proposed time zone package change for Bangladesh

With June 16 looming and no better information available,
here's a proposed change to the "asia" file to reflect use of DST in
Bangladesh this year.

If no problems are found, expect the ftpable file to be updated 2009-06-08.

				--ado

------- asia -------
*** /tmp/geta6499	Mon Jun  1 21:55:59 2009
--- /tmp/getb6499	Mon Jun  1 21:55:59 2009
***************
*** 1,5 ****
  # <pre>
! #  <at> (#)asia	8.32
  # This file is in the public domain, so clarified as of
  # 2009-05-17 by Arthur David Olson.

--- 1,5 ----
  # <pre>
! #  <at> (#)asia	8.33
  # This file is in the public domain, so clarified as of
  # 2009-05-17 by Arthur David Olson.

***************
*** 127,132 ****
--- 127,155 ----
  			3:00	-	AST

  # Bangladesh

Re: proposed time zone package change for Bangladesh

Arthur David Olson wrote:
> With June 16 looming and no better information available,
> here's a proposed change to the "asia" file to reflect use of DST in
> Bangladesh this year.
They have finally decided now, but changed the start date to midnight 
between the 19th and 20th, and they have not set the end date yet.

Some sources:
http://in.reuters.com/article/southAsiaNews/idINIndia-40017620090601
http://bdnews24.com/details.php?id=85889&cid=2

Our wrap-up:
http://www.timeanddate.com/news/time/bangladesh-daylight-saving-2009.html

Best regards,
Steffen Thorsen - timeanddate.com

When a official time changes what's happend in real time ?

Hello,

When a TZ change in France in the middle of the night i sleep so i have 
never see if hour change in real time...

I see on 
http://en.wikipedia.org/wiki/Network_Time_Protocol#Microsoft_Windows
than W32TIME can have an 1-2 second error..

is http://www.meinberg.de/english/sw/ntp.htm is more precise ?

Have a nice day/night ;)

update to tz-link.htm

When there is a good opportunity:

*** tz-link.htm Sun May 17 11:44:05 2009
--- tz-link.htm.new     Tue Jun  2 03:00:11 2009
*************** but the maps are more up to date.</li>
*** 360,369 ****
  </ul>
  <h2>Time zone boundaries</h2>
  <ul>
! <li><a href="http://efele.net/maps/tz/us/">A map of the TZ timezones in
! the US</a> contains a <a
  href="http://en.wikipedia.org/wiki/Shapefile">shapefile</a> of the
! <code>tz</code> regions in the US.</li>
  <li><a href="http://statoids.com/statoids.html">Administrative Divisions
  of Countries ("Statoids")</a> contains detailed lists of
  <code>tz</code>-related zone subdivision data.</li>
--- 360,368 ----
  </ul>
  <h2>Time zone boundaries</h2>
  <ul>
! <li><a href="http://efele.net/maps/tz/">TZ timezones maps</a> contains 
a <a
  href="http://en.wikipedia.org/wiki/Shapefile">shapefile</a> of the
! <code>tz</code> regions in the world.</li>
  <li><a href="http://statoids.com/statoids.html">Administrative Divisions
  of Countries ("Statoids")</a> contains detailed lists of
  <code>tz</code>-related zone subdivision data.</li>

Thanks,
Eric.

RE: When a official time changes what's happend in real time ?

> Subject: When a official time changes what's happend in real time ?

> When a TZ change in France in the middle of the night i sleep so i
have
> never see if hour change in real time...
> 
> I see on
> http://en.wikipedia.org/wiki/Network_Time_Protocol#Microsoft_Windows
> than W32TIME can have an 1-2 second error..
> 
> is http://www.meinberg.de/english/sw/ntp.htm is more precise ?

That is a different subject, not really related.

The way to look at it goes like this:

1. Your computer keeps UTC.  Perhaps it has been told once and just
keeps ticking, or perhaps it is kept in sync with NTP.  In either case,
it keeps UTC with some accuracy, which depends on hardware and software.

2. The timezone (TZ setting) specifies an offset from UCT, and when --
if ever -- that offset changes.  For example, setting your TZ to France
specifies the offset is +1 hour in winter, +2 hours in summer.  When you
ask the computer to supply local time, it takes UTC plus the current
offset, that's the answer.

