[LEAPSECS] How good could civil timekeeping be?

Paul J. Ste. Marie paul_j at ste-marie.org
Sun Feb 17 02:45:26 EST 2008

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


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