[time-nuts] How many seconds in a year?

hasweb at has.org.nz hasweb at has.org.nz
Tue Oct 14 22:58:13 UTC 2008

Neville Michie wrote:
> Hi,
> the GPS system obviously counts seconds, and weeks.  When the solar   
> year develops a  phase
> difference of more than half a second the UTC crowd  consider a leap  
>  second, so what is the current
> rotational velocity of the Earth, either WRT the Sun or the stars?  
> In  seconds.
> I could find many answers on Google but none that seemed good enough  
>  to set your clock by.
> By clock I just mean a rubidium clock that is harmonised to the GPS  system.
> cheers, Neville Michie

Leapseconds are due to the fact that the Earths rotation period about  
its axis wrt the mean sun is not exactly 86400 seconds.
The rate isnt spot on and the rotation period evolves with time due to  
earthquakes and other causes.

The length of the year is another matter entirely.


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