On 6 May 2001, Rich Bowen wrote:
> On Sun, 6 May 2001 08:11:02 +0530, Abhijit Menon-Sen said:
>
> > On 2001-05-05 20:58:11, [EMAIL PROTECTED] wrote:
> > >
> > > which date format are you recommending that we use as the "common
> > > language"?
> >
> > datetime := date "T" time
> >
> > date := year month day
> > year := 4*( "0" .. "9" )
> > month := "01" .. "12"
> > day := "01" .. "31"
> >
> > time := hour minute second *( zone )
> > hour := "00" .. "23" # midnight is 00:00, not 24:00.
> > minute := "00" .. "59"
> > second := "00" .. "59" *( "." 1*( "0".."9" ) )
> > zone := "Z" | ( ("+" | "-" ) hour minute )
> >
> > Comments?
> >
> > Now is about 20010506T073000+0530 localtime, which is 20010506T020000Z.
> > Or, if you want millisecond precision, 20010506T073000.000+0530.
>
> This timezone representation makes a lot of sense, and is easy to work with.
> There's also, however, all of that named timezone nonsense ("UTC", "EST", and
> so on) which are much harder to work with, as you presumably have to have a
> comprehensive lookup table somewhere. Is this the fairly standard (or at least
> conventional) way to deal with it?
And, just to make life more confusing, Unix implements yet another
way of dealing with timezones--- the so-called Olsen timezone. Olsen
timezones are things like "US/Indiana" or "Australia/Melbourne",
and they roughly correlate to things like "EST" (UTC-5). But as far
as I know there's no One True Olsen Database that can be relied to
be the same on all Unix systems. Not to mention that Windows handles
timezones differently, as does Mac. (If anyone wants to elaborate on
platform-specific details, please do.)
Damon Chaplin of Ximian has been doing some work to come up with a
centralized conversion of Olsen timezones to UTC offsets, I
think. He's made noise about timezones extensively on the
ietf-calendar list, which is where standards get set about things
like iCalendar. For more info on that list, and a link to the
archives, see http://www.imc.org/ietf-calendar/ .
srl
--
Shane R. Landrum [EMAIL PROTECTED]
we generate our own light to compensate for the lack of light from above -AD
GPG public key: http://cs.smith.edu/~slandrum/srl_pgpkey.txt
