🚀 go-pugleaf

In article <860028561snz129.os2.7@nexus.demon.co.uk>
           news@nexus.demon.co.uk "Dave Liquorice" writes:

> In article <860002312snz129.os2.7@corixia.demon.co.uk>
>            newsreply@corixia.demon.co.uk "Richard Ashton" writes:
> 
> >} >} Now that BST has arrived what is the correct setting for the TZ
> >} >} enviroment variable for Sendmail (v2.01).
> >} >
> >} > AIUI Set TZ = GMT0BST1 is correct.
> >}
> >} Thats what it was, through the winter, but that now produces a time tag
> >} with contents being the BST system time but with GMT appended, very
> >} wrong.
> >
> >What is correct then GMT0BST ?
> 
> Well I have TZ=BST1 at the moment an this produces a time tag with -0100 
> appended. eg "01:41:10 -0100" with the time being BST. Now to my mind 
> that is correct. That is to get UTC you take the quoted time and adjust 
> it according to the appended digits, subtract 1 hour.

No that's arsy-tarsy.  You should have TZ=BST-1 (if you want to run
throughout the year on what used to be called British Standard Time
during that disastrous experiment in the later 60s); for some ineffable
reason, those nice 'Merkins that came up with the concept of a TZ
environment variable encoded it with the hours *behind* Greenwich.

The correct designation of our present timezoen, for use on news and mail
postings, is to append "+0100" to the time, because we're on a clock
system that's one hour *ahead* of Greenwich.  This therefore provides the
basis for interpreting the time shown.  For instance, the time shown on
this posting is "09:46:31 GMT"; that's the *true* time when I started
writing it, although the current time is 10:51 BST.  Now the above is the
way that SNews handles the changes of time zone: it sticks rigidly to
posting with GMT, and therefore adjusts the time back by one hour from
the displayed time to compensate.  PCElm for e-mail, OTOH, just spits out
the clock time, so one needs to add the "+0100" designation afterwards
to show that, say, 10:46:31 is actually when using the BST time
reference; some implementations add the local alphabetic designator too,
parenthesized, thus: "10:46:31 +0100 (BST)", although RFC-822 does not
appear to allow this last addition.

Incidentally, remember that with news postings, many newsreaders convert
the time in the Date header from whatever local zone that may be into the
local time of the reader; so my posting above, were it to be read in
France, say, might appear at "11:46:31 CEST" (or whatever abbreviation
the French use for their summer time), whilst if seen in California,
where they are still on winter time, as 05:36:41 PST.  It's important,
therefore, to get the sign of the numeric timezone indicator right!

> Of course there is the other way of looking at the above, the quoted 
> time is UTC and to get local clock time you adjust according to the 
> appended digits in which case you need +0100 and the time data to be 
> UTC.
> 
> I hate the mess that PCs get into with Summer Time and Time Zones. 
> WTF can't they run internally on UTC and just display local time when 
> required and have a proper, once only way, of setting the adjustment 
> for Summer Time and the Time Zone.

Since the dates on which such changes occur is decided by the whim of
parliamentarians and similar lame-brainers, there will always be changes
to the changes :-(

-- 
Brian {Hamilton Kelly}                                         bhk@dsl.co.uk
    "We've heard that a million monkeys at a million keyboards could produce
     the Complete Works of Shakespeare; now, thanks to the Internet, we know
     this is not true."            Robert Wilensky, University of California