Re: <time> values in HTML5

Toby Inkster scripsit:

> In areas that observe daylight savings, some days are 3600 seconds
> longer or shorter than usual. [...] There are also leap seconds
> to contend with. [...] And then there's oddities like the 30th of
> December 2011 which, according to the government of Samoa, simply will
> not exist.  [...]

All of these cases except leap seconds have to do with time zones,
but the ISO 8601 / XML Schema model of time does not understand time
zones, only time zone *offsets*.  New York always has the same time zone
(U.S. Eastern, or in Olson-speak America/New_York), but its offset just
changed from -04:00 to -05:00.  Similarly, Samoa's offset will change
from -11:00 to +13:00.  That means that *given a fixed offset* 1 day is
always exactly 24 hours.

As for leap seconds, they simply aren't in the 8601 model at all.
A duration that goes through a leap second is reported as one second
shorter than a true clock will observe it to be.

-- 
John Cowan  cowan@ccil.org    http://ccil.org/~cowan
No man is an island, entire of itself; every man is a piece of the
continent, a part of the main.  If a clod be washed away by the sea,
Europe is the less, as well as if a promontory were, as well as if a
manor of thy friends or of thine own were: any man's death diminishes me,
because I am involved in mankind, and therefore never send to know for
whom the bell tolls; it tolls for thee.  --John Donne