[LEAPSECS] BBC radio Crowd Science

[Zefram]

Warner Losh wrote:
>changes at the start of the positive leap second, or at the start of
>the first second after a negative label has been removed. Otherwise
>the irregular radix math doesn't work out.

The maths isn't done in the irregular radix.  For the purposes of
expressions such as "TAI - UTC" that require a UTC time to be reduced to
a scalar value, that scalar is derived using the regular radix values.
This means that, yes, 2016-12-31T23:59:60 and 2017-01-01T00:00:00 have the
same scalar value.  The jump of TAI-UTC up by 1 s causes the repetition
of the preceding 1 s worth of UTC scalar values.

-zefram