When the offset changes (on transition from summer time to winter time,
or vice versa), the offset simply changes.  That's not a time adjustment
in the way NTP does, it is simply a change to the offset variable.
Indeed, you do not need NTP, or the time adjusting machinery in the OS

Re: proposed time zone package change for Bangladesh

Here's an updated proposed change, reflecting the information from Steffen
Thorsen. The "asia" differences are against the current ftpable version.
We'll need to revisit Bangladesh once the 2009 end date is determined.
I've also added Eric Muller's tz-link.htm update.

Barring problems, these will show up in the ftpable version on 2009-06-08.

				--ado

------- tz-link.htm -------
*** /tmp/geta9713	Tue Jun  2 09:31:42 2009
--- /tmp/getb9713	Tue Jun  2 09:31:42 2009
***************
*** 18,24 ****
  <body>
  <h1>Sources for Time Zone and Daylight Saving Time Data</h1>
  <address>
!  <at> (#)tz-link.htm	8.19
  </address>
  <p>
  This file is in the public domain, so clarified as of
--- 18,24 ----
  <body>
  <h1>Sources for Time Zone and Daylight Saving Time Data</h1>
  <address>
!  <at> (#)tz-link.htm	8.20
  </address>
  <p>
  This file is in the public domain, so clarified as of
***************

No DST in Mauritius the coming summer

According to several sources, Mauritius will not continue to observe DST 
the coming summer, which means that the current "max" rules for 
Mauritius should probably be changed to "only" rules.

Some sources, in French:
http://www.defimedia.info/news/946/Rashid-Beebeejaun-:-%C2%AB-L%E2%80%99heure-d%E2%80%99%C3%A9t%C3%A9-ne-sera-pas-appliqu%C3%A9e-cette-ann%C3%A9e-%C2%BB
http://lexpress.mu/Story/3398~Beebeejaun---Les-objectifs-d-%C3%A9conomie-d-%C3%A9nergie-de-l-heure-d-%C3%A9t%C3%A9-ont-%C3%A9t%C3%A9-atteints-

Our wrap-up:
http://www.timeanddate.com/news/time/mauritius-dst-will-not-repeat.html

Regards,
Steffen Thorsen - timeanddate.com

tzdata mirror no longer found (in tz-link.htm)

I noticed that tz-link.htm file currently (as of the version in
tzcode2009h.tar.gz) includes a link labeled "smaller HTTP mirror" to
  http://public.planetmirror.com/pub/timezone

However, when I follow that link, the resulting page does not actually
contain any timezone-related files -- and in fact after looking around a
bit I didn't see any indication that the site still contains a separate
mirror for the "upstream" timezone database.  (Using the provided search
box to search for the word "tzdata" returned only links related to the
CentOS mirror that is hosted on the site.)

On a separate-but-related topic: I'm not sure how the 
  http://www.twinsun.com/tz/tz-link.htm
web page is normally maintained, but I noticed that while the tzcode2009h
file's version of the file contains a version stamp of "8.19", the
version posted on twinsun is only "8.15".  

I mention this especially because the page is referenced in many places
as the "home URL" of the timezone database project, so it seems like it
would be worth trying to keep it as up-to-date as possible....  

(The tz-arts.htm file on the twinsun site is also a few revions behind
the current tzcode version, for what it's worth.)

Thanks.

							Nathan
----------------------------------------------------------------------------
Nathan Stratton Treadway  -  nathanst <at> ontko.com  -  Mid-Atlantic region
Ray Ontko & Co.  -  Software consulting services  -   http://www.ontko.com/

tz file format

Re: tz file format

The line means

Until Feb 1917, add 10h offset to get standard time, and 1 more hour for 
local wall time (EST). This shortcut represents "daylight/summer' time, 
without having to use a rule record.

David Patte
Relative Data, Inc.

russ wrote:
> Hi,
>
> I hope i'm not wasting your time.  I'm attempting to read the tz 
> database into a c# application, and I'm not sure how to interpret this 
> entry:
>
> Zone Australia/Hobart    9:49:16    -    LMT    1895 Sep
>             10:00    -    EST    1916 Oct 1 2:00
>             10:00    1:00    EST    1917 Feb
>             10:00    Aus    EST    1967
>             10:00    AT    EST
>
> What is the significance of the "1:00" on the row ending in "1917 
> Feb".  Do I just add this to the 10:00 offset?
>
> Thanks,
> Russell
>
>