Re: [LEAPSECS] The real problem with leap seconds

From: Mark Calabretta <mcalabre_at_atnf.CSIRO.AU>
Date: Thu, 12 Jan 2006 12:23:19 +1100

On Wed 2006/01/11 10:47:25 -0000, Michael Deckers wrote
in a message to: LEAPSECS_at_ROM.USNO.NAVY.MIL

> At some instant when TAI took a value in the positive leap second between
> 2006-01-01 + 00 h + 00 min + 32 s and 2006-01-01 + 00 h + 00 min + 33 s
> (the exact instant is not clear from [ITU-R TF.460-6 2002]), DTAI jumped
> from 32 s to 33 s; thus, UTC is not a monotone increasing function of
> TAI either.

Here in a topology-free way is what the axis labels of my graph look
like during the said leap second insertion:

            UTC axis TAI axis DTAI
       2005/12/31 23:59:58 2006/01/01 00:00:30 32
       2005/12/31 23:59:59 2006/01/01 00:00:31 32
       2005/12/31 23:59:60 2006/01/01 00:00:32 32
                        60.9 32.9 32
                        60.99 32.99 32
                        60.999... 32.999... 32
       2006/01/01 00:00:00 2006/01/01 00:00:33 33
       2006/01/01 00:00:01 2006/01/01 00:00:34 33

The seconds keep step and the graph has no gaps, jumps or kinks.

The only difference between UTC and TAI is one of representation, like
the current year which may be represented as 2006 or MMVI but it's still
the same year.

Mark Calabretta
ATNF
Received on Wed Jan 11 2006 - 17:24:06 PST