The correction (+ or -) is made at the given time, so lines
  17 # will typically look like:
  18 #       Leap    YEAR    MON     DAY     23:59:60        +       R/S
  19 # or
  20 #       Leap    YEAR    MON     DAY     23:59:59        -       R/S
  21
  22 # If the leapsecond is Rolling (R) the given time is local time
  23 # If the leapsecond is Stationary (S) the given time is UTC
  24
  25 # Leap  YEAR    MONTH   DAY     HH:MM:SS        CORR    R/S
  26 Leap    1972    Jun     30      23:59:60        +       S
  27 Leap    1972    Dec     31      23:59:60        +       S
  28 Leap    1973    Dec     31      23:59:60        +       S
  29 Leap    1974    Dec     31      23:59:60        +       S
  30 Leap    1975    Dec     31      23:59:60        +       S
  31 Leap    1976    Dec     31      23:59:60        +       S
  32 Leap    1977    Dec     31      23:59:60        +       S
  33 Leap    1978    Dec     31      23:59:60        +       S
  34 Leap    1979    Dec     31      23:59:60        +       S
  35 Leap    1981    Jun     30      23:59:60        +       S
  36 Leap    1982    Jun     30      23:59:60        +       S
  37 Leap    1983    Jun     30      23:59:60        +       S
  38 Leap    1985    Jun     30      23:59:60        +       S
  39 Leap    1987    Dec     31      23:59:60        +       S
  40 Leap    1989    Dec     31      23:59:60        +       S
  41 Leap    1990    Dec     31      23:59:60        +       S
  42 Leap    1992    Jun     30      23:59:60        +       S
  43 Leap    1993    Jun     30      23:59:60        +       S
  44 Leap    1994    Jun     30      23:59:60        +       S
  45 Leap    1995    Dec     31      23:59:60        +       S
  46 Leap    1997    Jun     30      23:59:60        +       S
  47 Leap    1998    Dec     31      23:59:60        +       S
  48 # INTERNATIONAL EARTH ROTATION SERVICE (IERS)
  49 # SERVICE INTERNATIONAL DE LA ROTATION TERRESTRE
  50 #
  51 # SERVICE DE LA ROTATION TERRESTRE
  52 # OBSERVATOIRE DE PARIS
  53 # 61, Av. de l'Observatoire 75014 PARIS (France)
  54 # Tel.      : 33 (0) 1 40 51 22 26
  55 # FAX       : 33 (0) 1 40 51 22 91
  56 # Internet  : iers@obspm.fr
  57 #
  58 # Paris, 11 January 2001
  59 #
  60 # Bulletin C 21
  61 #
  62 # To authorities responsible for the measurement and distribution of time
  63 #
  64 # INFORMATION ON UTC - TAI
  65 #
  66 # NO positive leap second will be introduced at the end of June 2001.