[LEAPSECS] Short notice for DST changes

[Rob Seaman]

For five years running the Chilean government has provided very short notice of changes to the local daylight saving time rules.  This year only 2.5 weeks advance notice (shifting off DST was scheduled for March 8):

	http://translate.google.com/translate?sl=auto&tl=en&js=n&prev=_t&hl=en&ie=UTF-8&u=http%3A%2F%2Fwww.minenergia.cl%2Fministerio%2Fnoticias%2Fgenerales%2Fministerio-de-energia-anuncia-fechas-de.html

Chile's rules are familiar because many observatories are located in that timezone, but presumably the same shenanigans play out worldwide.  It is not obvious why a couple of weeks notice is acceptable for hour amplitude clock adjustments, but six months is not acceptable for leap seconds.  And the IERS has already indicated that the six months notice could be lengthened, rather than shortened as with politically driven timezones.

While the talking point on this mailing list recently has been to hide the solar time requirement under the rug in the timezone system, elsewhere they are still talking about accumulating the embargoed leap seconds into leap minutes.  Again, not obvious why variable radix arithmetic is ok for minutes, but not for seconds.  Or for that matter why variable radix 25-hour or 23-hour days are ok for drifting timezones or other variations of the leap hour notion.

Presumably the response will be that in each case the inevitable intercalary adjustments will have been rendered less frequent.  Less frequent but far more disruptive and chaotic, and in the mean time UTC would no longer function as Universal Time.

Rob