[LEAPSECS] New time scale name

Tony Finch dot at dotat.at
Thu Aug 12 19:58:02 EDT 2010

On 12 Aug 2010, at 21:25, Michael Deckers <michael.deckers at yahoo.com> wrote:


> I fear that the matter is less simple. The proposal keeps the

> name UTC for the newly defined timescale. (And unfortunately,

> there is precedent with essential changes in definitions of well

> established time scales: GMT.)

AIUI the UT* terms disambiguate the various meanings of GMT (ish). Perhaps the name UTC will be superseded in a similar way, becoming ambiguous and replaced by new terms.

> So that, absurdly, those people

> who continue to use UTC in the established sense could not keep

> the well-established name for it -- they would have to find a

> new name to avoid ambiguity (eg, UTL for UT with leap seconds).

UTC cannot exist without a recognised authority who determines when leap seconds occur. If that authority stops adding leap seconds and breaks the |DUT1| < 0.9s guarantee I doubt anyone will take over the job. It would probably be easier to switch over to using the GPS time scale and ephemeris.

GMT was also tied to a particular maintenance regime and stopped being a precise timescale when it was no longer being maintained.

f.anthony.n.finch <dot at dotat.at> http://dotat.at/

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