[LEAPSECS] Lets get REAL about time.

Steve Allen sla at ucolick.org
Fri Jan 20 13:35:56 EST 2012

On Fri 2012-01-20T16:34:12 +0000, Poul-Henning Kamp hath writ:

> PTP already uses TAI

Caution. PTP specifies TAI seconds, but uses the LORAN-C epoch
that is offset by the 10 (elastic) seconds.

Note that this caution contains elements which bear resemblance to the
(more recent, not from 10 years ago) position of the BIPM and CCTF.

Nothing can tick TAI seconds, for TAI is not known until next month,
so at the nanosecond level that assumption must be false.

The differences in epoch require very broad reiteration and
precautions lest someone mis-code the offset.

> TAI can be derived from UTC, GPS and other broadcast timescales, so

> availability is fine.

Indications have been that BIPM will disagree violently with that

Steve Allen <sla at ucolick.org> WGS-84 (GPS)
UCO/Lick Observatory--ISB Natural Sciences II, Room 165 Lat +36.99855
1156 High Street Voice: +1 831 459 3046 Lng -122.06015
Santa Cruz, CA 95064 http://www.ucolick.org/~sla/ Hgt +250 m

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