[LEAPSECS] The definition of a day

Clive D.W. Feather clive at davros.org
Thu Jan 29 17:00:52 EST 2015

Peter Vince said:
>      Surely it would be better to allow "civil time" to run smoothly from
> atomic clocks, and give ourselves a few hundred years to quietly consider
> how to correct the slow drift that has reached the same order of magnitude
> as the analemma effect, which we regularly ignore and/or aren't even aware
> of?

There's already a proposal for solving this - one that I support. That is
to allow each polity to decide when the drift is large enough to be
annoying and then make a 1 hour change to their (local time - UTC) delta
value. For those polities that make a twice-yearly change anyway, this
could be done by omitting one such change.

So, let us suppose the year 2600 is when the drift reaches the annoying
point, and let us suppose the EU is still in existence. By then the sun will
reach its highest point at about 12:45 UTC. So at this point the EU
announces (a few years ahead) that the normal autumn shift back of the
clocks will not happen. From autumn 2600 onwards, the UK will observe
UTC+0100 in the winter and UTC+0200 in the summer; France will observe
UTC+0200 and +0300, and so on.

Dealing with local time changes as you cross borders is something people
are used to, as is the fact that the amount of change varies both within
the year and from year to year. So there's nothing new for people to get
used to.


Clive D.W. Feather          | If you lie to the compiler,
Email: clive at davros.org     | it will get its revenge.
Web: http://www.davros.org  |   - Henry Spencer
Mobile: +44 7973 377646

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