Mark Calabretta wrote on 2006-01-17: > The way UTC is disseminated is not directly relevant to the discussion, > and I don't think I said anything about topology.
You are right, you did not mention topology. But I am still suspecting that the 60 s notation as proposed by [ITU-R TF.460] to disambiguate UTC timestamps taken during a positive leap second (and not the dissemination proper of UTC) has been one of the roots for the elaborate interpretations of UTC where UTC is not just taken as the (discontinuous) timescale TAI - DTAI. What leads me to the more pertinent question: if UTC really is just TAI in disguise, why shouldn't we adopt a new UTC as TAI - 33 s, without any disguise? Not that I am advocating the departure of civil time from solar time -- I am just checking the arguments against it. To consider UTC as a representation of TAI, you need a table of past leap seconds (when the variable radix for the second field was 59 or 61). By the same token (but without variable radix notation) you can go from TAI to TAI - DTAI. If the UTC of today gives you both TAI and TAI - DTAI then a dissemination of TAI - 33 s with the appropriate marks for leap seconds (leaps in DTAI) surely would do the same? Michael Deckers