[LEAPSECS] Straw men

Clive D.W. Feather clive at davros.org
Tue Jan 10 14:59:41 EST 2012

Ian Batten said:

> You cannot set up a bijection between successive 1s timestamps of UTC and successive valid 1s timestamps of UK Civil Time, because the civil timestamps between 01:00:00 and 02:00:00 on the fourth Sunday in October each map to two distinct UTC timestamps, as they are repeated in the sequence of UK Civil timestamps. Therefore UK Civil time is not mean solar time.

(1) I'm not convinced that's correct, since there's an implied labelling of
whether any given timestamp is in "the period of summer time" or not.

Note that, in the Act, "the period of summer time" is defined using GMT at
both ends. So the last timestamp is 02:00:00, but that is implicitly
"summer time" since it's defined as being the last one because it is "one
o'clock, Greenwich mean time".

(2) Not last year. The fourth Sunday in October was the 23rd. BST ended on
the 30th.

It's an interesting argument, though. I might try it on some lawyers.

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

More information about the LEAPSECS mailing list