On 01/07/2011 07:55, Rob Seaman wrote:
Eliminating leap seconds is an attempt to change the period of the day.  But 
the Sun says otherwise.

No. Eliminating leap seconds keeps the period of the day constant. It is always 86400 SI seconds long, by definition. On LEAP DAY, the day is 86401 SI seconds long. Eliminating leap seconds eliminates the rough synchronization between mean solar time and UTC labeling of seconds. You aren't changing the length of the day, but rather changing the synchronization to the sun based on the wobble in the rock we live on.

BTW, It does this by adding a second that's labeled in weird way making UTC a non-uniform radix system. That non-uniformity is poorly implemented, and often ignored because "it's only a second, why should that matter" attitude makes it nearly impossible to implement correctly for those situations that do care. The infrequent nature of leap seconds also means that they are prone to regression and nobody will notice for years. I fixed a bug in FreeBSD years ago where the leap second would occur at effectively a random time of day because the underlying time keeping system was changed in a way to make it more efficient. Only this detail was wrong. That change was in 1998, and I fixed the bug in 2003 when I was doing leap second testing/conformance. The bug was introduced by somebody who should have known better too, not just some random kernel hacker making a random change to suit them.

Warner
_______________________________________________
LEAPSECS mailing list
[email protected]
http://six.pairlist.net/mailman/listinfo/leapsecs

Reply via email to