[LEAPSECS] BBC radio Crowd Science

[John Sauter]

On Sun, 2017-01-29 at 15:33 +0000, Michael.Deckers. via LEAPSECS wrote:
> 
>     On 2017-01-29 04:48, John Sauter writes about labeling a positive
>     leap second 59 as done by Felicitas Arias:
> 
> > She prefers to label the leap second as a second 23:59:59, but the
> > UTC
> > definition calls it 23:59:60.
> 
>     Yes, of course -- I did not want to dispute that.
> 
>     My point was that Arias' labeling makes it clear that the
>     latest discontinuity in TAI - UTC occurred when TAI assumed
>     the value 2017-01-01 + 36 s. The ITU labeling (nor any
>     other specification in ITU-T TF.460-6) does not imply the precise
>     instant of the discontinuity, nor does IERS Bulletin C52.

Based on the definition of UTC, it seems to me that there are two
cases, both of which are very simple.  For a negative leap second, the
change in TAI - UTC happens instantly at UTC midnight, which is one
second after 23:59:58, when the difference changes by -1.  For a
positive leap second, the change happens gradually over the time of the
leap second, from 23:59:60 to midnight, when the difference slowly
changes by +1.

>     And about the "danger" of leap seconds through computer
>     failures, John Sauter writes:
> 
> 
> > I would not blame leap seconds but the programmer who did not
> > properly
> > test for leap seconds when developing his software.  Leap seconds
> > have
> > been around for over 30 years, so it isn't like they are a new
> > requirement.
> 
>     Of course you are right -- leap seconds cannot be blamed for
> computer
>     failures, but careless programmers and inconsistent or incomplete
>     program specifications may well be.
> 
>     But my point was not who or what was to blame -- I rather wanted
> to
>     indicate circumstances where even the slowest bureaucracy can
>     react swiftly in a very pragmatic manner: if the presence of
>     leap seconds might cause harm to human health then their
> abolition
>     is likely. See the introduction of the unit Sv as a special name
>     for Gy by the BIPM as an example.
> 
>     Michael Deckers.

This sounds like an interesting story--can you provide more details, or
a reference?  I was able to learn only the basic facts:

http://www.bipm.org/metrology/ionizing-radiation/units.html

    John Sauter (John_Sauter at systemeyescomputerstore.com)