[LEAPSECS] How good could civil timekeeping be?

[Paul J. Ste. Marie]

On 2/15/2008 9:11 PM,  Rob Seaman allegedly wrote:


> 1a) Systems may need a table of leap seconds (after all, that's what  

> all the kvetching has been about).  Will this be required  

> indefinitely?  Maintenance procedures and such?


IBM mainframes have done this for at least 10-20 years.  Their TOD 
clocks are based on the original Unix definition, not the POSIX nonsense.



> 6) Airplanes navigate the skies.  Software systems to do this surely  

> both predate and postdate GPS.  The internal models to realize this  

> likely diverge in their interpretation of UTC.


The ATC system ran (runs?  did the FAA ever get their act together?) on 
IBM mainframes.  See above.  Navigation systems are more varying--the 
one I've seen details of used three independent implementations on 
disparate hardware platforms and a voting mechanism to resolve 
differences.



-- 
         --Paul