Poul-Henning Kamp wrote on 2005-01-23 09:00 UTC: > >any "leap > >hours" that prevented this would, if ever implemented, be even more > >traumatic than leap seconds are now. > > they already happen here twice a year, and by now even > Microsoft has gotten it right.
OBJECTION, your Time Lords! UTC currently certainly has *no* two 1-h leaps every year. What the witness tries here is merely a poor attept to confuse the jury. He muddles the distinction between local civilian time, which we all know is entirely subject to our politicians deep-seated desires to manipulate us into getting out of bed earlier in summer, and UTC, which is what all modern computers use internally for time keeping today, below the user interface, where a 1-h leap is entirely unprecedented and uncalled for. [By the way, and for the record, may I remind the jury that the quoted Microsoft *is* actually the one large operating-system vendor who still has not quite yet "gotten it right", as all Windows variants still insist on approximating in the PC BIOS clock LCT instead of UTC. Rebooting during the repeat hour after DST *will* corrupt your PC's clock. Gory details: http:// www.cl.cam.ac.uk/~mgk25/mswish/ut-rtc.html ] > >In addition to being historically unprecedented, such a move would be > >illegal in the United States and some other countries, which have > >laws explicitly defining their time zones based on solar mean time, > >unless such laws were changed. > > The laws, wisely, do not say how close to solar mean time, and parts > of USA already have offsets close to or exceeding one hour anyway. As Ron Beard said wisely in his opening address in Torino, laws can be changed fairly easily, and this discussion should certainly not be about reinterpreting *past* legislation. Instead, it should be entirely about making a scientific, technical, and practical recommendation for *future* legislation. If you read, just one example, to deviate a bit from the overwhelmingly US/UK-centricism of this legal argument, the relevant German legislation, http://www.cl.cam.ac.uk/~mgk25/time/zeitgesetz.en.html then you will find that it consists at the moment simply of a pretty exact technical description of UTC. In other words, it follows exactly the relevant ITU recommendation! If the ITU recommendation were changed, for a good cause and with wide international consensus, I have little doubt that the German parliament and pretty much every other parliament would be sympathetic and update the national legislation accordingly. German laws are already updated almost each time the BIPM revises some aspect of the SI. Countries update their national radio interference and spectrum management legislation regularly based on the international consensus that is being negotiated within the ITU. The US and UK are actually no different from that, except that the subtle differences between GMT and UTC have escaped political attention in these two countries so far, and as a result, they still have a technically rather vague definition of time in their law books, and leave in practice all the details up to the Time Geeks as USNO, NPL, etc. If you think that discussions within the ITU should feel constrained by the legislation of individual member countries, as opposed to setting guidelines for future legislation there, then you have simply misunderstood the entire purpose of the process. Markus -- Markus Kuhn, Computer Lab, Univ of Cambridge, GB http://www.cl.cam.ac.uk/~mgk25/ | __oo_O..O_oo__