"Joseph S. Myers" wrote on 1998-05-26 17:01 UTC:
On Tue, 26 May 1998, Olson, Arthur David wrote:
On leap seconds: having a single leap second file would eliminate the ability to have "rolling" leap seconds. (This was provided when, one year, the city of New York announced that the countdown for the dropping of the big ball that marks the beginning of the new year would run "3...2...1...LEAP...Happy New Year!", putting the leap second at midnight local time. The time zone data as distributed reflects internationally agreed leap-second-occurs-at-the-same-instant-everywhere-on-Earth behavior.)
Has anywhere (with a UTC-based time zone) ever _legally_ instituted such a move of a leap second?
There never was such a thing as a rolling leap second. If the city of New York really started to publish their own time scale with a leap second at 04:60Z = 23:60-05, then they would be running 1 s ahead of US/CA Eastern Time from 19:00 to 23:60 of their NY time. This New York counting sounds very much like an intellectual accident of someone who has heard about leap seconds but didn't understand them fully. As far as I know, there is no geographic region that uses an official time scale with leap seconds but is at the same time not defined by one (or two if summer time is used) fixed offsets to UTC. In the GPS age, there is really no point in having non-UTC-based civil time zones. Markus -- Markus G. Kuhn, Security Group, Computer Lab, Cambridge University, UK email: mkuhn at acm.org, home page: <http://www.cl.cam.ac.uk/~mgk25/>