http://www.codemonkey.org.uk/2008/12/31/leap-seconds/ Dave Jones' Linux & opensource stuff. Sun, 15 Nov 2009 23:10:55 +0000 http://wordpress.org/?v=2.9.1 hourly 1 http://www.codemonkey.org.uk/2008/12/31/leap-seconds/comment-page-1/#comment-32 Andy Wingo Sat, 03 Jan 2009 19:33:48 +0000 http://www.codemonkey.org.uk/?p=37#comment-32 Very neat explanation, and neat bug! Very neat explanation, and neat bug!

]]> http://www.codemonkey.org.uk/2008/12/31/leap-seconds/comment-page-1/#comment-10 More on leap seconds. | codemonkey.org.uk Thu, 01 Jan 2009 03:10:06 +0000 http://www.codemonkey.org.uk/?p=37#comment-10 [...] Keating made a comment in my previous post on leap seconds, which I thought was worth highlighting in another post, for the benefit of those who don’t [...] [...] Keating made a comment in my previous post on leap seconds, which I thought was worth highlighting in another post, for the benefit of those who don’t [...]

]]> http://www.codemonkey.org.uk/2008/12/31/leap-seconds/comment-page-1/#comment-9 jkeating Thu, 01 Jan 2009 02:51:56 +0000 http://www.codemonkey.org.uk/?p=37#comment-9 It could be <a href="http://zuneinsider.com/archive/2008/12/31/30gb-zune-issues-official-update.aspx" rel="nofollow">worse...</a> It could be worse…

]]> http://www.codemonkey.org.uk/2008/12/31/leap-seconds/comment-page-1/#comment-8 Leap Second : Bob Plankers, The Lone Sysadmin Wed, 31 Dec 2008 21:53:29 +0000 http://www.codemonkey.org.uk/?p=37#comment-8 [...] Dave Jones’ post reminded me that tonight we have a leap second. 23:59:59 will be followed by 23:59:60. Wikipedia saves me the trouble of explaining why: Leap seconds are necessary because time is measured using stable atomic clocks (TAI or International Atomic Time), whereas the rotation of Earth slows down continually, though at a slightly variable rate. Originally, the second was defined as 1/86400 of a mean solar day (see solar time) as determined by the rotation of the Earth around its axis. By the middle of the 20th century it was apparent that the rotation of the Earth did not provide a sufficiently uniform time standard and in 1956 the second was redefined in terms of the annual orbital revolution of the Earth around the Sun. In 1967 the second was redefined, once again, in terms of a physical property: the oscillations of an atom of Caesium-133, which were measurable by an atomic clock. But the solar day becomes 1.7 ms longer every century due mainly to tidal friction (2.3 ms/cy, reduced by 0.6 ms/cy due to glacial rebound). [...] [...] Dave Jones’ post reminded me that tonight we have a leap second. 23:59:59 will be followed by 23:59:60. Wikipedia saves me the trouble of explaining why: Leap seconds are necessary because time is measured using stable atomic clocks (TAI or International Atomic Time), whereas the rotation of Earth slows down continually, though at a slightly variable rate. Originally, the second was defined as 1/86400 of a mean solar day (see solar time) as determined by the rotation of the Earth around its axis. By the middle of the 20th century it was apparent that the rotation of the Earth did not provide a sufficiently uniform time standard and in 1956 the second was redefined in terms of the annual orbital revolution of the Earth around the Sun. In 1967 the second was redefined, once again, in terms of a physical property: the oscillations of an atom of Caesium-133, which were measurable by an atomic clock. But the solar day becomes 1.7 ms longer every century due mainly to tidal friction (2.3 ms/cy, reduced by 0.6 ms/cy due to glacial rebound). [...]

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