On Sun, 14 Dec 2008, Zefram wrote: > > NOTE These expressions apply to both UTC and non-UTC based time > scales for time of day. > > This seems to be the crucial bit that you missed. It's explicit about > allowing time scales other than UTC, and doesn't restrict the choice > of time scale at all. UT1, with strict 86400-second days, is obviously > permitted, and I suggest that vague UT per se is also a valid time scale.
Ah, yes, thanks for pointing that out, and also > *local time* > > locally applicable time of day such as standard time of day, > or a non-UTC based time of day > > You're permitted to represent, for example, the mean-solar-time-based > British legal time in ISO 8601. However... > Unfortunately ISO 8601 does not supply any way to designate UT1 or any > other flavour of UT except UTC. Thus, strictly speaking, there is no > way to designate any local time that is based on UT1 rather than UTC. So non-UTC time has only minimal support by the standard. > It seems to me that the standard would be rather more useful if "standard > time" were defined more according to its original meaning: a local time > scale defined by an offset from UT, rather than specifically from UTC. > The timezone designation material should correspondingly refer to UT > rather than UTC, and the "Z" should probably follow by designating UT. > All of these would be explicitly vague as to which flavour of UT is > being referred to. Yes, I think this kind of vagueness makes sense in a lot of situations (with appropriate caveats for applications that require subsecond precision and agreement between multiple systems). It would work for POSIX time too. Tony. -- f.anthony.n.finch <d...@dotat.at> http://dotat.at/ FORTIES CROMARTY FORTH: SOUTHERLY 5 TO 7, PERHAPS GALE 8 LATER. ROUGH OR VERY ROUGH, BECOMING MODERATE OR ROUGH. FAIR THEN RAIN. MODERATE OR POOR. _______________________________________________ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs
