9fans - fans of the OS Plan 9 from Bell Labs
 help / color / mirror / Atom feed
From: erik quanstrom <quanstro@quanstro.net>
To: 9fans@9fans.net
Subject: Re: [9fans] /adm/timezone/EET is bad
Date: Mon, 28 Sep 2009 21:45:15 -0400	[thread overview]
Message-ID: <5951b8637c4bf7c8bd3515126ab454b6@ladd.quanstro.net> (raw)
In-Reply-To: <<1209a838da1003845b874b8a9ca0b4b7@isd.dp.ua>>

On Mon Sep 28 09:34:51 EDT 2009, yarikos@gmail.com wrote:
> Today I noticed my Plan 9 machine displayed time which is 1 hr past
> surrounding world.  Digging around, I found that DST start/end dates
> for Eastern-European Time (/adm/timezone/EET) for current year are
> bad.  Those follow pre-1996 conventions for ending dates and does DST
> switch 2 hours later.  For more information, see
> http://en.wikipedia.org/wiki/European_Summer_Time.
>
> Bundled program prints valid pair of dates for a given year in
> 1996-2099 range.
>
> Yaroslav.

that's pretty nifty.  i wish i had gotten my code that small.
i don't have formulae that compact.  when i generated us
time zones, i took the more intuitive approach of using
command lines like "dateof 2009 mar sun 1" or "dateof 2009
mar sun last".  that way it was easy enough to encode the
appropriate rules and generate tz files directly.

i dusted that stuff off and added eet.  the zones generated
for the us will be different by 1hr in the fall for 2007-.  repeat
2:00-3:00, not 1:00-2:00.

/n/sources/contrib/quanstro/timezone

i noticed that the system's eet starts in 1986 not 1977
as i think it should.  am i wrong?  i'm not an eet expert.

- erik



       reply	other threads:[~2009-09-29  1:45 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <<1209a838da1003845b874b8a9ca0b4b7@isd.dp.ua>
2009-09-29  1:45 ` erik quanstrom [this message]
2009-09-28 13:33 yaroslav

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=5951b8637c4bf7c8bd3515126ab454b6@ladd.quanstro.net \
    --to=quanstro@quanstro.net \
    --cc=9fans@9fans.net \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).