diff options
Diffstat (limited to 'leap-seconds.list')
| -rw-r--r-- | leap-seconds.list | 30 |
1 files changed, 15 insertions, 15 deletions
diff --git a/leap-seconds.list b/leap-seconds.list index e52effc257b2..da0efc8c8566 100644 --- a/leap-seconds.list +++ b/leap-seconds.list @@ -1,5 +1,5 @@ -# ATOMIC TIME. -# The Coordinated Universal Time (UTC) is the reference time scale derived +# ATOMIC TIME +# Coordinated Universal Time (UTC) is the reference time scale derived # from The "Temps Atomique International" (TAI) calculated by the Bureau # International des Poids et Mesures (BIPM) using a worldwide network of atomic # clocks. UTC differs from TAI by an integer number of seconds; it is the basis @@ -8,34 +8,34 @@ # # ASTRONOMICAL TIME (UT1) is the time scale based on the rate of rotation of the earth. # It is now mainly derived from Very Long Baseline Interferometry (VLBI). The various -# irregular fluctuations progressively detected in the rotation rate of the Earth lead +# irregular fluctuations progressively detected in the rotation rate of the Earth led # in 1972 to the replacement of UT1 by UTC as the reference time scale. # # # LEAP SECOND -# Atomic clocks are more stable than the rate of the earth rotation since the latter +# Atomic clocks are more stable than the rate of the earth's rotation since the latter # undergoes a full range of geophysical perturbations at various time scales: lunisolar -# and core-mantle torques, atmospheric and oceanic effetcs, etc. +# and core-mantle torques, atmospheric and oceanic effects, etc. # Leap seconds are needed to keep the two time scales in agreement, i.e. UT1-UTC smaller -# than 0.9 second. Therefore, when necessary a "leap second" is applied to UTC. +# than 0.9 seconds. Therefore, when necessary a "leap second" is applied to UTC. # Since the adoption of this system in 1972 it has been necessary to add a number of seconds to UTC, # firstly due to the initial choice of the value of the second (1/86400 mean solar day of # the year 1820) and secondly to the general slowing down of the Earth's rotation. It is -# theorically possible to have a negative leap second (a second removed from UTC), but so far, +# theoretically possible to have a negative leap second (a second removed from UTC), but so far, # all leap seconds have been positive (a second has been added to UTC). Based on what we know about # the earth's rotation, it is unlikely that we will ever have a negative leap second. # # # HISTORY -# The first leap second was added on June 30, 1972. Until yhe year 2000, it was necessary in average to add a +# The first leap second was added on June 30, 1972. Until the year 2000, it was necessary in average to add a # leap second at a rate of 1 to 2 years. Since the year 2000 leap seconds are introduced with an -# average interval of 3 to 4 years due to the acceleration of the Earth rotation speed. +# average interval of 3 to 4 years due to the acceleration of the Earth's rotation speed. # # -# RESPONSABILITY OF THE DECISION TO INTRODUCE A LEAP SECOND IN UTC +# RESPONSIBILITY OF THE DECISION TO INTRODUCE A LEAP SECOND IN UTC # The decision to introduce a leap second in UTC is the responsibility of the Earth Orientation Center of # the International Earth Rotation and reference System Service (IERS). This center is located at Paris -# Observatory. According to international agreements, leap seconds should only be scheduled for certain dates: +# Observatory. According to international agreements, leap seconds should be scheduled only for certain dates: # first preference is given to the end of December and June, and second preference at the end of March # and September. Since the introduction of leap seconds in 1972, only dates in June and December were used. # @@ -60,15 +60,15 @@ # # The following line shows the last update of this file in NTP timestamp: # -#$ 3913697179 +#$ 3929093563 # # 2) Expiration date of the file given on a semi-annual basis: last June or last December # -# File expires on 28 December 2024 +# File expires on 28 June 2025 # # Expire date in NTP timestamp: # -#@ 3944332800 +#@ 3960057600 # # # LIST OF LEAP SECONDS @@ -117,4 +117,4 @@ # please see the readme file in the 'source' directory : # https://hpiers.obspm.fr/iers/bul/bulc/ntp/sources/README # -#h 9dac5845 8acd32c0 2947d462 daf4a943 f58d9391 +#h be738595 57b0cf1b b0218343 fb77062f 5a775e7 |