[ntp:questions] Leap second functional question

Unruh unruh-spam at physics.ubc.ca
Fri Feb 22 01:26:01 UTC 2008

David Woolley <david at ex.djwhome.demon.co.uk.invalid> writes:

>> You are asking for the impossible!  Leap seconds keep time in synch with 

>That was the intention.  I was pointing out that you can only use "true" 
>time to represent historic civil times, you cannot calculate the "true" 
>time of a future civil time beyond the first candidate leap second.

>> the earth's rotation.  The rate of rotation is subject to small 
>> variations.  This is why leap seconds occur at irregular intervals and 
>> why it is possible to have a negative leap second, although I don't 
>> recall that we ever had one.
>Exactly, which is why the question casts doubt on the use of "true" 
>time, which was my intention.

Well, I suppose one could assume no leap seconds into the future. It is as
good as UTC which does exactly that, except it also assumes no leap seconds
into the past, where we know it is wrong. Getting it half right would seem
an advance.

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