[tz] CCTF survey on Time and Frequency Metrology - Telecom

Steve Allen sla at ucolick.org
Fri Jan 29 17:46:19 UTC 2021

On Fri 2021-01-29T10:33:35-0700 Paul Gilmartin via tz hath writ:
> I'm changing my stance on Leap Seconds: yes, it's a means of
> keeping UTC synchronized with the earth's rotation.  But I
> see no need.  Fix UTC forever at TAI - 42(?) s and make desired
> adjustments in civil time.  At some future date when the drift
> accumulates to several minutes, change my timezone from MST7MDT
> to MST7:15MDT.  This can be coordinated with the Spring clock
> reset: every few centuries that can be +45 minutes instead of
> +60.

The problem that originally brought us leap seconds was that the legal
definition of a calendar day in most countries is one mean solar day,
which means actually measuring the rotation of the earth.
Representatives from countries with such laws could not approve the
use of radio broadcast time signals deviating from that definition.

Because UTC by that name has become the basis of legal time in most
places it will be necessary to get consensus to change the definition
of the calendar day.  At the ITU-R WRC in 2015 the same issue arose
when a number of countries objected to changing UTC in a way that
redefined the calendar day.

Steve Allen                    <sla at ucolick.org>              WGS-84 (GPS)
UCO/Lick Observatory--ISB 260  Natural Sciences II, Room 165  Lat  +36.99855
1156 High Street               Voice: +1 831 459 3046         Lng -122.06015
Santa Cruz, CA 95064           https://www.ucolick.org/~sla/  Hgt +250 m

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